US3431905A

US3431905A - Intrauterine contraceptive device

Info

Publication number: US3431905A
Application number: US551316A
Authority: US
Inventors: Hugh J Davis; Edmund A Jones
Original assignee: Johns Hopkins University; Ortho Pharmaceutical Corp
Current assignee: Johns Hopkins University; Ortho Pharmaceutical Corp
Priority date: 1966-05-19
Filing date: 1966-05-19
Publication date: 1969-03-11
Anticipated expiration: 1986-03-11

Description

March 11, 1969 H. J. DAVIS ET AL 3,431,905

INTRAUTERINE CONTRACEPTIVE DEVICE Filed May 19. 1966 INVENTORSI ATTORNE Y.

United States Patent Claims ABSTRACT OF THE DISCLOSURE An intrauterine contraceptive device formed of a strand of flexible plastic material and having a closed perimeter and an open central area, the device generally conforming to the internal shape of the uterus and having an upper portion and a lower portion, the upper portion consisting of two arms joined at an upwardly extending apex and the lower portion likewise consisting of two arms joined at a downwardly extending apex, each of the arms of the upper portion being joined to an arm of the lower portion to form a side vertex. When the device is in place in the uterus, downwardly directed pressure from the fundus causes the device to expand in a frontal plane, thus increasing the resistance of the device to expulsion.

The present invention relates to an intrauterine contraceptive device, and more particularly, to an intrauterine contraceptive device which conforms substantially to the internal configuration of the uterus.

In recent years, there has been growing enthusiasm for the use of intrauterine contraception, since it is a birth control method which requires but a single visit to a doctor for the fitting of a device by which permanent, reversable contraception is accomplished.

In modern times, intrauterine devices received their impetus from the work of Dr. Grafenberg. The Grafenberg ring was a metal ring, usually of silver, which was inserted into the uterus. Due to its rigidity, the Grafenberg ring could only be inserted by dilating the cervix, a technique which required anesthetizing the patient because of trauma. More recently, modifications of the Grafenberg ring have been used, namely the Ota ring and the Hall-Stone ring, both of which are substantially rigid devices. As with the Grafenberg ring, these devices also require the dilation of the cervix.

In order to overcome the necessity for the dilation of the cervix, Dr. Lazar Margulies invented an intrauterine contraceptive device which can be inserted through an undilated cervix. The Margulies device is the subject matter of United States Patent No. 3,200,815. The Margulies device is coil-shaped and has two free ends. The device can be deformed to a straight line for insertion through the undilated cervix. Upon insertion, the device again assumes its coil shape.

Over a period of five years, the data which has been gathered on the use of intrauterine devices of all types indicates that in a certain percentage of cases, those devices which have free ends may embed themselves in the endomentrial tissue of the uterus, and may actually perforate the uterus.

It has also been observed, that due to the strength of periodic uterine contractions, intrauterine devices of the type having two free ends are often expelled by the uterus.

It is an object of the present invention to provide an intrauterine contraceptive device which may be inserted through a substantially undilated cervix.

It is a further object of the invention to provide an 3,431,905 Patented Mar. 11, 1969 "ice intrauterine contraceptive device which has no free ends.

It is a further object of the invention to provide an intrauterine contraceptive device which resists expulsion.

Referring now to the drawing in which the preferred embodiments of the invention are illustrated:

FIGURE 1 is a plan view of an intrauterine contraceptive device according to the invention.

FIGURE 2 is a cross section of the intrauterine contraceptive device of FIGURE 1 taken through line 2-2.

FIGURE 3 is a frontal section through the uterus showing the placement of the device of FIGURE 1.

FIGURE 4 is a frontal section through the uterus showing a modification of the device of FIGURE 1 in situ.

FIGURE 5 is a perspective view of the device of FIG- URE 1 just prior to its placement into an insertion unit.

FIGURE 6 is a plan view of a modification of the device of FIGURE 1.

The intrauterine contraceptive device of the invention, as illustrated in FIGURE 1 is of a generally diamond shape. The device is formed of a single strand of inert, resilient plastic material, such as polyethylene or Teflon.

