From Big Medical Encyclopedia

PERENASHIVANY PREGNANCIES — lengthening of pregnancy for 10 — 14 days and more after the estimated term of childbirth.

P.'s frequency., according to various researchers, from 2 to 14% hesitate. Would distinguish true (biological) P. and the prolonged pregnancy, or an imaginary (chronological) perenashivaniye. Prolonged consider pregnancy which continues more than 290 — 294 days and comes to an end with the birth of the full-term functionally mature child (without signs of dead-ripe stage); the expressed changes in a placenta at the same time are not observed.

Understand pregnancy which continues more than 290 — 294 days, comes to an end with the birth of the child with signs of dead-ripe stage as truly postmature: the big weight (weight) and length, dense bones of a skull, narrow seams and small fontanels, the amount of syrovidny lubricant is sharply reduced or it is absent, flabbiness, maceration and desquamation of skin, «bathing» feet and palms, discoloration of skin (green, yellow) in connection with treatment by meconium, the increased density of cartilages of auricles and a nose, increase in length of nails, etc. The weight (weight) of a placenta at postmature pregnancy is increased, its thickness is reduced; as a rule, petrifikata, fatty transformation, green coloring of fetal membranes, a «lean» umbilical cord are defined. Sclerous changes are widespread in a placenta, the maintenance of a glycogen, neutral glikozaminoglikan, functional and active lipids, RNA, a number of oxidation-reduction enzymes is reduced; accumulation in certain sites of a placenta of acid glikozaminoglikan is noted.

Etiology and pathogeny

P. it is necessary to consider as result of interaction of many factors. Main etiol, the moments conducting to true P., are funkts. shifts in c. N of page (decrease in bioelectric activity of a brain), vegetative and endocrine disturbances in an organism of the pregnant woman. At P. ratio distortion between estrogen and gestagena, corticosteroids, gonadotrophins, between potassium ions, calcium, magnesium, etc. is revealed; increase in activity of some enzymes (lactate dehydrogenase) and reduction of products of oksitotichesky substances (oxytocin); decrease in a bioelectric uterine activity; disturbance of exchange processes in myometriums and a placenta.

The known role in P. play the previous disturbances of menstrual function, change in a uterus (inflammatory, dystrophic) reducing its excitable! and sokratitelny activity; changes of pituitary and adrenal system of a fruit, anomaly and malformations of a fruit, hereditary and immunol, factors, biologically active agents (catecholamines, prostaglandins, serotonin, kinina).

Importance in P.'s pathogeny. belongs to a placenta (see). Fetoplacental insufficiency leads to disbolism in an organism of a fruit, a hypoxia. Weakening of hormonal, humoral influences from a fruit promotes emergence of dystrophic changes in a placenta. In turn, disturbances in sintsitiokapil-lyarny membranes of a placenta reduce viability of a fruit and can lead to his death.

The prolonged pregnancy is caused by set of the adaptive reactions promoting approach of a maturity of a fruit in case of delay of developments of bodies and funkts. systems of a fruit.

Clinical signs

true P.'s Signs.: lack of increase of body weight and decrease in turgor of fabrics at the pregnant woman, reduction of a circle of a stomach by 5 — 10 cm, high standing of an uterine fundus, the big sizes of a fruit, strengthening or weakening of its movements, change of frequency and a timbre of its cordial tones. At the prolonged pregnancy from the specified signs only the big sizes of a fruit and high standing of an uterine fundus are noted.

Pregnancy at a perenashivaniye quite often is complicated by late toxicosis, a pre-natal hypoxia and antenatal death of a fruit.

Childbirth (see) at postmature pregnancy often happen complicated (untimely izlity amniotic waters, anomaly of patrimonial activity, etc.) that quite often results in need of an operative measure; the hypoxia of a fruit is noted, raises perinatal mortality (see).

The diagnosis

the Diagnosis is made on the basis of data of the anamnesis, obstetric inspection, laboratory and tool methods of a research. It is important to specify, the true perenashivaniye of pregnancy or prolongation of pregnancy because tactics of conducting pregnancy and childbirth in this or that case shall be various takes place.

For true P., according to FKG and an ECG of a fruit, the following changes of cordial activity are characteristic: monotony of a rhythm, irregularity of tones, big duration and a high voltage of the QRS complex, splitting of a top of a tooth of R, the changed reaction to functional trials or its absence. At the prolonged pregnancy increase in a voltage of the ventricular QRS complex of a fruit, increase in its duration in comparison with these indicators at the full-term pregnancy is noted a nek-swarm.

At ultrasonic investigation (see. Ultrasonic diagnosis, in obstetrics and gynecology ) at women with true P. reduction of thickness of a placenta, a relative oligoamnios, more accurate contours and a thickening of bones of a skull of a fruit, the termination of increase in the biparietal size of a head of a fruit after 40 weeks of pregnancy, the large sizes of a fruit is revealed. At the prolonged pregnancy the sizes of a fruit larger, than at full-term, increase in the biparietal size of a head of a fruit is also noted.

