US3835850A

US3835850A - Intrauterine contraceptive device

Info

Publication number: US3835850A
Application number: US00216047A
Authority: US
Inventors: I Lerner
Original assignee: AH Robins Co Inc
Current assignee: AH Robins Co Inc
Priority date: 1972-01-07
Filing date: 1972-01-07
Publication date: 1974-09-17
Anticipated expiration: 1991-09-17
Also published as: AU4755072A; DE2253484A1; JPS4874093A; AU452379B2; FR2166927A5; BE791740A; IL40699A0; ZA727197B; GB1405765A

Abstract

An intrauterine contraceptive device made from plastic and having a perimetral ring with or without a central membrane and including short inwardly directed spurs located on each of the side portions of the perimetral ring. In addition to the inner spurs, other spurs may be located on the outer side of the perimetral ring. The outer spurs preferably have a retrograde inclination and are of decreasing length from a nose portion of the perimetral ring toward the tail portion, the nose portion being slightly wider than the tail portion providing the IUD with an inverted pear shaped outline when viewed in plan. A marker and extraction string or line is preferably secured at the nose portion but can be secured to the tail portion. Between adjacent inner spurs and between adjacent outer spurs, thin webs may be utilized to provide increased IUD surface area. The webs may or may not be secured to the spurs and may terminate between or beyond the spurs. Internal of the perimetral ring is preferably a membrane joining portions of the ring. Preferably, the membrane should provide openings at least adjacent the nose and the tail to enable use of certain types of inserters. The membrane may be secured at both sides or both ends or it may be secured by a plurality of intermediate narrow membrane portions spaced around the interior of the perimetral portion.

Description

United States Patent 191 Lerner INTRAUTERINE CONTRACEPTIVE DEVICE [75] Inventor: Irwin S. Lerner, Greenwich, Conn.

[73] Assignee: A. II. Robins Company,

Incorporated, Richmond, Va.

[22] Filed: Jan. 7, 1972 [21] Appl, No: 216,047

[52] US. Cl. 128/130 [51] Int. Cl. A61f 5/46 [58] Field of Search 128/127, 128, 129, 130, 128/260 [56] References Cited UNITED STATES PATENTS 3,467,087 9/1969 Lebech 128/130 OTHER PUBLICATIONS Dalkon Shield Publication of Aolto Robins Co., DIK- Y9FC, Nov. 1970.

Primary ExaminerRichard A. Gaudet Assistant Examiner-G. F. Dunne Attorney, Agent, or Firm-Strauch, Nolan, Neale, Nies and Kurz [57] ABSTRACT An intrauterine contraceptive device made from plas- [451 Sept. 17, 1974 tie and having a perimetral ring with or without a central membrane and including short inwardly directed spurs located on each of the side portions of the perimetral ring. In addition to the inner spurs, other spurs may be located on the outer side of the perimetral ring. The outer spurs preferably have a retrograde inclination and are of decreasing length from a nose portion of the perimetral ring toward the tail portion, the nose portion being slightly wider than the tail portion providing the IUD with an inverted pear shaped outline when viewed in plan. A marker and extraction string or line is preferably secured at the nose portion but can be secured to the tail portion. Between adjacent inner spurs and between adjacent outer spurs, thin webs may be utilized to provide increased IUD surface area. The webs may or may not be secured to the spurs and may terminate between or beyond the spurs. Internal of the perimetral ring is preferably a membrane joining portions of the ring. Preferably, the membrane should provide openings at least adjacent the nose and the tail to enable use of certain types of inserters. The membrane may be secured at both sides or both ends or it may be secured by a plurality of intermediate narrow membrane portions spaced around the interior of the perimetral portion.

66 Claims, 9 Drawing Figures INTRAUTERINE CONTRACEPTIVE DEVICE CROSS REFERENCE TO RELATED APPLICATIONS This invention pertains to improvements in the IUD which constitutes the subject matter of and is claimed in my copending application Ser. No. 775,729 filed Nov. 14, 1968 for INTRAUTERINE CONTRACEP- TIVE DEVICE, now US. Pat. No. 3,633,574, and in my copending application Ser. No. 155,769, filed June 23, 1971, now US. Pat. No. 3,782,376.

The IUDs herein disclosed can be inserted by using the inserter disclosed and claimed in my co-pending application Ser. No. 87,663, filed Nov. 9, 1970 now US. Pat. No. 3,771,520.

BACKGROUND OF THE INVENTION The invention relates to contraceptive devices, particularly those designated intrauterine contraceptive devices, hereinafter referred to as IUDs. As was reiterated in the aforedescribed co-pending application, IUDs have had increased attention toward improving their characteristics in recent years because the population rate is becoming critical throughout many areas of the world. The IUD of the afore-described earlier application introduced a new concept in effective intrauterine contraception, corresponding to the physiologic variations of the normal uterine cavity. Accommodation to variations in cavity shape and physiologic contractions was promoted by the light, flexible design and materials of exceptional resilience. The IUD, as basically taught in the afore-described applications, is engineered so that expulsive contractions directed against the broad upper portion results in flaring and flexion at the apex, increasing resistance to expulsion. The high degree of flexibility of the plastic IUD device together with the central membrane and the side spurs are believed to contribute the major force of the effectiveness of applicants IUD, and those details have been set forth clearly in the afore-described earlier application. The central membrane assures increased endometrial surface contact, guards against embedment and against intestinal strangulation in the event of perforation as reported with closed loop designs. Those features make the IUD with central body, side spurs and central membrane well tolerated by nulliparous as well as multiparous patients, and result in enhanced use-effectiveness in professional practice. That IUD has an extremely low pregnancy rate, expulsion rate, removal for medical reasons, and personal removals.

Nevertheless, there is constant development under way to improve construction of IUDs in an attempt to obtain the ultimate which is 100 percent effectiveness in comfort, retention and contraception and the improvements of this invention are directed toward such a more effective IUD.

