The course and management of multiple pregnancy

The course of multiple pregnancy as compared with single pregnancy differs in number of unfavourable features, as in this case greater requirements are established to the pregnant woman than at single pregnancy.

It depends on the fact that in a maternal organism not only one but two or more fetuses develop. In this connection at multiple pregnancy various complications occur more often (in 70-85 %).

The most often complications at multiple pregnancy are:
- threatened interruption of pregnancy in the II and III trimester;
- anemia during pregnancy (40 — 86.7 %);
- gestoses in the second half of pregnancy (13.2–68.4 %);
- excess of amniotic fluid (in every twentieth woman).

The clinical manifestations of the given complications at multiple pregnancy occur in earlier terms than at single pregnancy. Thus, the "critical terms" of multiple pregnancy, at which the risk of development of threatened interruption is highest, are 18-22 and 31-34 weeks of pregnancy, аnemia — 18-32 weeks, late gestosis — 26-36 weeks, excess of amniotic fluid -18-22 weeks.

One of the most often complications are premature labor observed at multiple pregnancy almost in half of cases. Usually the lesser the pregnancy proceeds, the longer the inability to bear the fetus. The twins, especially at triplets and quadruplets, are born prematurely, with the lowered viability. Nevertheless, both at twins and at triplets, children can be born well developed. In the world literature the cases of survival of twins from quadruplets, quintuplets, sextuplet are described.

In this respect, an extremely large role is played by a correct organization of care and nutrition of twins that can appreciably compensate lacks of development. In 6 % of women the reason of inability to bear the fetus is excess of amniotic fluid that is caused by the development of hemotransfusion syndrome of twins, infection at dichorionic type of placenta. The frequency of premature interruption at multiple pregnancy is also increased due to inherent defects of fetus’ development (5.6-26 %), intrauterine destruction of one of the fetuses (in 2.2-5 % of women).

Moreover, to frequent complications developing at multiple pregnancy, the intrauterine delay of development of fetuses, congenital abnormalities, antenatal fetal death refer.

The essential changes of hemo- and urodynamics in women with multiple pregnancy and also of endocrine status are responsible for more often occurrence of varicosity of the lower extremities and genital organs, development of pyelonephritis.

At multiple pregnancy polyhydramnios (an excessive accumulation of amniotic fluid in an egg cavity) is rather frequently observed, occurring during the 5th-6th month of pregnancy. In some cases the excess of amniotic fluid in one fetal chamber can accompany insufficiency in the other.

Complications connected with multiple pregnancy are dangerous both for fetuses and for mother.

Thus, the significance of treatment-prophylactic work of a prenatal dispensary is great. Its early diagnostics and prenatal prophylaxis is the keystone of success at multiple pregnancy. At term of 27-30 weeks of pregnancy the woman should be hospitalized in maternity home to confirm the diagnosis. On revealing feto-placental insufficiency, dissociation of development of fetuses, hypotrophy of fetuses (or one of them), an appropriate treatment should be provided. For a pregnant woman with multiple pregnancy, hospitalization in the maternity department 2-3 weeks prior to prospective term of delivery is necessary for examination, planning tactics of delivery and preparation for it.

The course and management of delivery. The course of delivery at twins basically does not differ from the course of delivery at one fetus: there is a dilatation of the cervical canal followed by rupture of the bag of waters of the first fetus and at last it is born. In certain period of time, usually in half an hour, there is a rupture of bag of waters of the second fetus and delivery of the second fetus. An afterbirth period comes then.

Thus, the cervical and placental stages are common for both fetuses, but the stage of expulsion proceeds for each of them separately. In rare cases the period of expulsion is also common for the twins that usually results in serious complications in delivery.

Delivery at multiple pregnancy quite often has a complicated course and therefore is considered to be pathological. In 30-40 % of women delivery starts prematurely, in 10-30 % of women discoordination and weakness of labor activity are observed, premature and early rupture of bag of waters happens in 15-30 % of patients, and loss of small parts of fetus and umbilicus occurs in 4-8 % of cases.

The development of weakness of labor pains is connected with overdistension of muscles of uterus and the anterior abdominal wall, decrease of its contractility in connection with presence of two or more placentas, and also with increase of size of one of the placentas, that causes exclusion of significant part of myometrium from contractile activity. Due to development of weakness of labor pains the cervical stage may be prolonged.

The second stage of labor also lengthens at times. That is why after the amniorrhexis (rupture of bag of membranes and discharge of amniotic fluid) in the lower portion of the uterine cavity two large parts are found simultaneously, belonging to different fetuses; for advancement of which the protracted work of uterus is required: one of these large parts must be inserted in the entrance, and second — to step back upwards.

Besides, the process of expulsion of two fetuses requires more time than that of one fetus.

Sometimes after birth of the first fetus, the uterus is contracted not at once, thus creating the conditions for increased mobility of the second fetus and it can take a transverse lying. The transverse and oblique lying of the fetus at multiple pregnancy is encountered 5-10 times more often, breech presentation — 8-10 times more often than at pregnancy with one fetus. All this increases incidence of urgent operative delivery in multiple pregnancy.

One of the common complications of this period is the post term rupture of amniotic membranes of the second fetus, owing to that the period of expulsion is delayed, sometimes for 12 hours or more.

A prolonged second stage of labor represents serious danger to mother (infection) and fetus (asphyxia). One of severe complications of the second stage of labor is separation and expulsion of placenta before delivery of the second fetus. The incidence of this complication achieves 3-7 % of all deliveries at multiple pregnancy. Thus, separation and delivery of the placenta, belonging not only to the first twin, but also to the second one, may occur. It usually depends on rapid reduction of uterus volume and decrease of intrauterine pressure after delivery of the first twin. Uterine bleeding in such case is rather dangerous. If partially or completely separated or expulsed placenta after delivery of the first twin belongs to one-egg twins, or if both placentas are separated and expulsed, or one, belonging to non-delivered twin, the life of the latter can be saved only by immediate extraction of the fetus from the uterine cavity.

A very rare but extremely severe complication of the second stage of labor in multiple pregnancy is the collision of twins. This term means linkage of two large parts of the body, belonging to each fetus, above the pelviс inlet. The reason of collision is usually a relatively small size of large parts of the twins at a normal or wide pelvis. Different combinations of linkage of the twins are possible. More often the subsequent head of the first twin is linked with the presenting head of the second twin. It happens in such cases when the first twin is in breech presentation and the second one in head presentation.

Both twins can get into a dangerous situation in those extremely rare cases, when they lie in common amniotic cavity (monoamniotic twins); and due to absence of septum, the umbilici of both fetuses interlace and on passing of the first twin through the birth canal they tighten. Thus arrested circulation of blood in umbilical vessels causes asphyxia of both or one fetus. In postpartum period an insufficient contractile activity of overdistended uterus is often marked. As a result, a dangerous uterine bleeding often occurs. The bleeding not infrequently occurs in early puerperal period as well because of uterine atony.

The involution of overdistended uterus proceeds more slowly than under physiological conditions. It results in puerperal period in delayed contraction of uterus with long blood discharges from it, and also more frequent occurrence of infectious diseases in the afterbirth period.