Multiple pregnancy is a physical condition of a woman when there are several (two, three, four) developing embryos and later fetuses (from the 11th week of pregnancy) in her uterus.
A woman’s pregnancy lasts on average 280 days or 40 weeks from the date of the last menstruation (obstetric period) and 38 weeks from the date of conception (embryonic period). For multiple pregnancy it is usually shorter, for twins, on average, it is 37 weeks, for triplets – 33 weeks, for quadruplets – 28 weeks accordingly.
In the early stages, the symptoms of multiple pregnancy are no different from those of a normal pregnancy, and it can only be suspected because of the unusually rapid increase in the uterus and the size of the abdomen.
During the second half of pregnancy, signs of multiple pregnancy are:
- a rapid increase in the height and circumference of the abdomen;
- feeling of movement of the fetus at the same time in different places;
- feeling of small parts of the fetus (arms, legs) in different parts of the abdomen;
- discernible by touch three or more large parts of the fetus (head, pelvis);
- the appearance of a furrow (a distinct boundary between the fetuses on the abdomen (anterior abdominal wall);
- palpitations of fetuses in two or more different places of the uterus, the presence of a “zone of silence” between them (areas where the heartbeat is not heard). Also, in case of multiple pregnancy in late periods, women are more likely to suffer from shortness of breath, tachycardia (palpitations), high blood pressure, edema.
Pregnancy is conditionally divided into two periods:
- embryonic – up to the 10th obstetric week. During this period, fertilization, cell division, movement of a fertilized egg from the fallopian tube into the uterus, implantation (attachment of the embryo to the uterine wall), development of embryonic leaves (cotyledon) (building blocks for future organs) and the formation of organs and systems;
- fetal – from the 11th obstetric week before delivery. During this period there is an increase in the size of the fetus, the development and improvement of its organs and systems.
Also, pregnancy is usually divided into trimesters (1, 2, 3), respectively, for three months each (up to 12 weeks, 13 – 28 weeks, 29 – 40 weeks).
During multiple pregnancy, twins can be identical (occur when a fertilized egg is completely divided into two parts and have the same genetic data) or fraternal (implantation (attachment to the uterus wall) of two or more different fertilized eggs occurs).
Multiple pregnancy can occur as a result of two mechanisms:
- ripening and fertilization of two or more eggs at once, and in this case a fraternal pregnancy occurs;
- separation of a fertilized egg (zygote) into two or more parts shortly after fertilization.
Also, multiple pregnancy often occurs with artificial insemination, when several embryos implanted in the uterus to increase the success of the procedure and they take root.
Complications of multiple pregnancy can be as follows:
- pregnancy toxicosis – a complication that usually manifests itself in the first half of pregnancy and may manifest as dyspeptic disorders (nausea, vomiting), drooling, abnormal liver function (hepatosis);
- preeclampsia – a complication of pregnancy, characterized by dysfunction of vital organs and systems, usually occurring after the 20th week of pregnancy. Preeclampsia can be mild, moderate and severe. Manifestation of preeclampsia are increasing blood pressure, edema, excretion of protein in the urine (proteinuria);
- miscarriage – spontaneous abortion up to 37 weeks. Termination of pregnancy before the 20th week is called miscarriage, from 20 to 37 weeks – premature birth. If a woman has had three or more miscarriages, then in this case it is habitual miscarriage;
- threatened miscarriage (threatened miscarriage) – increased tone (tension) of the uterus, the appearance of pulling, cramping pains in the lower abdomen of a pregnant woman. There may also be bloody or heavy transparent discharge from the vagina (bleeding, premature rupture of amniotic fluid). All these symptoms require the immediate hospitalization of a woman;
- the threat of premature birth – the appearance of signs of beginning labor (increasing the tone of the uterus, abdominal pain, labor, discharge of amniotic fluid) in the period from 28 to 37 weeks of pregnancy;
- premature birth – birth of a child from 20 to 37 weeks;
- postponed pregnancy – the birth of a child after a period of 42 weeks or more;
- non-developing (frozen) pregnancy – cessation of the development of the embryo (up to 10 weeks of pregnancy) or the fetus and its death;
- iso serological incompatibility (incompatibility of maternal and fetal blood by Rh factor or blood type, as a result of which the mother’s body begins to produce antibodies (protective substances) that damage the fetus and can cause a missed abortion or miscarriage.