Mature pregnancy

The transferred pregnancy belongs to the category of problems traditionally determining the great scientific and practical interest, caused, first of all, by unfavorable perinatal outcomes in this pathology.

In the domestic obstetrics believe that a delayed pregnancy, lasting more than 287-290 days, is accompanied by intrauterine fetal suffering and ends with the birth of a child with signs of biological ripeness, which determines the high risk of an ante / intrapartum distress syndrome and hampered neonatal adaptation.

[1], [2], [3], [4], [5], [6]

Epidemiology

The frequency of a postponed pregnancy in Russia ranges from 1.4 to 16% (an average of 8-10%) and does not tend to decrease.

The American Association of Obstetricians and Gynecologists refers to a pregnant woman who continues for more than 42 weeks (294 days). Its frequency averages about 10%. In most European countries, a delayed pregnancy is said if it lasts 294 days or more, except for Portugal (287 days or more) and Ireland (292 days or more). The frequency of a pregnant pregnancy in Europe is about 3.5-5.92%.

At the same time, not always with a pregnant pregnancy a child with signs of overripeness is born and, on the contrary, signs of transferability can be noted in a fetus born before the expiration of 290 days of gestation, which is probably due to the individual terms and features of the development of pregnancy. However, the functional state of an overripe fetus deserves more attention, given the greater incidence of serious complications such as the syndrome of meconial aspiration, hypoxic-ischemic involvement of the central nervous system, myocardium, kidneys, and intestines, leading to ante- and intranatal death of the fetus.

A pregnant pregnancy is attributed to factors that affect the increase in the incidence of complications of labor, and also leads to an increase in the rates of perinatal morbidity and mortality. The most characteristic perinatal complications of a pregnant pregnancy are stillbirth, asphyxia and birth trauma. E.Ya. Karaganova, I.A. Oreshkova (2003), after a careful analysis of perinatal outcomes in 499 patients with a pregnant pregnancy, depending on the gestation period, found that as the pregnancy period increased from 41 to 43 weeks, the proportion of perinatal morbidity increased. Thus, at the gestational age of 43 weeks, the frequency of hypoxic-ischemic involvement of the central nervous system increases by 2.9 times, asphyxia by 1.5 times, and aspiration syndrome by 2.3 times compared with full-term newborns with a gestation period of no more than 41 weeks. At the gestational age of more than 41 weeks, the signs of fetal heart disease before the onset of labor were found in 67.1% of the fetuses (half of them with a gestation period of 42-43 weeks), meconium in the amniotic fluid in 31.6%, 50.9% of patients.

[7], [8], [9], [10], [11], [12], [13], [14], [15], [16], [17]

Risk factors

At the analysis of somatic, obstetric-gynecological anamnesis, features of current pregnancy, risk factors are indicated , indicating the possibility of developing a prolonged and prolonged pregnancy.

Risk factors for a delayed pregnancy:

• the age of a pregnant woman over 30;
• presence of a history of sexually transmitted infections (STIs) and chronic inflammatory diseases of the uterine appendages;
• an indication of late births in an anamnesis;
• "Immature" or "insufficiently mature" cervix for a period of 40 weeks or more of gestation.

Risk Factors for Prolonged Pregnancy:

• age of the pregnant woman from 20 to 30 years;
• abnormal ovarian function with irregular or prolonged (≥35 days) menstrual cycle;
• a discrepancy in the gestational age determined by the 1st day of the last menstruation and ultrasound scan.

[18], [19], [20], [21], [22], [23], [24], [25]

Symptoms of the postpartum pregnancy

For the first time, the symptomatic complex of an overripe fetus was described by Vallantyne (1902) and Runge (1948), which is why it is called the Ballentyne-Runge syndrome, which includes the absence of a damp grease, dryness and maceration of the baby's skin ("bath" feet, hands), and inguinal and axillary folds, long nails, dense skull bones, narrow sutures and reduced fontanel sizes, greenish or yellowish staining of the skin, membranes, umbilical cord. In the remaining observations, they speak of a prolonged pregnancy.

Prolonged pregnancy, lasting more than 287 days, is not accompanied by fetal suffering and ends with the birth of a healthy child without signs of overripe. Thus, the prolonged pregnancy is considered as a physiological condition aimed at the final maturation of the fetus.

