Population-based case-control teratogenic study of hydroxyprogesterone treatment during pregnancy.

Hydroxyprogesterone, a synthetic progestin, was used for the treatment of pregnant women with threatened abortion and preterm delivery. Previous studies showed some association between hydroxyprogesterone use during early pregnancy and some specific congenital abnormalities. The population-based large Hungarian data set seemed to be appropriate to check this possible association. The Hungarian Case-Control Surveillance of Congenital Abnormalities between 1980 and 1996 includes 22 843 cases with congenital abnormalities and 38 151 controls without any defect. 318 (1.4%) cases, while 433 (1.1%) controls had mothers with hydroxyprogesterone treatment during pregnancy (adjusted POR with 95% CI: 1.3, 1.1-1.5). However, there was no association between risk for any congenital abnormality group and a higher use of maternal hydroxyprogesterone treatment during the second and third month of gestation. On the other hand hydroxyprogesterone is not effective in the prevention of preterm delivery. In conclusion, there was no detectable risk for congenital abnormalities in the offspring of mothers with hydroxyprogesterone treatment during early pregnancy, however, there is no reasonable indication of this treatment during pregnancy.