Diagnosis of multiple pregnancies presents certain difficulties, especially in the first half of pregnancy, when multiple pregnancy can be suspected only by the rapid increase in the size of the uterus, does not coincide with the period of delay in menstruation.
In the early stages of pregnancy, in a larger number of women with two fetuses, the size of the uterus does not differ from that in single pregnancy. Starting with the second trimester of pregnancy, the size of the uterus in a woman with twins becomes larger. In the presence of twins, as early as 16-20 weeks of gestation, VSDM is significantly larger (by 2-3 cm) than in single pregnancy.
In the future (from 16 to 28 weeks), there is also a progressive increase in HDM, the difference is 4-6 cm (compared with single pregnancy). The rate of growth of VSDM in this period is 1.5-2 cm in 1 week. After 28 weeks of pregnancy, the rate of increase in VSDM decreases, and from 35 weeks of pregnancy it increases again.
In later terms of pregnancy, the increase in the size of the uterus also outstrips the gestational age. The height of the standing of the bottom of the uterus often exceeds 40cm, the abdominal circumference - more than 100cm. It is possible to define indentations along the anterior wall of the uterus in the longitudinal or transverse direction, depending on the position of the fetuses in the uterus. It is necessary to pay attention to the presence of a small pre-existing part of the fetus by a significant amount of the pregnant uterus.
Important is palpation in the uterus in the midwifery study of three or more large parts of the fruit, a relatively small pre-existing part with a significant increase in the uterus, a large number of small parts in various parts of the abdomen, a feeling of fetal movements in different places. In case of multiple pregnancy, you can hear the heartbeat of fetuses in different parts of the uterus, which has a different frequency (the difference is not less than 10 beats per minute). This sign is of particular importance, when between listening to the heartbeat is the zone of its absence.
Significant signs of the presence of multiple pregnancies are data from ultrasound and phono-electrocardiography studies, with which you can register the vital functions of two or more fruits.
When a multiple pregnancy is detected, it is necessary to diagnose the positions of the fetuses in the uterus and, most importantly, the position of the fetus that will be born first. It is known that in 90% of twins both fetuses are in the longitudinal position: both in the main, or one in the main, and the second - in the pelvic presentation. Very rarely the fruits are located in the uterus transversely.