SUMMARY OF INVENTION The present invention involves improvements, which increase the area of the basic IUD with spurs and that is accomplished in all cases in this invention by inclusion of spurs extending inwardly from a perimetral portion, in conjunction with other structural aspects: e.g., increasing the number of spurs by using inner and outer spurs; making the spurs bulbous; inserting thin webs between the side spurs; and providing various forms of central web or webs secured to the perimetral portion. In addition to the foregoing it is also proposed that rather than have the spurs extend in the same horizontal planar configuration of the perimetral portion, the spurs may be inclined, i.e., extend upward or downward or in both directions relative to the planar area. Furthermore, the internal and the external perimeter of the rim may be provided with two or more rows of fins which would enable better retention within the uterus. The tissue of the uterine cavity can enfold and grow around the spurs, in essence grabbing and firmly locating the IUD within the uterine cavity.

In addition to the foregoing improvements, the marker or telltale string or line can be secured to the nose as an alternative to being attached to the rail end of the IUD. In such case, if removal is indicated, steady traction on the telltale line causes the IUD to invert and permit a nose first withdrawal, whereby passage through the cervical canal is facilitated because the outwardly extending spurs, which have a retrograde inclination, will collapse in the manner for which they were designed for ease of introduction into the uterus.

Accordingly, a primary object of this invention resides in an improved intrauterine contraceptive device. In this regard the improvements include provision of larger IUD surface areas for greater endometrial surface contact including inwardly directed spurs and, as desired, more spurs, webs between spurs and even extending beyond the ends of the spurs, enlarged portions of the spurs, and relocation of the telltale or marker string to an attachment point at the nose of the IUD to invert the IUD For removal with the nose end first.

It is also an object to provide an improved IUD with a perimetral portion and including at least inwardly directed spurs on said perimetral portion and having benefits of the unique IUD set forth in co-pending applications Ser. No. 775,729 (U.S. Pat. No. 3,633,574) and Ser. No. 155,769 (U.S. Pat. No. 3,782,376). As with those IUDs, the IUD of this invention readily accommodates itself to various uterus sizes; resists expulsion through the cervical os; is easy to insert; and its shape and central membrane prevents possibilities of strangulation which can occur if an open type device should protrude or escape into the peritoneal cavity.

Other objects reside in the provision of an improved IUD which includes a central body with a perimetral portion having a nose, tail and side portions with a plurality of short spurs extending inwardly from the perimetral portion, with additional improved IUD surface configurations which can be one or any combination of: a plurality of short spurs extending outwardly from each of the side portions; enlarged terminal parts of the inner or outer spurs or both; increased numbers of spurs, as by providing more than one row or inner or outer spurs or both on each side portions and varying the relative locations of the spurs in the plural rows; adding thin webs between spurs, either connected to or disconnected from the adjacent spurs and even extending beyond the ends of the spurs; and modifying a central web to make it more flexible by securing it to an inner perimeter of the perimetral portion by a plurality of spaced apart thin integral membrane portions. Enlarged terminal end portions of the spurs can be provided by gradually increasing the spur width from a narrow waisted inner part joined to the perimetral portion,-to the projected end of the spur thereby providing a bulbous spur. Alternatively, the spurs can terminate in small spherical knobs or the like.

Other objects reside in providing an IUD in accord with any of the foregoing objects made from a light flexible plastic such as ULTRATHENE, polyethylene, polypropolene, ethylene, propylene, and other suitable plastic materials. In this conjunction the IUDs can, if desired, be treated by adding other materials in the form of powders molded with the plastic or coatings to enhance the ability to locate the IUD when placed and to enhance contraceptive effectiveness.

Further novel features and other objects of this invention will become apparent from the following detailed description, discussion and the appended claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS Various structural embodiments of this invention are disclosed in the accompanying drawings, in which:

FIG. 1 is an enlarged plan view of one embodiment of an IUD made in accord with the present invention showing spurs located on and directed inwardly from a perimetral portion as well as having outwardly directed spurs with retrograde inclination, the spurs being bulbous and with webs between and interconnecting the spurs;

FIG. 2 is a view looking down at the top of the IUD in FIG. 1 and shows an alternating offset angularity of the spurs so they are inclined to both sides of the planar configuration of the central IUD body;

FIGS. 3 and 4 depict another embodiment of an IUD in accord with the present invention and are respectively similar to FIGS. 1 and 2 with the exception that the outwardly extending spurs have been omitted;

FIG. 5 is a plan view of a further IUD embodiment with inwardly and outwardly directed rows of spurs extending from the perimetral portion similar to the IUD in FIG. 1 but with the central membrane extending between side portions of the ring, enlarged webs between adjacent ones of the outer spurs and no webs used between adjacent ones of the inner spurs;

FIG. 6 is a plan view of a further IUD embodiment two rows of inwardly directed spurs, without outer spurs, having a central membrane and small webs interconnecting adjacent ones of the spurs;

FIG. 7 is a longitudinal cross-section taken on line 7-7 of FIG. 6 and shows the two rows of inwardly directed spurs with each row having an inclination away from the central membrane; and

FIGS. 8 and 9 are views of another embodiment of IUD on a smaller scale but respectively similar to FIGS. 6 and 7 with the exception that the spurs extend free without small webs between adjacent ones of the spurs.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Each of FIGS. 1, 3, 5, 6 and 8 in one or more respects illustrate different features of the present invention. Many of such features from one of those Figures can be interchanged or used in conjunction with the features of other Figures, but for convenience of keeping the drawings within reason all such possible combinations of features have not been illustrated. For example, projected webs can be used with any kind or arrangement of adjacent spurs, single row or plural rows, and the web may or may not be connected to the adjacent spurs.

