RU2193198C2 - Method for choosing the tactics of delivery - Google Patents

Abstract

FIELD: medicine, obstetrics. SUBSTANCE: metabolites of nitrogen oxide - nitrites and nitrates are determined in amniotic fluid in pregnant women of risk groups and if their content is 0.62 mcg/ml and higher the delivery should be carried out by Caesarean operation, if their content is below 0.62 mcg/ml the delivery runs through natural parturient canal. The method has no contraindications. EFFECT: higher accuracy of the choice. 3 ex, 1 tbl

Description

 The invention relates to medicine, namely to obstetrics, and will find wide application for an objective choice of labor management tactics.

 It is known that childbirth is a complex physiological process during which the contents of the uterus (fetus, amniotic fluid, placenta and fetal membranes) are expelled. It is accomplished through the interaction of labor forces with the object of childbirth - the fetus - during its passage through the birth canal (E.A. Friedmann, 1967; Savitsky G.A., Moryak M.G., 1983; F. Arkas, 1989; I. V. Duda, V.I. Duda, 1992). The mechanisms of regulation of labor are multilevel in nature and damage to any of them leads to anomalies of labor.

 Violation of the integration between the triggers of labor and the state of the target organ (readiness of the uterus for childbirth) can lead to the development of weakness of labor (E.T. Mikhailenko, 1988), the frequency of which, according to the literature, ranges from 2 to 20%. Pregnant women with late gestosis, cardiovascular diseases, diabetes mellitus, and kidney pathologies can be classified as a risk group for the threat of development of labor weakness.

 Measures aimed at the prevention and treatment of labor weakness do not always turn out to be effective, and the uterus does not respond to drug exposure. In the case of deep violations in the biomechanism of childbirth, they have to end with a caesarean section. The solution to the issue of abdominal delivery should not be belated, as this sharply worsens the outcome of the birth for the mother and the fetus.

 At the present stage of obstetrics development, such obstetric situations are considered absolute indicators for cesarean section, in which cesarean section must be performed in order not only to save the mother’s life, but also to prevent her disability. Relative indicators are those in which a cesarean section (compared with delivery through the natural birth canal) improves the outcome of pregnancy and childbirth for the mother and fetus (A.S. Blind, 1986; E.A. Chernukha, L.M. Komissarova, 1986 )

 If the presence of absolute indications does not raise any doubts about the need for an operative delivery, then relative indications, especially the weakness of labor, require the development of clear criteria for choosing the optimal delivery tactics.

 An analysis of the patent literature allowed us to establish that in order to decide on the choice of delivery tactics, only anatomical signs are used, for example, the ratio of the true conjugates of the small pelvis and the biparetal size of the fetal head (Method of birth, patent 2012218, O. B. 9, 1994), carry out radiographic determining the area of entry into the pelvis, the index of its relation to the mass of the fetus, the direct diameter of the wide part of the cavity and the interosseous diameter (Method for determining the indications for cesarean section in pregnant women with transverse nym pelvis, AS 1627116, OB 6, 1991). At the same time, possible metabolic disturbances in the process of labor excitation remain unaccounted for. Other authors limit the proposed methods of birth management and predicting the outcome of pregnancy to a particular pathology of a woman, for example, the rheumatic process (Method of delivering with rheumatic defects, application 96122217/14, 1999) or threatening miscarriage (Method of predicting pregnancy outcome in women with threatened miscarriage, patent 2033607 O.B. 11, 1995).

 The choice of tactics of delivery, described in the abstract of the dissertation doctorate, was chosen as the prototype of our proposed method. medical science E.N. Zarubina, 1995

 The essence of the prototype method is that 9 clinical and laboratory criteria (on the eve of childbirth) that determine the subsequent choice of the delivery method (maternal age, cardiotocographic monitoring indicators, complications of a real pregnancy) are evaluated for choosing delivery tactics: OPH gestosis, threatened abortion, extragenital pathology, fetal malnutrition and the first degree of placental maturity according to ultrasound, platelet aggregation and cortisol in the mother’s blood). All of the above signs are scored, the higher the total score (S), the higher the perinatal risk. For S> 12, a planned caesarean section is recommended.

This method has several disadvantages:
1) the complexity of the method: for its implementation requires several biophysical and biochemical research methods;
2) the method does not exclude a certain proportion of subjectivity in the measurement of ultrasonic parameters;
3) CTG prognostic data do not always find subsequent confirmation (CL Lowery et al., 1990; E.A. Lyashchenko, 1995);
4) the level of cortisol in the blood of women does not always reflect the compensatory ability of the fetus to withstand birth stress (E. Ohana et al., 1996);
5) increased platelet aggregation is observed in various pathological conditions that are not associated with the need for surgical delivery (N.S. Baksheev, R.S. Orlov, 1976).