At amnioskopiya (see) characteristic of true P. are: trace amount of the muddy (opalescent) or painted by meconium amniotic waters, a small amount (or absence) flakes of caseous lubricant, is noted the high content (more than 50%) of nuclear-free lipoblasts. The following biochemical, indicators of the amniotic fluid received at is characteristic amniocentesis (see): increase in activity of a lactate dehydrogenase, concentration milk to - you and crude protein, reduction of activity of a thermostable isoenzyme of an alkaline phosphatase, decrease in concentration of glucose.

At true P. content of hormones is changed: level of estrogen, generally for the account is reduced estriol (see) which plays an important role in preparation of a neck of uterus and the lower segment for childbirth; level of progesterone (pregnandiol) is increased (see. Progesterone ), high progesterone - an oestrogenic index. Decrease in cells of a myometrium of maintenance of a glycogen, RNA, activity OVER - diaphorases, succinatedehydrogenases, etc. is noted a nek-swarm; at the prolonged pregnancy clearly the expressed changes in myometriums are not revealed.

On true P. specify results of a cytologic research of a vulval smear — the third and fourth cytotype of a smear is noted (see. Vagina ).

Tactics of conducting pregnancy and childbirth

At duration of gestation more than 41 week is necessary hospitalization.

For definition of tactics of conducting pregnancy and childbirth it is necessary to consider character of a perenashivaniye (true or prolonged), funkts, a condition of a fruit, readiness of a maternal organism for approach of childbirth, a condition of a bag of waters. At establishment of the diagnosis of truly postmature pregnancy active tactics of conducting childbirth is necessary.

Patrimonial activity at true P. can spontaneously arise, but it is required to a thicket rodovozbuzhde-ny. At elderly primapara women, at pelvic presentation, at the big sizes of a fruit and a narrow basin, at women with the burdened obstetric anamnesis (infertility, the complicated course of the previous childbirth, a still birth, etc.), at placental presentation, the wrong provision of a fruit, a hem on a uterus, a pre-natal hypoxia of a fruit quite often resort to to Cesarean section (see).

At the prolonged pregnancy and good shape of a fruit childbirth usually occurs spontaneously. At the same time, if the bag of waters is whole, carry out a wedge, overseeing of the pregnant woman until the end of the 42nd week of pregnancy — carry out an amnioskopiya), phono - and an electrocardiography of a fruit, ultrasonic investigation, if necessary — repeated amniocentesis with a research amniotic: liquids. At an unprepared («unripe») neck of uterus, a large fruit, pelvic presentation along with dynamic observation start creation of a hormonal background by administration of estrogen and to a rodovozbuzhdeniye. At the whole bag of waters and moderate amount of amniotic waters rodo-excitement is carried out, without breaking an integrity of a bag of waters, and at the established patrimonial activity make an early amniotomy. At postmature pregnancy of followed oligoamnios, a nephropathy, it is reasonable to begin a rodovozbuzhdeniye with an amniotomy; in the absence of effect during 2 — 3 hours it is necessary to start a medicamentous rodovozbuzhdeniye. From pharmaceuticals intravenous administration of oxytocin, prostaglandin (Enzaprostum) of F is recommended or E 2 or at the same time both drugs. Purpose of quinine, a prozerin, Carbacholinum is less effective. In labor carry regularly out prevention of a hypoxia of a fruit: enter solution of Sygethinum, 5% solution of hydrosodium carbonate, Galascorbinum, cocarboxylase.

At the birth of the child inspection it is performed together with the pediatrician for confirmation of existence of a perenashivaniye of pregnancy and assessment of a condition of the newborn.

Control an acid-base condition of an organism of the newborn and if necessary carry out his correction by introduction to a vein of an umbilical cord of 5% of solution of hydrosodium carbonate. For the postmature newborn make intensive observation as for the child of group of the increased risk.

Postmature children in connection with their big sizes, frequent hron, a hypoxia and the complicated course of childbirth quite often are exposed to an injury at the time of delivery.


Prevention: correct psychological development of girls, allocation of the women inclined to P. (late approach of menarche, disturbance of a menstrual cycle, extragenital and gynecologic diseases, perenashivany pregnancies in the anamnesis) in risk group, overseeing by them in clinic for women, timely hospitalization.

Bibliography: Obstetric and extragenital pathology, under the editorship of A. P. Nikolaev, page 225, M., 1968; Dobrotina A. F., Darovskaya M. G. and Tretyakova E. V. Some biochemical indicators of an amniotic fluid, Akush, and ginek., No. 7, page 36, 1974; Levin - with about N of JI. JI. Postmature pregnancy, JI., 1969, bibliogr.; Persianinov JI. Page, Ilyin I. V. and To r the expert and B. A. Amnioskopiya's N in akushersko!! practician, M., 1973; I r Kommersant to about in JI. And. and Katsulov At. Prenosena beremennot, Sofia, 1971, bibliogr.; Foetus and placenta, ed. by A. Klopper a. E. Diczfalusy, p. 471, Oxford — Edinburgh, 1969; H u-c h e t J. Liquide amniotique et appreciation de la of maturit£ foetale, Contraception, v. 4, p. 47, 1976; Recent progress in obstetrics and gynecology, ed. by L. S. Persia-ninov and. T. V. Chervakova, p. 145, Prague, 1974; S a 1 i n g E. Das Kind im Bereich der Geburtshilfe, S. 60, Stuttgart, 1966.

E. A. Chernukh.