Turning first to FIG. 1, an IUD 20 is shown which consists of a perimetral ring 22, somewhat elongated and having a plan view like an inverted pear shape. The wider end of IUD 20 is the nose 24 and the smaller end is the tail 26 and the nose and tail are joined by two side portions 28 and 30. A thin membrane 32 is disposed across the major central area within the inner perimeter of the ring 22 and, as shown, is attached essentially along the inner edge of the nose and

tail portions

24 and 26 and provide a first aperture 34 adjacent the nose end 24 and a second aperture 36 adjacent the tail end 26. Either or both of apertures 34 and 36 can be circular, as is 34, or non-circular, as is 36. A plurality of

short spurs

40, 42, 44 and 46 extend outwardly from ring side portion 28 and

complementary spurs

48, 50, 52 and 54 extend outwardly from the opposite side portion 30. While four spurs are disclosed, the number of spurs on each side could be a different plurality (see co-pending application Ser. No. 155,769). Thin

scalloped webs

56, 58 and 62 are secured to the ring side portion 28 between and attached to adjacent ones of spurs 40-46 and

complementary webs

62, 64 and 66 are secured to the opposite ring side portion 30 between and attached to adjacent ones of spurs 48-54. Centrally located on the nose 24 are small retention grooves 68 and 70 which enable a marker line or telltale string 72 to be tied at the apex of the nose.

IUD 20 also has a set of inwardly directed short spurs 76, 78, extending from the inner perimeter of the perimetral side portion 28 and a set of inwardly directed spurs 82, 84, 86 extending from the opposite perimetral side portion 30. To provide additional IUD area for endometrial surface contact scalloped webs such as 90, 91, 92 and 93 are located between the inner spurs, attached to the ring perimeter and to the sides of the inner spurs. The ends of all spurs are preferably blunted to eliminate sharp ends or edges.

As is apparent in the embodiment of FIGS. 1 and 2, the inner spurs 76, 78 and 80 of one side row and the corresponding inner spurs 82, 84 and 86 of the opposite side row are disposed at different angles relative to the planar configuration of the perimetral ring 22 (as seen in FIG. 2) so spurs 76 and 82 incline up from the ring, spurs 78 and 84 are co-planar with the ring and spurs 80 and 86 incline down from the ring. The outer spurs 40-54 can be disposed with alternate opposite inclinations up and down from the planar configuration of the ring 22, as is shown. Alternatively, all of the spurs, both the outer spurs 40-54 and the inner spurs 76-86 can be made to extend co-planar with the perimetral ring 22. The webs between any spurs can either be made integral with the spurs or can be separated from the spurs or they may be short and scalloped as in FIG. 1 or made to extend out beyond the spurs as is shown in FIG. 5. The spurs can be shaped with cross sections and any of the various shapes as disclosed in the aforedescribed co-pending applications, although it is preferable that the plan shape of the spurs be bulbous, either with an enlarging taper toward the ends as shown in FIGS. 1-7 or with spherical knobs on the ends of the spurs as shown in FIGS. 8 and 9.

Although it is not necessary, it is preferred that the membrane 32 be discontinuous to provide the nose and tail apertures 34 and 36 to enable an efficient insertion with a stick type inserter (not shown) described structurally and functional in the afore-described copending inserter application. Other types of inserters may be used, in which case one or both of the membrane apertures may be eliminated. Alternatively the membrane can be eliminated or made in other configurations, such as has been described in the aforementioned co-pending applications.

The perimetral ring 22 provides the structural framework of device 20, and its pear shape functions to maximize the likelihood that the IUD will be retained in place after insertion in the uterus. Specifically, the ring 22 is designed to make the device flexible enough so that it yields when placed in hoop compression by the natural muscular activity of the uterus. If the device resisted such pressures unyieldingly, it might be moved in the direction of the cervical os, act as a dilating wedge, and eventually be expelled.

The cross-section of the perimetral ring portion 22 is substantially rectangular with rounded corners throughout the perimeter of the ring, but in either or both of the nose and tail regions the ring thickness is normally made greater in the direction parallel to the plane of the ring than it is in the direction perpendicular to that plane.

The general cross-section of the ring has a thickness dimension of approximately 1.5 mm. perpendicular to the plane and parallel to that plane, although it may be increased, e.g., to approximately 3.0 mm., in both dimensions at either or both of the nose or tail portions. This enables a slightly stronger rim portion where the marker string is attached and also when the ring 22 is subjected to hoop compression applied to the sides by the adjacent uterine walls, it will buckle first in the side regions.

One advantage of this function is that the intrauterine device 20 tends to deform in response to such compression, rather than to be cammed longitudinally relative to the uterine wall. If the ring 22 buckled first at the nose region 24, it would be subject to a camming force tending to move it toward the cervical os, with expulsion as a possible consequence. Thus the tendency of the ring 22 to first buckle in the side regions 28 and 30 helps to prevent expulsion. A second advantage resulting from such side buckling has to do with deformation of the central membrane 32 as is discussed below. The device 20 does not suffer from the disadvantage of the long-line type of intrauterine devices which are so flexible that one can be deformed by uterine contractions into a linear shape and thus expelled through the cervical os by a reversal of the insertion process.

However, while the ring shape and size result in response to external forces on the perimeter by deforming the entire device in a non-planar manner, the addition of the membrane 32 also enables the desired deformation whether the ring cross-section is rectangular or round or made with almost any geometric shape. When the device 20 with a central membrane 32 is subjected to external forces around its perimeter, the spurs -54 deflect initially in response to these forces and then transmit these forces to the ring 22. As the ring tends to collapse, portions of the membrane 32 respond to the compressional forces by becoming non-planar and other portions of the membrane have a resultant force in tension causing the ring to deflect in a non-planar manner in the region where the membrane in tension is attached to the ring. Side forces on the device cause non-planar deformation of the device, and, in particular, will cause the tail region to deflect out of the planar configuration and away from the cervical exit through the os.

