Changes of maternal ACTH and oxytocinase plasma concentrations during the first trimester of spontaneous abortion

The labor at term finishes normal pregnancy. Both labor at term and first trimester spontaneous abortion are connected with increasing cytotoxic immune response within decidua. Th1 cytokines including IL-2 and INF-gamma are able to exert an effect on HPA axis and result in ACTH secretion. Oxytocinase serum level during pregnancy rises with the fetal development and arrest of oxytocinase serum growth might indicate the its development impairment, what might result in spontaneous abortion.

The study group consisted of 27 patients with clinical symptoms of missed abortion. A control group consisted of 89 pregnant women, who were successfully treated because of infertility. Immunoassay was used to measure ACTH plasma concentration. Oxytocinase plasma activity was established using l-cystine-di-beta-naphthylamide as a substrate.

In the present study, significant increase in ACTH plasma concentration was observed during first trimester of spontaneous abortion. These patients were not characterized by significant increase of oxytocinase plasma level.

The observed ACTH rise during spontaneous abortion might be also related to the alterations at the maternal-fetal interface and the response of HPA axis to the growing cytotoxic activity.