Diagnostics of the postpartum pregnancy

The traditional diagnosis of a delayed pregnancy is the adequate calculation of the gestational age. At the same time, calculations based on the 1st day of the last menstruation and on the basis of ultrasound scanning data from 7 to 20 weeks of gestation are included in the most accurate methods at the present stage. A number of authors consider these two methods to be equivalent. However, some researchers in the determination of the gestation period for overdrafting suggest that they rely solely on ultrasound biometry data. Among the risk factors for a delayed pregnancy, a number of features of a somatic, obstetric-gynecological anamnesis and the course of a present pregnancy are distinguished.

From the somatic anamnesis, many authors distinguish the age of parents over 30, the presence of extragenital pathology in the mother. Among the features of obstetric-gynecological history, attention should be paid to the violation of menstrual function, the presence of abortions and spontaneous abortions, inflammatory diseases of the uterine appendages, late births in an anamnesis, for 3 or more upcoming births.

Laboratory diagnosis of a pregnant pregnancy

As the term of the endured pregnancy increases, the kalelekine-kinin system progressively depletes, manifested in an extremely low content of kininogen (0.25-0.2 μg / ml, with N = 0.5 μg / ml), low kallecrein activity, its inhibitors and spontaneous esterase activity of blood plasma after 41 weeks of pregnancy.

With a delayed pregnancy, the intensification of the processes of lipid peroxidation, both in the body of the pregnant woman and in the fetal organism, is observed, which contributes to the inhibition of membrane-binding enzymes of subcellular structures. As a result, detoxification and energy-producing functions are significantly impaired and, as a result, the accumulation of exo- and endogenous toxic metabolites, the development of endotoxemia, progressing as the gestation period increases. The intensity of endotoxemia can be estimated by the sorption capacity of erythrocytes and by the concentration of average molecular proteins. The increase in the parameters of peroxidation and endogenous intoxication correlates with the severity of fetal hypoxia.

For a pregnant pregnancy, a low content of prostaglandin F2α, synthesized in the decidua and myometrium, is the main modulator of the development of labor.

At the gestational age of more than 41 weeks, increase in plasma viscosity, uric acid concentration, as well as a decrease in the concentration of fibrinogen, antithrombin III, and platelet count are noted. Concentration of fetal fibronectin> 5 ng / ml in cervicovaginal secretion in women with a gestation period of more than 41 weeks indicates a high biological readiness of the organism for parturition and their spontaneous onset within the next 3 days. The sensitivity and specificity of this method is 71 and 64%, respectively.

It is extremely important to study the features of the functional state of the fetoplacental complex and fetus in a pregnant pregnancy (ultrasound, dopplerometric and cardiotocography research). In the echographic study, fetometry is performed to determine the estimated weight of the fetus and evaluate its anatomical development. In 12.2% of cases, I-II degree of IHD is detected, which does not differ significantly from the incidence of the syndrome in prolonged pregnancies. At the same time, in 80% of the observations we detected an asymmetric form and in 20% a symmetrical form of the NWFP. For a pregnant pregnancy, it is characteristic to identify echographic signs of pronounced involute-dystrophic changes (GIII with petrification). The average value of the index of the volume of amniotic fluid in the group of the transferred pregnancy was 7.25 ± 1.48, typical for a pregnant pregnancy is the detection of a reduced amount of amniotic fluid.

[26], [27], [28], [29], [30]

Doppler study

The most important for the prognosis of perinatal outcomes is the determination of the stage sequence of fetal hemodynamics disorders in a pregnant pregnancy.

• I stage - violation of intraplacenta and fetoplacental blood flow. At this stage, there is no disturbance of arterial and venous fetal hemodynamics. The increase of vascular resistance in the artery of the umbilical cord and its terminal branches, as well as in the spiral arteries, is noted. The parameters of the gas composition and acid-base state of umbilical cord blood are within normal limits.
• Stage II - centralization of the fetal circulation. In the blood of a newborn at birth, note hypoxemia. At this stage, two consecutive stages are distinguished.
  • IIa - initial signs of centralization of the arterial blood circulation of the fetus with unchanged venous and intracardiac blood flow, characterized by:
    • a decrease in resistance in the AGR (no more than 50%) or an increase in vascular resistance in the aorta;
    • decrease in the CPC (up to 0.9);
    • increased resistance in the fetal renal arteries by no more than 25% of the norm.
  • IIb - moderately expressed centralization of blood circulation with disturbance of blood flow in the venous duct and increase in blood flow velocities on the aortic valve. At this stage, they reveal:
    • simultaneous increase in vascular resistance in the aorta and a decrease in the middle cerebral artery;
    • reduction of the CPC;
    • an increase in the average blood flow velocity (Tamx) in the venous duct;
    • increase in the average linear and volumetric flow velocity of the aortic valve.
• Stage III - marked centralization of fetal circulation with violation of venous outflow and decompensation of central and intracardiac hemodynamics. In the cord blood of a newborn at birth, hypoxemia is noted in combination with acidosis and hypercapnia. Dopplerometric indicators at this stage are characterized by:
  • reduction of vascular resistance in the AGR more than 50% of the norm, a decrease in the CPC below 0.8;
  • progressive increase in vascular resistance in the aorta and renal arteries by more than 80%;
  • in the venous duct - an increase in S / A ratio, PIV (more than 0.78) and a decrease in Tamx;
  • in the inferior vena cava - an increase in DIV, IPN and% R (more than 36.8%);
  • in the jugular veins - an increase in S / A ratio, PIV (above 1.1) and a decrease in Tamx;
  • decrease in the average linear and space velocity on the valves of the aorta and pulmonary trunk;
  • increased heart rate, decreased stroke volume, end-systolic and end-diastolic volumes of the left ventricle, cardiac output.