Ring 22 has overall dimensions which are designed to correspond to the midrange of average uterine sizes, the uterus being in normal condition, while at the same time making sufficiently firm contact with the wall surfaces of any size uterus to be firmly retained in place. Specifically, ring 22 is of a generally elliptical (pearshaped) configuration in that the outside dimension of the ring along the nose-t'o-tail axis is greater than the maximum outside dimension along an axis transverse thereto. The preferred outside dimension of the ring 22 along the nose-to-tail or major axis is approximately 21 mm., and a preferred range of major axis outside diameters is from 19 to 31 mm. The preferred maximum dimension of the ring 22 in a direction transverse to the major axis is 16 mm. although a preferred range of outside diameter is from 12 mm. to 27 mm. The maximum transverse width of the ring 22 is reached at a location closer to the nose end of the device, region 24, than to the tail end, region 26. This is related to the fact that the curvature of the ring 22 at the nose of the device is more blunt, compared to the ring curvature at the tail end which is more pointed. The resulting trilobite, or buglike shape of the ring further increases the tendency of the device 20 to resist being expelled tailward through the cervical os, since, apart from any consider-. ations of buckling, an object under sideways compression tends to be cammed toward its wider end, in this case the nose region 24. I

The outside dimensions referred to so far in this de-. tailed description have to do with the dimensions of the ring 22 alone. The lateral dimensions of the entire intrauterine contraceptive device22, including the outside spurs, are greater than those previously noted. In the embodiment of FIG. 1, there are four such outside spurs 40-54 on each side of the ring 22.

Thelongest ones

40 and 48 are located nearest to the nose end of the device, and the spurs decrease progressively in length as they approach the tail end. Moreover, while the spurs may do so they preferably do not extend outwardly from the ring in a radial direction from the ring but have a retrograde inclination, in other words, they slant toward the tail end of the device 20 so as to form an acute angle (from to 15) with the major axis of the ring. The value of that angle preferably decreases progressively from the foremost spurs 40 and 48 through the rearrnost46 and 54. While it is preferred that the spurs extend outwardly from the perimeter of ring 22 along the general plane for which the ring is situated, this is not necessary. The spurs may extend away from ring 22 at angles to the general plane of the ring.

The foremost spurs 40 and 48 are preferably about 5.1 mm. long, measured from the outermost tip of the spur to the point at the base of the spur where its longitudinal axis intersects the extrapolated surface of the ring 22. An approximate range for this dimension is from about 2.5 mm. to 9.0 mm. The forwardmost spurs 40 and 48 are swept back at preferred angles of about 50 to the major axis of device 20.

The fourth set of

spurs

46 and 54, those closest to the tail end, have preferred lengths of about 2.5 mm. A range of about 1.2 mm. to 3.7 mm. is preferred although other lengths outside of this range are useful.

Spurs

46 and 54 are swept back at preferred angles of about 30 to the major axis.

The intermediate

second spurs

42 and 50 and

third spurs

44 and 52 have lengths and inclined angles intermediate those described for the first set and fourth set of spurs.

All of the dimensions above and hereafter set forth are merely preferred dimensions and ranges. However, wide variations in any given dimension and in relative dimensions, even beyond the limits of the preferred ranges, may be employed, and moreover the described relative lengths of spurs 40-46 and 48 through 54, while preferred, are not critical and the forward spurs can even be longer than those located further to the rear than the differences between the aforedescribed front and rear spur dimensions.

The outside spurs serve a number of functions. They flex to a disposition closer to the ring 22 in response to the natural muscular contractions of the uterus, and thus help the overall device to yield to such contractions rather than resisting which would increase the chances of expulsion through the cervical os. The flexibility of these spurs also permits the device 20 to fit a greater range of uterine sizes, since the spurs can either remain spread out to contact a larger uterine cavity or can flex inwardly to accommodate a smaller one, while still helping to retain the device 20 in place.

Additionally, because the spurs are resilient cantilevers, particularly in a direction along the general planar configuration of the ring, they will yield to muscular contractions transverse to their length and by so yielding, apply a self-restoring force against the uterine wall to maintain the device in its proper position.

Most significantly, however, the outside spurs have a preferential retrograde direction of slant towards the tail end of the device 20 which serves to impede retrograde movement of the device 20 in the direction of the cervical os. The device is inserted nose end first; i.e., the region 24 enters the uterus first, followed by the intermediate parts and then the tail region 26. As a result,-

reverse movement of device 20 goes against the grain (slant) of the spurs. In order to move in the reverse direction the spurs would have to be flexed outwardly from the ring 22, which increases their spread and hence is not easily accomplished. By resisting such deformation the spurs impede reverse movement of the device. In contrast, upon initial insertion of the device the spurs are more easily flexed rearwardly, i.e., bent in closer to the ring 22, so that they offer considerably less resistance to movement in the direction of insertion.

The bulbous terminal portions of the spurs are larger than the waist portions and the spurs are thicker in the direction perpendicular to the plane of the ring 22 than they are in the direction parallel to the plane. For convenience this shape may be termed tear drop inasmuch as it has an elongated teardrop profile in plane view. As a result of this difference in the thickness in the two directions and the substantially less thickness at the waist of the spurs, the outside spurs flex readily toward the ring 22, while it is relatively more difficult to deflect them in a direction perpendicular to the plane of the ring 22. Thus the spurs can easily yield during; initial insertion of the device 20, but it is undesirable that they be deflected too far out of the plane of the ring since that would make them less effective in impeding reverse movement of the device.

In this teardrop embodiment of both the inside and outside bulbous spurs, the cross-section of the spurs gradually increases from the narrow waist portion as the terminal end is approached. Such bulbous spurs have larger areas than straight narrow spurs yet the desired flexibility of spurs in a direction parallel to the plane of the ring is retained because of the narrow waist while the bulbous shape of the spurs provides an increased IUD surface area for contacting the uterus. Moreover the one or more rows of inwardly directed spurs provides still more IUD surface area for contacting the uterus. The inwardly directed spurs also provide additional appendages which can be enfolded by uterus tissues to help locate and maintain the IUD in proper disposition within the uterus.

The thin walled scalloped webs 56-60 and 62-66 between adjacent outside spurs 40-54 as well as the webs -93 between the inside spurs and the inner surface of the perimetral ring 22 serve primarily to provide additional IUD surface area. Such webs may be in or angled away from the plane of membrane 32, they may be disposed wholly between and integral with the spurs, as depicted in FIG. 1 or the webs may be disposed loose from some or all of the spurs and integral only with the side portion of the ring. If the webs are integral with the spurs it decreases the flexure of the spurs which may be desirable in smaller sizes of IUDs for nulliparous patients and if loose from the spurs, it enables substantial flexibility of the IUD for more patient comfort.

