A comparison between the composition of maternal peripheral plasma and plasma collected from the retroplacental compartment at caesarean section. A study on protein and steroid hormones and binding proteins.

In the pregnant uterus unique immunological conditions must prevail. Since compounds of possible fetoplacental origin may modulate the local maternal immunological response, higher concentrations of such compounds in the vicinity of the conceptus might be expected. We have measured the concentrations of several compounds in peripheral and retroplacental plasma, mainly by immunological methods, from women delivered by caesarean section in pregnancy week 38-40. Significantly higher (P less than 0.001) retroplacental concentrations were found for human placental lactogen, prolactin, alpha-fetoprotein, tissue polypeptide antigen, non-conjugated estriol and progesterone. Peripheral plasma levels were significantly higher for cortisol (P less than 0.01), transcortin (P less than 0.001) and sex-hormone binding globulin (P less than 0.002). No difference was found for albumin, alpha 2-macroglobulin, estradiol, placental alkaline phosphatase and human chorionic gonadotrophin. Significant correlations between retroplacental and maternal peripheral plasma levels were found for progesterone, cortisol, estradiol, estriol, transcortin, sex-hormone binding globulin, prolactin, human placental lactogen, human chorionic gonadotrophin, placental alkaline phosphatase, albumin and alpha 2-macroglobulin. There were also significant correlations between estradiol and sex-hormone binding globulin as well as transcortin in peripheral maternal plasma.