Maternal serum inhibin A levels are a marker of a viable trophoblast in incomplete and complete miscarriage

Objective: From early gestation the human trophoblast secretes large amounts of inhibin A and activin A, and their measurement provides a value for predicting the outcome in women who become pregnant after assisted reproductive techniques. The aim of the study was to investigate the putative role of maternal serum inhibin A and activin A levels as markers of a viable trophoblast in women who miscarry. Design: Controlled cross-sectional study. Methods: One group consisted of 65 healthy pregnant women (controls), progressing to deliver a healthy singleton baby and another group consisted of 54 miscarriages (38 incomplete (27 nonviable, 11 anembryonic pregnancies) and 16 complete). Maternal blood samples were collected between 5 and 12 weeks of gestation. Results: Serum human chorionic gonadotrophin concentrations in women with incomplete or complete miscarriages were significantly (both P < 0.001) lower than in controls; activin A levels being lowest only in women with a complete miscarriage (P < 0.001). On the other hand, inhibin A levels were significantly lower in incomplete or complete miscarriage than in controls (both P < 0.0001). Conclusions: Maternal serum inhibin A, but not activin A, determination reflects the lack of a viable trophoblast in complete miscarriage.