In any event the inwardly directed and increased size of the bulbous spurs and the added areas afforded by the webs, whether joined to the spurs or not, assures increased endometrial surface engagement which enhances contraceptive effectiveness. The webs provide such function with relatively large areas of surface which helps prevent embedding of the device yet the open areas around the spurs permit enfolding of such appendages by the uterus tissues to help locate and maintain location of the IUD once it is properly placed within the uterus.

Referring back to the membrane 32, one of its functions is to block the interior of ring 22 so as to prevent intrusion of intestinal tissue thereinto in the event the device 20 should be partially or completely perforated into the peritoneal cavity. Moreover, the membrane 32 is thin enough to be very flexible, the preferred thickessh ins n y ab .m -i a thfi nrefsr Isaa qtthiq ws being m a t-95,99 t Linn Because of such flexibility, when the ring 22 is under hoop compression by uterine muscles, the membrane has a tendency to buckle out of the plane of the ring 22 and consequently to bear against the internal wall of the uterus. This additional contact against the uterine wall is a further factor in resisting expulsion of the IUD 20 when muscular contractions take place.

Discontinuity of membrane 32 at

locations

24 and 26 is preferably made to the extent of providing the two

distinct openings

24 and 26, previously mentioned as among the general features of the IUD 20. The nose opening 24 is useful for cooperation with certain types of uterine insertion devices, while tail opening 26 is useful for cooperation with an extracting hook. Some inserters do not require openings. However, as has been herein described, the nose and tail openings are utilized with the special inserter described in the aforedescribed copending inserter application.

From the nose or tail end of the device the telltale string 72 will extend out through the cervical os so that the presence of the IUD can be verified by vaginal examination. The telltale string 72 may be tied around or otherwise secured to the ring 22 at the nose 24 or tail 26. For example, as an alternative to tying the string, a small hole (not shown) may be provided for the purpose of inserting and securing string 72, or the cord may be secured or made by molding it integral with the remainder of device 20 thereby eliminate the connection problem and costs incurred therewith.

IUD (FIG. 3)

The IUD 100 shown in FIG. 3 is identical to the IUD 20 shown in FIG. 1 excepting that it does not have outside spurs. It has a perimetral rim 122 with nose 124 and tail 126, the rim being somewhat pear-shape in plan view. The inner membrane 132, just as has been described for membrane 32, extends from adjacent the nose 124 to adjacent the tail 126, providing the nose opening 134 and tail opening 136 which enables use of a stick inserter as has been described.

The two rows of inwardly directed spurs 138, 140, 142 and 144, 146, 148 have scalloped webs such as 150, 152, 154 and 156 which adjoin the spurs and the inner perimeter of the perimetral ring 122, as was described for the IUD 20 of FIG. 1. As depicted, the inwardly directed

spurs

138, 140 and 142 along one side of the IUD ring 122 have different inclinations to the planar configuration of the ring 122 but may be disposed in the plane of the ring 122 if desired. The crosssectional shape of the ring 122 and the inside spurs are similar to that which has been described for IUD 20 of FIG. 1 and the trilobite shape of the IUD, the shape and area of the bulbous spurs, the webs between the spurs and the central membrane 132 serve the same purposes and accomplish the same IUD functions as has been described for the corresponding elements of IUD 20 in FIG. 1.

IUD (FIG.

The IUD 180 of FIG. 5 includes a perimetral pearshaped ring 182 with wide nose portion 184, narrow tail portion 186, a central membrane 188 adjoining side portions of the ring 182 leaving nose opening 190 and tail opening 192 for use of a stick type of inserter. A telltale (removal) cord 194 is tied to the nose portion 184 for purposes as described in connection with IUD of FIG. 1.

. This embodiment of IUD 180 has outside spurs as well as the inwardly directed spurs. The outside spurs 196, 198, 200 and 202 along one side of the ring 182 and outside spurs along the other side of the ring correspond in shape to the outer spurs described for IUD 20 of FIG. 1, the difference being that the disclosed

thinwalled webs

212, 214, 216, 218, 220 and 222 which are disposed between adjacent ones of the outside spurs extend outward from between the pairs of adjacent spurs to protrude beyond the ends of the spurs. The webs 212-222 are secured to the perimetral rim as well as to theadjacent spurs and provide stiffness for the spurs, however the webs may be made so they are not joined to the spurs, being secured only to the perimetral ring and thereby enabling normal flexure of the spurs.

In this FIG. 5 embodiment of IUD 180, the inwardly directed

spurs

224, 226 and 228 constitute one side row and spurs 230, 232 and 234 constitute another side row of spurs. All inner spurs 224-234 are bulbous, being teardrop in shape and are disposed to one side of and inclined away from membrane 188. Complementary rows of inner spurs can be provided on the opposite side of membrane 188 if so desired. The inner spurs 224-234 are depicted without thin webs between spurs but such webs, of any desired length, e.g., scalloped, even, or protruding, could be provided as desired to add surface area to the IUD.

The large protruding webs 212-222, between outer spurs are preferably located at the mid-plane of the perimetral ring in the same plane in which the membrane 188 is located, but they could be offset if desired. The webs and the bulbous spurs on the inner perimeter of the ring 182 assure a substantial increase in endometrial surface contact and hence increase the contraceptive effectiveness of the IUD.

The number of spurs in each row, outside as well as inside can be different from the number depicted in the drawing, e.g. three or five could be used in each outside row and, as shown in FIGS. 6 and 8, the number of spurs in each inside row can be varied.

IUD (FIG. 6)

The IUD 240 shown in FIGS. 6 and 7 has no outside spurs and is similar in overall shape to the IUD shown in FIG. 3. The perimetral ring 242 has essentially the same pear-shape and cross-section as does ring 122 with the wide nose portion 244, narrow tail portion and a telltale cord 248 tied to the nose. The thin-wall central membrane 250 extends over most of the inside area encompassed by ring 242 being discontinuous only at the

openings

252 and 254 adjacent the nose 244 and tail 246, respectively.

