Changes in maternal circulation provoked by uterine contractions

The authors investigated changes in blood flow to the lower half of the body of pregnant women in supine and lateral positions toward the end of pregnancy and during uterine contractions. Electroplethysmographic recordings taken to that end from the legs of probands revealed significant decline in blood supply during uterine contractions. The changes recorded were statistically significant. In some cases, no change at all was caused by uterine contraction or positioning. Uterine activity was recorded by intra-uterine pressure registration. With the parturient in lateral position blood flows under review proved to be better than in supine position.