Although at 31 weeks the fetus is still premature, but is more and more ready for birth. If the pregnancy is normal, the weight of the fetus, when it begins 31 weeks - 1500 grams or more, height - about 40 cm.
31 weeks of pregnancy - fetal development
At this time, the pancreas begins to work in the fetus, producing insulin. In the lungs, the surfactant continues to be actively produced, but it is not enough for normal operation. But other signs of prematurity persist. In girls, large labia labia do not cover the small ones, the boys did not descend into the scrotum. The skin is covered with the original fluff, the subcutaneous tissue is small, the nails do not yet cover the nail bed.
Fetal ultrasound at 31 weeks of gestation
The third screening ultrasound is usually performed at 31 - 32 weeks of gestation. By this time, the fetus is usually in the head preposition . If the presentation is gluteal, then a special set of exercises is designed to turn the fetus head down. Since in the breech presentation the birth is more difficult, and soon the fetus will become too large to completely turn over.
The main size of the fetus at 31 weeks:
- BDP (biparietal size of the skull) - 78.4 mm;
- LTE (frontal parietal size of the skull) - 58.8 mm;
- DB (thigh length) - 100 mm;
- SDHK (average diameter of the chest) - 73.5 mm;
- SJ (mean abdomen diameter) - 81.0 mm;
- thickness of the placenta 33.4 mm, while it is uniform, without pathological inclusions;
- height of a column of amniotic fluid in a place free from parts of the fruit - 35 - 70 mm.
All four chambers of the heart, the main vessels and valves are clearly visible from the heart. The heart rate is from 120 to 160 per minute, the rhythm is correct. The structures of the brain are uniform, the width of the lateral ventricles of the brain is not more than 10 mm. All internal organs of the fetus are visible.
During this period, it is also determined whether there is an obtuse of the neck with the umbilical cord and how many times. Fetal movements are active, but the mother herself can determine this - at 31 weeks the fetus moves very actively and the tremors are strong enough so that the mother must have at least 10 to 15 movements per hour.