The selected stages of the fetal hemodynamic changes reflect the progressive progression of violations of its functional state in conditions of chronic intrauterine hypoxia in a pregnant pregnancy. If a newborn hypoxemia is detected in the umbilical cord blood in combination with hyperacidemia and hypercapnia, the incidence of adverse perinatal outcomes is 4.8 times higher than in the group isolated by hypoxemia. Consequently, hyperacidemia and hypercapnia reflect severe disturbances in fetal metabolism and progressive deterioration of its condition in conditions of chronic hypoxia in a pregnant pregnancy.

[31], [32], [33], [34]

Cardiotocography

When this method is performed, the first signs of chronic intrauterine hypoxia (20.93%), moderately expressed fetal hypoxia (6.97%) are revealed at the first stage. At the IIa stage, the frequency of initial signs of fetal hypoxia increased 2-fold, at a moderate-4,13 times. At the IIb stage, the frequency of mild and severe fetal hypoxia significantly increases. At stage III, only severe (65.1%) and moderate (30.2%) fetal hypoxia were identified.

The screening program for pregnant women includes:

• detection of pregnant at-risk group of a pregnant pregnancy;
• ultrasonic fetometry with an evaluation of the signs of maturity of the newborn;
• assessment of the quantity and quality of amniotic fluid;
• assessment of the degree of maturity of the placenta;
• cardiotocography;
• evaluation of hemodynamics of the fetus (middle cerebral artery, aorta, venous duct, inferior vena cava);
• evaluation of the biophysical profile of the fetus;
• assessment of the maturity of the cervix;
• amnioscopy.

[35], [36], [37], [38], [39]

Differential diagnosis

In a comprehensive survey of women with prolonged pregnancy, they reveal:

• in 26.5% of observations - II degree, in 51.8% - III degree of maturity of the placenta;
• in 72,3% of cases - normal quantity of amniotic fluid;
• in 89.2% of observations - the normal indices of the fetoplacental blood flow and in 91.6% the normal cerebroplacental ratio;
• in 100% of observations - normal indices of the central hemodynamics of the fetus, perovlapannogo and venous bloodstream;
• a decrease in the CPC at normal indices of the fetoplacental and fetal blood flow indicates the presence of abnormalities in the functional state of the fetus and is characteristic of FGRS, intrauterine infection, chronic fetal hypoxia.

[40], [41], [42], [43], [44], [45], [46], [47], [48], [49], [50]

Treatment of the postpartum pregnancy

The goals of treatment of a pregnant pregnancy: correction of fetal hemodynamics, prevention of fetal progression in childbirth, preparation of birth canal for childbirth, induction of labor.

Indications for hospitalization

Exceeding the gestation period 40 weeks 3 days at precisely calculated date of birth, the presence of risk factors for a pregnant pregnancy, not enough ready-made birth canal.

Drug treatment for a pregnant woman

To correct the fetal condition with a pregnant pregnancy, the drug gesobendin + etamivan + etofillin (instenon) is used - a combined drug possessing a neuroprotective effect based on mutual potentiation of the effects of its constituent components.

Indications for the introduction of the drug gesobendin + etamivan + etofillin:

• disturbed blood flow in the artery of the umbilical cord of the fetus (SDO> 2.7 IR> 0.65);
• a decrease in the cerebroplacental coefficient (CPV <1.10);
• initial signs of centralization of the fetal circulation;
• initial signs of fetal hypoxia according to CTG. These factors, indicating the initial signs of fetal fetal failure, do not require emergency delivery, but indicate the need for correction of his condition by increasing the adaptive capacity of the fetal brain during the labor act.