The device has two arms of equal length 1 and 2 joined at apex 3 which are joined at

ends

7 and 8 to a second set of two arms of equal length 4 and 5, which are joined at apex 6. The entire device lies in a single plane. The arms 1 and 2 are longer than arms 4 and 5, though a device with arms of equal length may be used. While arms 1 and 2 are preferably bow-shaped, and arms 4 and 5 are preferably arcuate, each of these arms may be straight.

To insert the intrauterine device of the invention into the uterus, the device is inserted into a suitable unit, such as a cannula or insertion forceps by compressing the device at

ends

7 and 8 until it assumes the etxended shape shown in FIGURE 5. Upon insertion in an insertion unit, the device is fully compressed and the inside portions of arms 1 and 2 and arms 4 and 5 are in contact one With the other. The largest cross-sectional dimension of the.

cannula containing the compressed device, being in the transverse plane during insertion, takes advantage of the transversely oval nature of the internal cervical 0s, permitting the insertion of the device without pain or lidation. As seen in FIGURE 3, the cervical opening 30 is slightly wider during insertion that the opening after insertion as seen in FIGURE 4. The walls of the internal cervical os are sufficiently elastic for this widening to occur without pain.

Upon insertion, the device reassumes its original shape as illustrated in FIGURE 4. Due to the configuraton of the device which approximates the internal shape of the uterus, the device is substantially self-positioning upon insertion, tending to rise into the uterine cavity even if inserted by error into the lower uterine segment. Due to its general conformity to the contours of the normal uterine cavity, the possibility of pressure necrosis or embedding into the uterine wall is reduced.

Resistance to expulsion of the device from the uterus is provided by the arms 4 and 5 meeting at an upwardly directed apex 6. The apex 6 rests against the uterine fundus 31. Uterine contractions which tend to expel a foreign body, exert pressure at the fundus 31 against apex 6. This pressure forces arms 4 and 5, and 1 and 2 to open slight- 1y thus reducing the possibility of expulsion of the device.

In order to assist in the insertion of the device, the modification shown in FIGURE 6 has a hinge 19 molded into the apex 16 at which

arms

14 and 15 meet. The molded plastic hinge is more fully described in US. Ser. No. 452,072 filed Apr. 30, 1965.

As an aid to the removal from and for visual confirmation of the presence of the device of the invention in the uterus, a string 31 may be attached to the device at apex 3. Preferably, the string is tied through a hole 9 which passes through apex 3 in order to orient the string along the axis formed by apexes 3 and 9. The string may be of any appropriate inert material, such as a monofilament of nylon or polyethylene, which is allowed to pass through the external os of the cervix as illustrated in FIGURE 4.

What is claimed is:

1. An intrauterine contraceptive device comprising a strand of relatively flexible plastic material forming an essentially closed perimeter and enclosing an open central area,

said device lying essentially in a single frontal plane and having an upper portion and lower portion, said upper portion being defined by a pair of arms of essentially equal length joined at an upwardly directed apex, said lower portion being defined by at least two arms each extending upwardly and outwardly, each arm of said pair of arms of said upper portion being joined to an arm of said lower portion to form an acute side vertex,

said upwardly directed apex being deformable upon the exertion of downward pressure at the top of the same to increase the interior angle of said apex and to thus increase the horizontal distance between said side vertexes,

whereby an intrauterine contraceptive device is provided which when subjected to pressure from the fundus of the uterus expands in the frontal plane to increase the resistance of said device to expulsion.

2. The intrauterine contraceptive device of claim 1 in which said bottom portion consists of a pair of arms of essentially equal length joined at a downwardly directed apex.

3. The intrauterine contraceptive device of claim 2 in which the arms of said upper portion are straight and the arms of said bottom portion are bowed or curved.

4. An intrauterine contraceptive device according to claim 1, wherein said first pair of arms of said upper portion are shorter than said second pair of arms of said lower portion.

5. An intrauterine contraceptive device according to claim 1, wherein said first pair of arms are hingedly joined at said first apex.

References Cited UNITED STATES PATENTS ADELE M. EAGER, Primary Examiner.