 These disadvantages can be eliminated in the claimed invention.

The objective of the invention: simplification, increasing the accuracy and accessibility for widespread use of the method of choosing the tactics of delivery during pregnancy, high risk, which allows you to objectively assess the possibility of delivery through the natural birth canal or to establish the need for abdominal intervention. The problem is solved by the fact that on the eve of childbirth, amniotic fluid is taken from the pregnant woman by amniotomy or when they leak and nitrate oxide metabolites are determined in them by the level of nitrates and nitrites, indicated in the literature NO _x (H. Nanno, N. Sagawa, H.Iton et al., 1998). At a level of NO _x 0.62 μg / ml and higher, delivery is performed by cesarean section, and with a content of NO _x below 0.62 μg / ml, delivery is via the birth canal. The prerequisites for the selection of these signs were the establishment in recent years of the important role of nitric oxide in the regulation of various physiological and biochemical processes, and especially in the regulation of vascular tone, the release of vasoactive mediators from endothelial cells (A.F. Vanin, 1998; J.-K. Stokle and et al., 1998). In recent years, a large number of works have appeared on the diagnostic value of NO in various pathological conditions, however, we have not found studies of the content of nitric oxide metabolites to solve the question of the choice of delivery tactics in the scientific and patent literature. The results of our NO _x study in the amniotic fluid of women with high-risk pregnancy (late gestosis, habitual miscarriage, diabetes mellitus, fetoplacental insufficiency) indicate that with an average NO _x content of 1.34 ± 0.27 μg / ml (individual indicators from 0.62 to 1.90 mcg / ml), they developed persistent weakness of labor. Under normal labor, the level of NO _x was 2.4 times lower and amounted to 0.56 ± 0.097 μg / ml (0.52 - 0.61 μg / ml).

Thus, our data show a clear relationship between the level of NO _x and the nature of labor. The revealed differences are obviously due to a change in the blood supply to the uterus and its contractile activity under conditions of an increase in the content of nitric oxide and an increase in its vasodilator action.

 Example 1. B-naya St., re-pregnant, primiparous, case history 4568/280, 23 years old, was admitted to the maternity department of the Research Institute of Obstetrics and Pediatrics 03.03.99, with complaints of leakage of amniotic fluid.

 Diagnosis: Pregnancy 37-38 weeks, burdened obstetric history, habitual miscarriage, FGN, late gestosis (EN), leakage of amniotic fluid.

 With vaginal examination: the cervix is centered, 1 cm long, softened throughout, cervical dilatation 3 cm, light amniotic fluid in moderation is leaking. The fetal head is pressed to the entrance to the small pelvis. Generic activity is absent. In a bimanual study, the longitudinal position of the fetus, the anterior view, 1 position is determined.

 The patient underwent an ultrasound examination to clarify the gestational age, determine the degree of maturity of the placenta and the condition of the fetus, as well as the amount of amniotic fluid. According to ultrasound, it was revealed that the fetus corresponds to a full-term pregnancy, a placenta of the III degree of maturity. Cardiotocography of the fetus was performed. No pronounced signs of fetal hypoxia were detected. Normocardia - 140 beats / min. According to the currentogram signs of labor activity are not detected.

In order to choose the delivery tactics, amniotic fluid was also studied to determine the content of nitric oxide (NO) by the amount of its metabolites (NO ₂ and NO ₃ ) using the Griss reaction. For this, 1 ml of amniotic fluid is added 1 ml of a 10% solution of trichloroacetic acid, centrifuged for 10 minutes in a refrigerator centrifuge at 3000 rpm, (t - +60 ^o С), 1 ml of centrifugate is taken and 1 ml of commercial Griss reagent (Aldrich is added) Chemical CO, USA). After 10 minutes, the optical density of this sample was measured at 530 nm in a cuvette with a 1 cm layer thickness on an SF-24 spectrophotometer (Russia) against the control, which was a sample treated in a similar way, but containing distilled water instead of amniotic fluid. The content of NO _{x is} calculated according to a pre-built calibration schedule. The results are expressed in μg NO _x per 1 ml of amniotic fluid.

The level of NO _x was 1.2 μg / ml (normal values were 0.52-0.61 μg / ml).

 The results obtained allow us to conclude that the pregnant woman has no labor. It was decided to end the birth operatively.

 March 4, 1999 - a cesarean section was performed in the lower uterine segment, a live, full-term male baby was weighed, weighing 3100 g, 50 cm long, with an Apgar score of 8–9 points.

 Example 2. B-naya M-na, re-pregnant, primiparous, medical history 4936/355, 25 years old, was admitted to the maternity department of the Research Institute of Obstetrics and Pediatrics 04/04/99, with complaints of pain in the lower abdomen, in the lumbar region, 2 5 hours ago. The interval between contractions at the time of receipt of 15-20 minutes, duration 10-15 seconds.