On each side of membrane 250, a plurality of inwardly directed spurs project from the inner perimeter of ring 242, being spaced apart along the entire ring perimeter. Spurs 256274, seen in FIG. 6 project inwardly with an inclination away from membrane 250. The two

spurs

256 and 274 adjacent the nose portion 244 and the two

spurs

264 and 266 adjacent the tail portion 246 are spaced on either side of the longitudi nal axis of the IUD 240 and, as distinguished from the other adjacent spurs, are not joined by thin-walled webs. This construction provided freedom of access to the nose opening 252 and tail opening 254 through which the stick inserter, as described in the aforementioned applications, must project during its use. Situated between adjacent ones of spurs 252-274, other than the two pairs just described as adjacent the nose and the tail, are thin-wall web members such as

webs

276, 278, 280 and 282. The webs are attached to the perimetral ring 244 and, as desired, may or may not be secured to the adjacent spurs, and can be used or omitted between any adjacent two spurs. As clearly shown in FIG. 7, a similar group of inwardly directed spurs with thin wall webs between adjacent spurs are located in spaced apart relationship around the inner perimeter of the perimetral ring 242 on the opposite side of the central membrane 250 from the side shown in FIG. 6, and inclined away from the central membrane in a direction opposite from that of the spurs 256-274 seen in FIG. 6.

The large area of central membrane 250, the bulbous shape of the multiple spurs on both sides of the membrane and the large surface area of the thin wall webs between spurs provide IUD 240 with a very large IUD area for contact with the endometrial surface of the uterus, thus providing increased contraceptive effect in a small overall boundary zone.

When using a different kind of inserter other than the stick inserter, the central membrane of any of the IUD embodiments herein described and contemplated may be imperforate adjacent the nose and tail portions of the perimetral ring thereby further increasing the IUD surface area. The webs between adjacent spurs may be made of any desired length, i.e., shorter than the spurs, the same length or greater in length. Preferably the webs are not connected to the spurs which provides flexibility of the device. It appears desirable that the tissues within the uterus at least partially enfold the terminal portions of spurs on both sides of the central membrane to help maintain the IUD in proper position within the uterus.

IUD (FIG. 8)

The IUD 290 illustrated in FIGS. 8 and 9 is essentially similar to IUD 240 of FIG. 6. The difference is that the inwardly directed bulbous spurs 292 have knob-shaped ends 294 instead of being teardrop shape and the webs between spurs are not present. As in the other IUD embodiments, a telltale, or marker, cord 296 is secured to the nose and the IUD 290 includes openings in the central membrane adjacent the nose and tail to enable use of a stick type inserter. Bulbous spurs with the spherical knob-like ends as shown in FIGS. 8 and 9 can be used on any of the aforedescribed embodiments.

Another way to make the central membrane in an IUD such as shown in FIGS. 5, 6 and 8 is to have the central membrane area suspended by narrow thin wall membrane bridges (not shown), providing the inner membrane body with additional flexibility whichcan assure disposition to provide maximum endometrial surface contact.

. As described, each of the IUD embodiments such as 20, 100, 180, 240, 290 and others which can be understood from this disclosure, preferably consist of a single piece of integrally molded plastic material which preferably has been mixed with a suitable amount of radioopaque material to permit the device to be located by X-ray or fluoroscope techniques if necessary. A preand other metals. The coating may be vapor-deposited to a preferred thickness of approximately X inch. A preferred range of coating thickness is from 2 X 10 to 40 X 10 inch.

The invention may be embodied in other specific forms without departing from the scope, spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope and spirit of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

ferred plastic material is Ultrathene, a copolymer of ethylene, and a vinyl monomer material, catalogue listing UE632 (UE633 is also very satisfactory) of U.S. Industries, with 12 percent by weight of .barium sulfate as a radio-opaque ingredient. While the proportions just mentioned are preferred, the range of barium sulfate may be anywhere from 0 to 40 percent. Alternative plastic materials which may be employed are polyethylene, polypropylene, ethylene, propylene, copolymers, and terpolymers, e.g., EPT, polyvinyl acetate, copolymers of vinyl acetate with another ethylenically unsaturated monomer copolymerizable therewith, silicone rubber, polyfluoroethylenes, e.g. Teflon, Kel-F, etc., and the like.

In accordance with one feature of this invention, the molded IUD device may be provided with a thin coating of a suitable material or impregnated with a suitable material in powdered form to inhibit the deposition of calcium upon the IUD after it has been in the uterus for a period of time and to otherwise enhance its effectiveness. Such materials include gold, platinum, silver, copper, zinc, tantalum, as well as alloys and salts of these 1. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, and a plurality of spaced apart short rod-like spurs extending inwardly from each side portion of said perimetral portion.

2. An intrauterine device as defined in claim 1, wherein pull line means are secured to the nose portion of said intrauterine device to enable removal after insertion.

3. An intrauterine device as defined in claim 1, wherein thin webs integral with the edge of said perimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs.

4. An intrauterine device as defined in claim 3, wherein said thin webs are disposed between all adjacent pairs of short spurs on each of said side portions.

5. An intrauterine device as defined in claim 3, wherein each of said thin webs between adjacent spurs is attached to said edge of said perimetral portion and is also secured to said adjacent spurs.

6. An intrauterine device as defined in claim 3, wherein each of said thin webs is shorter than the length of said adjacent spurs.

7. An intrauterine device as defined in claim 1, wherein each of at least a portion of said spurs has an enlarged bulbous terminal portion.

8. An intrauterine device as defined in claim 7, wherein the portion of each bulbous spur located near said perimetral portion has a smaller cross-section than that of the portion adjacent the spur terminal end.

9. An intrauterine device as defined in claim 8, wherein each of the bulbous spurs has an effective teardrop configuration.

10. An intrauterine device as defined in claim 8, wherein the terminal end of each bulbous spur has an enlarged knob.

11. A device as defined in claim 1, made from a plastic material comprising an ethylene vinyl copolymer.

12. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; and a plurality of rows of spaced apart short spurs extending inwardly from said perimetral portion including plural rows on at least each of said two side portions.

