Progesterone therapy: Benefit versus risk

In a recent issue Resseguie et al., and in this issue Rock et al., have reported the incidence of congenital malformations in a total of 1081 pregnancies supported with a synthetic or natural C-21 progesterone (P) compound. Neither of these studies provides any support for the concept that these hormones cause major anomalies when given to pregnant women. In this regard, the reports are reassuring and may provide the impetus for the initiation and maintenance of a national registry on this problem.