Dydrogesterone use during pregnancy: overview of birth defects reported since 1977.

Between 1977 and 2005, 28 cases of potential links between maternal dydrogesterone use during pregnancy and congenital birth defects were reported. The types of defects were very diverse, with no evidence of a pattern of abnormalities. The data do not provide evidence for congenital malformations associated with dydrogesterone use.