Fetal death in utero: Effect on estrone, estradiol-17 ß and progesterone levels in the ewe

Polyvinyl catheters were placed in the maternal femoral artery (MA) and maternal uterine vein (UV) of 11 near-term ewes and in the umbilical vein of their fetuses. 1-5 days postoperatively 100 ml of air were injected into the umbilical vein of 7 fetuses. 4 fetuses served as controls. Samples of blood from MA were taken 15 min prior to air embolism and every 15 min for 3 h, then at +4, +5 and +6 h after air injection. Plasma levels of estrone (E₁), estradiol (E₂) and progesterone (P) were determined by radioimmunoassay. In MA and UV of treated ewes there was a significant decrease in P, but not in E or E₂ after fetal death compared to control ewes. Control levels of P in MA were 9.6 ng/ml; values at +1, +2, +4 and +6 h were 8.8, 3.3, 2.3 and 1.2 ng/ml, respectively.