Uterine blood flow, oxygen consumption, and maternal plasma estradiol and progestins following fetal death.

Fetuses of 42 near-term sheep were killed while they were in utero. Uterine blood flow, oxygen consumption, A-V O2, and maternal arterial plasma concentrations of estradiol and progestins were observed for the next 4 hours. There was an immediate (88 per cent) fall in oxygen consumption; blood flow decreased by 50 per cent within 30 minutes. Hormone concentrations changed, but only after 2 hours. Circulatory changes appeared to be related to local changes within the uterus, particularly to decomposition of the chorioallantoic membrane. This relationship was best seen in the experiments in which one of a set of twins was killed. The experiments are in accord with the theory that the rate of uterine blood is not directly related to acute changes in respiratory gases nor to plasma concentrations of certain hormones.