Hormonal studies in pregnancy. I. Total unconjugated estrogens in maternal peripheral vein, cord vein, and cord artery serum at delivery.

The concentration of unconjugated total estrogens (primarily estrone, estradiol-17beta, and estriol) were measured by rapid radioimmunoassay method in serum samples from maternal peripheral vein, cord vein, and cord artery in normal pregnancies at delivery. The serum concentration of total free estrogens found in cord vein was four to five times higher than in maternal peripheral vein and cord artery. Levels obtained in maternal peripheral vein, cord vein, and cord artery were 47.8+/-1.8, 140.1+/-8.57, 31.8+/-2.15 ng. per millilitre (+/-standard error of the mean), respectively. These values are compared with those reported by others.