13. An intrauterine device as defined in claim 12, wherein the spurs in all of said rows on each of said side portions are side by side in a direction normal to the general planar shape of the device.

14. An intrauterine device as defined in claim 12, wherein the spurs in one of the adjacent rows on each side of said side portions are offset from the spurs in another of said adjacent rows on the same side of said side portion in a direction along the perimetral portion.

15. An intrauterine device as defined in claim 12, wherein pull line means are secured to said intrauterine device to enable removal after insertion.

16. An intrauterine device as defined in claim 12, wherein thin webs integral with said perimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs.

17. 'An intrauterine device as defined in claim 16, wherein each of said thin webs between adjacent spurs in a row is attached only to said perimetral portion and is disposed loose between said adjacent spurs.

18. An intrauterine device as defined in claim 16, wherein each of said thin webs is shorter than the length of said adjacent spurs.

19. An intrauterine device as defined in claim 18, wherein said shorter thin webs are disposed between all adjacent pairs of short spurs on each of said side portions. 7

20. An intrauterine device as defined in claim 18, wherein each of said shorter thin webs between adjacent spurs is attached to said perimetral portion and is also secured to said adjacent spurs.

21. An intrauterine device as defined in claim 16, wherein said thin webs integral with the perimetral edge portion protrude outwardly from said perimetral portion a distance greater than the length of said adjacent spurs.

22. An intrauterine device as defined in claim 21, wherein each of said protruding thin webs between adjacent spurs is attached only to said perimetral portion and is disposed loose from said adjacent spurs.

23. An intrauterine device as defined in claim 12, wherein said central body includes a perimetral rim with thin membrane means across the area circumscribed by said perimetral rim.

24. An intrauterine device as defined in claim 23, wherein said membrane means is connected to said perimetral portion by a plurality of bridge portions and provides openings at least adjacent said nose portion and said tail portion.

25. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, and at least three spaced apart short projections extending inwardly from each side portion of said perimetral portion.

26. An intrauterine device as defined in claim 25, further comprising a plurality of spaced apart short projections extending outwardly from said perimetral portion.

27. A device as defined in claim 26, made from a plastic material comprising an ethylene vinyl copoly' mer.

28. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral rim portion with nose, tail and'side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart spurs extending inwardly from said perimetral portion; and thin membrane means connected to said rim portion and extending across the area circumscribed by said perimetral rim portion.

29. An intrauterine device as defined in claim 28, wherein said membrane means is connected to said perimetral portion by a plurality of bridge portions and provides at least openings adjacent said nose portion and said tail portion.

30. An intrauterine device as defined in claim 28, wherein said membrane means is discontinuous at least at each side portion.

31. An intrauterine device as defined in claim 28, wherein thin webs integral with the inner edge of said perimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs.

32. An intrauterine device as defined in claim 31, wherein each of said thin webs between adjacent spurs is attached to said edge of said perimetral portion and is also secured to said adjacent spurs.

33. An intrauterine device as defined in claim 31, wherein each of said thin webs is shorter than the length of said adjacent spurs.

34. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; and a plurality of short spurs extending outwardly from each of said side portions.

35. An intrauterine device as defined in claim 34, wherein all of said outwardly extending spurs have a retrograde inclination toward the tail portion.

36. An intrauterine device as defined in claim 34, wherein thin webs integral with the outer edge of said perimetral portion are disposed on each side portion between at least two adjacent ones of said outwardly extending short spurs.

37. An intrauterine device as defined in claim 36, wherein said thin webs are disposed between all adjacent pairs of short spurs on the inner side and on the outer side of each of said side portions.

38. An intrauterine device as defined in claim 36, wherein each of at least some of said thin webs between adjacent spurs is attached to said edge of said perimetral portion and is also secured to said adjacent spurs.

39. An intrauterine device as defined in claim 36, wherein each of at least some of said thin webs is shorter than the length of said adjacent spurs.

40. An intrauterine device as defined in claim 34, wherein said central body includes a perimetral rim with thin membrane means across the area circumscribed by said perimetral rim.

41. An intrauterine device as defined in claim 40, wherein said membrane means is connected to both side portions and provides openings adjacent said nose portion and said tail portion. v

42. An intrauterine device as defined in claim 40, wherein said membrane means is connected to said perimetral portion by a plurality of bridge portions and provides at least openings adjacent said nose portion and said tail portion.

43. An intrauterine device as defined in claim 40, wherein said membrane means is discontinuous at least at each side portion.

44. An intrauterine device as defined in claim 40, wherein all of said outwardly extending spurs have a retrograde inclination toward the tail portion.

45. An intrauterine device as defined in claim 40, wherein thin webs integral with said perimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs on each of said side portions.

46. An intrauterine device as defined in claim 45, wherein said thin webs are disposed between all adjacent pairs of short spurs on each of said side portions.

47. An intrauterine device as defined in claim 45, wherein each of said thin webs between adjacent spurs is attached to said edge of said perimetral portion and is also secured to said adjacent spurs.

'48. An intrauterine device as defined in claim 45, wherein each of at least some of said thin webs is shorter than the length of said adjacent spurs.

49. An intrauterine device as defined in claim 34, wherein each of at least a portion of said spurs has an enlarged bulbous terminal portion.

50. A device as defined in claim 34, made from a plasticmaterial comprising an ethylene vinyl copolymer.

51. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; a plurality of short spurs extending outwardly from each of said side portions; thin webs integral with the outer edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said outwardly extending short spurs, each of at least some of said thin webs integral with the outer edge protrude outwardly from said perimetral portion a distance greater than the length of said adjacent spurs.

52. An intrauterine device as defined in claim 51, wherein said protruding thin webs are disposed between all adjacent pairs of short spurs on each of said side portions.

53. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; a plurality of short spurs extending outwardly from each of said side portions; and a plurality of rows of short spurs are disposed on and extend inwardly from said perimetral portion, including plural rows on at least each of said two side portions.

54. An intrauterine device as defined in claim 53, wherein the spurs in all of said rows on each of said side portions are side by side in a direction normal to the general planar shape of the device.