[51], [52], [53], [54], [55], [56], [57], [58]

Preparation for childbirth with a delayed pregnancy

Mechanical methods of irritation of the cervix:

• Separation of the lower pole of the fetal bladder. To enhance the synthesis of prostaglandins and "maturation" of the cervix can lead and detachment of the lower pole of the fetal bladder. Conducted daily or 2-3 times a week detachment of the lower pole of the fetal bladder contributes to the preparation of the cervix for labor and the induction of labor. This method is distinguished by high efficiency, ease of implementation, low frequency of side effects and cheapness. Its disadvantages: discomfort, felt pregnant in the study, rarely bleeding and the possibility of rupture of membranes.
• Balloon dilatation of the cervix. For balloon dilatation of the cervix, a Foley catheter balloon is used. It is injected and inflated in the cervical channel. This method mechanically expands the cervical canal and enhances the synthesis of prostaglandins. Through the catheter, it is possible to inject the brine into the extra amniotic space, expanding the lower uterine segment and also contributing to the onset of labor.
• Mechanical dilators of natural and synthetic origin. To prepare the cervix for delivery, cervical dilators of natural origin - laminaria and synthetic - dilapan, hypan, lamicel, representing probes with a diameter of 2 to 4 mm and a length of 60-65 mm are used. Laminaria are made of natural material of algae Laminaria japonicum. Synthetic dilators are created from chemically and biologically inert polymers with good hygroscopicity. Expanding probes are inserted into the cervical canal in the required amount. Due to their hygroscopicity, they absorb the fluid contained in the cervical canal, expand substantially and exert radial pressure on the cervical canal. They mechanically open the cervix and promote the onset of labor. Synthetic dilators of the cervical canal do not cause discomfort and are well tolerated by patients. The limited use of synthetic dilators is associated with the cautiousness caused by their prolonged stay in the cervical canal, which increases the risk of developing an ascending infection. The described mechanical methods of action on the cervix cause a reaction of synthesis of endogenous prostaglandins E2 in the cervix, which help to reduce the amount and destabilization of collagen in its structure, which have a relaxing effect on smooth muscles. In addition, prostaglandins E2 are classified as dominant at the beginning of the birth act.

Medications

They use preparations of the prostaglandin group E2. To the most common, approved in practical obstetrics, drug preparations for the cervix for delivery and induction are products of prostaglandins E2. Prostaglandins E2 are released in various dosage forms: in the form of gels for intracervical application, vaginal tablets and pessaries. Efficacy in the maturation of the cervix and the onset of labor with the use of prostaglandins E2 reaches 80-83%. However, against the background of their use, it is possible to develop discordant, turbulent labor and premature detachment of the normally located placenta. Therefore, the introduction of prostaglandins E2 should be performed only in obstetric hospitals with mandatory cardiotocographic monitoring of fetal cardiac activity and contractile activity of the uterus.

Patient education

Required:

• training a woman to manage the menstrual calendar to ensure that she can accurately count the pregnancy and calculate the date of birth; calculation of fetal movements for the timely determination of the risk of fetal hypoxia with a decrease or increase in its motor activity;
• informing the patient about the need for a thorough evaluation of the fetus with a gestation period of more than 40 weeks 3 days and possible hospitalization in the presence of adverse prognostic factors.

Further management

The standard of examination and management of women with a pregnancy period exceeding 40 weeks:

• Carrying out of differential diagnostics of the transferred and prolonged pregnancy.

About a delayed pregnancy should be considered with: the first upcoming birth in a pregnant woman over the age of 30, a regular menstrual cycle, the presence of an anamnesis of STIs and chronic inflammatory diseases of the uterine appendages, an indication of late births, the timing of pregnancy calculated on the 1st day of the last menstruation and data Ultrasound scan performed in the period from 7 to 20 weeks of gestation, if there is an "immature" or "not enough mature" cervix, if the placenta GIII is detected, the degree of maturity, or the lack of hydration with ultrasound.

On the prolonged pregnancy indicates: the age of the pregnant woman from 20 to 30 years; violation of ovarian functions with irregular or prolonged (> 35 days) menstrual cycle; discrepancy of the gestational age determined by the 1st day of the last menstruation and ultrasound scan; identification of the "mature" cervix of the uterus; placenta GI and GIII degree of maturity without petrification and normal amount of amniotic fluid in ultrasound.

