[Influence of allylestrenol on hpl serum levels in high-risk pregnancies (author's transl)].

32 patients with high-risk pregnancies were treated with 3 X 5 mg of 17alpha-ally1-17beta-hydroxy-estr-4-ene (allylestrenol, Gestanon) daily. Only those patients entered this study, who had pathological HPL serum levels during two successive control investigations. In addition, cytological analyses of vaginal smears were performed before treatment was started. The patients were treated with allylestrenol until normal HPL levels were recorded, but at least during 14 days. HPL serum levels were estimated every second day through 14 days. Thereafter HPL assays were performed in weekly intervals. Determinations of HPL were done by radioimmunoassay. Analyses of vaginal smears were done weekly. Statistical analysis of HPL serum levels were performed by Student's-t-test. A statistical significant increase of HPL serum levels were registered during allylestrenol therapy. These results suggest that the pregnancy maintaining effect of allylestrenol is at least partly due to a stimulation of placental function. Analyses of vaginal smears indicate a progestational effect of the norsteroid.