55. An intrauterine device as defined in claim 53, wherein the spurs in one of the adjacent rows on each side of said side portions are offset from the spurs in another of said adjacent rows on the same side of said side portion in a direction along the perimetral portion.

56. An intrauterine device as defined in claim 53, wherein thin webs integral with saidperimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs on each of said side portions.

57. An intrauterine device as defined in claim 56, wherein said thin webs are disposed between all adjacent pairs of short spurs in a row on each of said side portions.

58. An intrauterine device as defined in claim 56, wherein at least some of said thin webs are shorter than the length of said adjacent spurs.

59. An intrauterine device as defined in claim 56, wherein at least some of said thin webs protrude outwardly from said perimetral portion a distance greater than the length of said adjacent spurs.

60. An intrauterine device as defined in claim 53, wherein said central body includes a perimetral rim with thin membrane means across the area circumscribed by said perimetral rim.

'61. An intrauterine device asdefined in claim 60, wherein said membrane means is connected to said perimetral portion by a plurality of bridge portions and provides openings at least adjacent said nose portion and said tail portion.

62. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, a plurality of spaced apart short rod-like spurs extending inwardly from each side portion of said perimetral portion, and thin webs integral with the edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs, each of said thin webs between adja cent spurs being attached only to said edge of said perimetral portion and disposed loose between said adja cent spurs.

63. An intrauterine contraceptive device made from material enabling flexing to conforn to the uterine cavity comprising: a central body having a perimetral portion with nose tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, a plurality of spaced apart short spurs extending inwardly from said perimetral portion, thin membrane means connected to said rim portion and extending across the area circumscribed by said perimetral rim portion, and thin webs integral with the edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs, each of said thin webs between adjacent spurs being attached only to said edge of said perimetral portion and disposed loose between said adjacent spurs.

64. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; a plurality of short spurs extending outwardly from each of said side portions; thin webs integral with the outer edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said outwardly extending short spurs, each of at least some of said thin webs between adjacent spurs being attached only to said edge of said perimetral portion and disposed loose between said adjacent spurs.

65. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; a plurality of short spurs extending outwardly from each of said side portions; thin webs integral with said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs on each of said side portions, each of said thin webs between adjacent spurs being attached only to said edge of said perimetral portion and disposed loose between said adjacent spurs; and said central body including a perimetral rim with thin membrane means across the area circumscribed by said perimetral rim.

66. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart short spurs extending inwardly from said perimetral portion; a plurality of short spurs extending outwardly from each of said side portions; thin webs integral with said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs on each of said side portions each of at least some of said thin webs are integral with the outer edge and protrude outwardly from said perimetral portion a distance greater than the length of said adjacent spurs; and said central body including a perimetral rim with thin membrane means across the area circumscribed by said perimetral rim.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,835,350 Dated September 17, 1974 Inventor(s) Irwin ner It is certified that error appears in the aboveidentified patent and that said Letters Patent are hereby corrected as shown below:

Column line 15, change "rail" to -tail.

Column line 32, change "For" to --for- Col umn 2 line 54, change- "or" (first occurrence) to Column line 10, after "20" insert t0-.'

Column l4, line 3 (claim 28, line 6), after "apart" insert --short-- On the cover. sheet Column 1, line 15," change "Aolto" to' -A.H.;

Signed and sealed this 31st day of December 1974.

(SEAL) Attest:

I-IcCOY II. GIBSON vJR. I C. T-lARSHALL DAN-l Attesting Officer Commissioner of Patents DRM po'wso H0439) USCOMM-DC mam-won 79 U S. GOVERNMUH' PRINHN 1'

Claims

1. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, and a plurality of spaced apart short rod-like spurs extending inwardly from each side portion of said perimetral portion.

17. An intrauterine device as definEd in claim 16, wherein each of said thin webs between adjacent spurs in a row is attached only to said perimetral portion and is disposed loose between said adjacent spurs.

19. An intrauterine device as defined in claim 18, wherein said shorter thin webs are disposed between all adjacent pairs of short spurs on each of said side portions.

27. A device as defined in claim 26, made from a plastic material comprising an ethylene vinyl copolymer.

28. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral rim portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity; a plurality of spaced apart spurs extending inwardly from said perimetral portion; and thin membrane means connected to said rim portion and extending across the area circumscribed by said perimetral rim portion.

41. An intrauterine device as defined in claim 40, wherein said membrane means is connected to both side portions and provides openings adjacent said nose portion and said tail portion.

48. An intrauterine device as defined in claim 45, wherein each of at least some of said thin webs is shorter than the length of said adjacent spurs.

50. A device as defined in claim 34, made from a plastic material comprising an ethylene vinyl copolymer.

56. An intrauterine device as defined in claim 53, wherein thin webs integral with said perimetral portion are disposed on each side portion between at least two adjacent ones of said short spurs on each of said side portions.

61. An intrauterine device as defined in claim 60, wherein said membrane means is connected to said perimetral portion by a plurality of bridge portions and provides openings at least adjacent said nose portion and said tail portion.

62. An intrauterine contraceptive device made from material enabling flexing to conform to the uterine cavity comprising: a central body having a perimetral portion with nose, tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, a plurality of spaced apart short rod-like spurs extending inwardly from each side portion of said perimetral portion, and thin webs integral with the edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs, each of said thin webs between adjacent spurs being attached only to said edge of said perimetral portion and disposed loose between said adjacent spurs.

63. An intrauterine contraceptive device made from material enabling flexing to confom to the uterine cavity comprising: a central body having a perimetral portion with nose tail and side portions and encompassing an area approximating that of an average normal condition uterine cavity, a plurality of spaced apart short spurs extending inwardly from said perimetral portion, thin membrane means connected to said rim portion and extending across the area circumscribed by said perimetral rim portion, and thin webs integral with the edge of said perimetral portion disposed on each side portion between at least two adjacent ones of said short spurs, each of said thin webs between adjacent spurs being attached only to said edge of said perimetral portion and disposed loose between said adjacent spurs.