Does free androgen index predict subsequent pregnancy outcome in women with recurrent miscarriage?

Background: Several studies have investigated plasma androgen levels in women with recurrent miscarriage (RM) with conflicting results on whether an association between hyperandrogenaemia and RM exists. However, none of these studies included sensitive androgen measurements using a large data set. We therefore investigated the free androgen index (FAI) in a large number of women with RM in order to ascertain whether hyperandrogenaemia is a predictor of subsequent pregnancy outcome.

Methods: We studied 571 women who attended the Recurrent Miscarriage Clinic in Sheffield and presented with >= 3 consecutive miscarriages. Serum levels of total testosterone and sex hormone-binding globulin were measured in the early follicular phase and FAI was then deduced.

Results: The prevalence of hyperandrogenaemia in RM was 11% and in a subsequent pregnancy, the miscarriage rate was significantly higher in the raised FAI group (miscarriage rates of 68% and 40% for FAI > 5 and FAI <= 5 respectively, P = 0.002).

Conclusions: An elevated FAI appears to be a prognostic factor for a subsequent miscarriage in women with RM and is a more significant predictor of subsequent miscarriage than an advanced maternal age (>= 40 years) or a high number (>= 6) of previous miscarriages in this study.