 Diagnosis: Pregnancy 39-40 weeks, burdened obstetric history, FPI, obesity II degree, large fetus, 1 period of childbirth.

 In order to clarify the obstetric situation, a vaginal examination was performed, in which it was established: the cervix is centered, 1.5 cm long, softened, cervical dilatation 3 cm, the fetal bladder is intact, functioning. The fetal head above the entrance to the pelvis. In a bimanual study, the longitudinal position of the fetus, the anterior view, 2 position is determined.

 Cardiotocography of the fetus was performed. No pronounced signs of fetal hypoxia were detected. Normocardia - 138 bpm. According to the currentogram signs of labor are noted.

On April 23, 1999, an amniotomy was performed for the purpose of labor stimulation, a moderate amount of clear amniotic fluid was poured out. Oxytocin stimulation was started according to the generally accepted scheme. With repeated vaginal examination, the status is the same. In the amniotic fluid, the content of NO _x was determined, which amounted to 0.62 μg / ml, which indicates its increased level relative to physiological values, and therefore, an unfavorable prognosis of management of labor through the natural birth canal.

 The results obtained allow us to conclude that a pregnant woman is diagnosed with weak labor. Given the inefficiency of the stimulation, the lack of positive dynamics on the part of the cervix, it was decided to end the delivery by surgery (cesarean section).

 04/23/99, a cesarean section was performed in the lower uterine segment, a live, full-term male baby was weighed, weighing 3950 g, 53 cm long, with an Apgar score of 8–9 points.

 Example 3. B-naya B-va, medical history 5111/451, pre-pregnant, primiparous, 22 years old, was admitted to the maternity department of the Research Institute of Obstetrics and Pediatrics on 06/13/99 for planned delivery.

 Diagnosis: Pregnancy 39-40 weeks, pelvic presentation of the fetus.

 In order to clarify the obstetric situation at admission, a vaginal examination was performed: the cervix is centered, 1 cm long, softened throughout, dilatation 2.5 cm, the fetal bladder is intact, does not function. The pelvic end of the fetus at the entrance to the pelvis. Generic activity is absent. In a bimanual study, the longitudinal position of the fetus, pelvic presentation, and the fetal head on the left at the bottom of the uterus are determined.

 According to ultrasound, the fetus corresponds to the gestational age, the placenta along the front wall of the uterus on the right corresponds to the II-III degree of maturity.

 Cardiotocography of the fetus was performed. No pronounced signs of fetal hypoxia were detected. Normocardia - 144 bpm. According to the currentogram signs of labor activity are not detected.

 In order to choose the delivery tactics, amniotic fluid obtained by amniotomy was examined. Metabolites of nitric oxide were determined, the content of which was 0.61 μg / ml, which indicated the possibility of the development of labor.

 The dynamics of the opening of the cervix and the advancement of the pelvic end through the birth canal were adequate and corresponded to the period of labor.

 The pregnant woman began regular contractions, ending with the birth of a healthy child. A lively, full-term female child was born, weighing 3250 g, 49 cm long, with an Apgar score of 8–9 points.

Thus, the given clinical observations indicate that the determination of NO _x in the amniotic fluid allows us to predict the nature of labor and to implement the optimal method of delivery.

According to the claimed method, 59 pregnant women were examined, 17 of them had late gestosis, 12 had a threat of termination of pregnancy, 7 had diabetes mellitus, 18 had fetoplacental insufficiency, 5 had a history of premature birth. Of the examined contingent of pregnant women, the content of NO _x in the amniotic fluid above 0.62 μg / ml (0.62-1.90 μg / ml) was observed in 27 patients (group 1). All of these pregnant women did not have labor, which served as the basis for deciding on the delivery of labor in an operative way. In 32 examined patients (group 2), the content of NO _x in the amniotic fluid was below 0.62. The timely development of labor activity in them - regular contractions that began after amniotomy - confirmed the diagnostic value of the claimed method.

The results of the study, shown in the table, showed that there is a statistically significant difference in the NO _x level of amniotic fluid between the two groups. Moreover, these indicators are in non-overlapping diagnostic intervals. The accuracy of the method is 100%.

Thus, the claimed method is more efficient compared to the known and has several advantages:
provides high accuracy of the choice of delivery tactics;
objective and simple to implement;
has no contraindications.

 The method was tested on a significant volume of clinical material and can be widely used in maternity hospitals.

Claims (1)

 A method for choosing delivery tactics, which provides for clinical and laboratory tests, characterized in that nitric oxide metabolites — nitrites and nitrates — are determined in the amniotic fluid of pregnant risk groups on the eve of childbirth and, with their content of 0.62 μg / ml and higher, delivery is performed by cesarean section and when the content is below 0.62 μg / ml, delivery is carried out through the natural birth canal.

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