• To properly assess the condition of the fetus and prevent adverse perinatal outcomes for all pregnant women with a gestation period of more than 40 weeks, it is necessary to conduct a Doppler study of the arterial hemodynamics of the fetus.
• With unchanged fetal hemodynamics, the organism is prepared for labor with the use of estrogens, intracervical injection of prostaglandin E2 gel with dynamic CTG control (daily) and monitoring of the state of the fetal blood flow (every 3 days).
• If blood circulation is centralized, the study of venous blood flow and intracardiac hemodynamics is indicated to clarify the compensatory possibilities of the fetus and the choice of the method and term of delivery.
• With a delayed pregnancy, the hemodynamics of the fetus varies step by step:

I stage - violations of intraplacental and fetoplacental blood flow. At this stage, there is no disturbance of arterial and venous fetal hemodynamics. The increase of vascular resistance in the artery of the umbilical cord and its terminal branches, as well as in the spiral arteries, is noted. The parameters of the gas composition and acid-base state of umbilical cord blood are within normal limits.

Stage II - centralization of the fetal circulation. In the blood of a newborn at birth, note hypoxemia. At this stage, two consecutive stages should be distinguished:

• IIa - initial signs of centralization of the arterial blood circulation of the fetus with unchanged venous and intracardiac blood flow;
• IIb - moderately expressed centralization of blood circulation with disturbance of blood flow in the venous duct and increase in blood flow velocities on the aortic valve.

Stage III - marked centralization of fetal circulation with violation of venous outflow and decompensation of central and intracardiac hemodynamics. In cord blood of a newborn at birth - hypoxemia in combination with acidosis and hypercapnia.

• If there is a decreased CPC (<1,1), the centralization of the fetal hemodynamics (initial centralization: SDO in SMA <2.80, in Ao> 8.00) with an increase in the average flow velocity in the venous duct (moderately pronounced centralization: SDO in SMA < 2.80, in Ao> 8.00, Tamx in VPr> 32 cm / s), the initial signs of fetal hypoxia according to CTG in terms of prenatal training to enhance the adaptive capacity of the fetal brain showed intravenous administration of the drug gesobendin + etamivan + etofillin.
• At initial centralization (SDO in AGR <2.80, or in fetal aorta> 8.00), with good biological readiness of the organism for childbirth, uncomplicated obstetrics and gynecological history, average fetal size, programmed births through natural birth canals after amniotomy under careful cardiomonitor monitoring of the fetal cardiovascular system. Absence of biological readiness of the organism for childbirth, burdened obstetric-gynecological anamnesis, large size of the fetus dictate the need for delivery by cesarean section in a planned manner.
• With moderately pronounced centralization of the fetal hemodynamics (SDO in CMA <2.80 and in the aorta> 8.00, Tamx in VPP> 32 cm / s), in connection with the intensity of all compensatory mechanisms of the fetus and the lack of reserve capabilities for the generic act, a rhodorase solution by cesarean section operation in a planned manner.
• Detection of abnormalities in both the arterial and venous channel of the fetal blood flow (expressed centralization: SDO in CMA <2.80 and in the aorta> 8.00; in VBR S / A> 2.25, PIV> 1.00; R> 16%, PIV> 1.2) in combination with moderate or severe fetal hypoxia according to CTG-study indicates decompensation of the fetal hemodynamics and requires delivery by cesarean section in emergency.

Prevention

• Isolation of the risk group of a pregnant pregnancy among women who addressed for antenatal care.
• Prevention of placental insufficiency and large fetus.
• Careful calculation of the gestational age and the date of birth, taking into account the date of the last menstrual period (with a regular menstrual cycle) and ultrasound, performed in terms of up to 20 weeks gestation.
• Timely hospitalization of a pregnant woman for the preparation of birthmarks for childbirth and evaluation of the fetus.

[59], [60], [61], [62], [63], [64], [65], [66], [67]

Forecast

With a timely and thorough assessment of the fetus, adequate obstetric tactics, the prognosis is favorable. The indicators of the physical and neuropsychological development of children do not differ from those in uncomplicated timely birth. However, with the development of complications, especially severe fetal hypoxia, birth trauma, and meconial aspiration, the prognosis is less favorable. Perinatal losses are up to 7%, hypoxic-ischemic lesions of the central nervous system - up to 72.1%.

[68], [69], [70], [71]