Genetic counseling for teratogenic risk due to exposure to medications: 89 pregnancies conceived during oral contraceptive use

Congenital malformations are relatively frequent (2% of the general population) but only a small proportion of them can be ascribed to medication exposure during pregnancy. Nevertheless for the purposes of accurate prenatal diagnosis monitoring and research is it important to offer teratology counseling to patients exposed to drugs. There are approximately 20 medications currently on the market that have been universally acknowledged as teratogenic. At the current state of the art exposure of early embryos to oral contraceptives is not considered teratogenic. Oral contraceptive use may be continuous (estrogen and progesterone or progesterone alone) or emergency (levonorgestrel is the only drug authorized in Italy). Like all drugs oral contraceptives have a therapeutic failure rate which means that a number of women on oral contraceptives conceive each year and request genetic counseling about teratogenic effects. During the period 1998-2006 at our genetics clinic we received 89 requests for counseling regarding teratogenic risk due to oral contraceptives. Our study of these patients confirms an absence of teratogenic risk for pregnancies occurring during oral contraceptive use. Teratology counseling was useful to reassure the mothers about the low risk (in the case of oral contraceptive use alone) since only 12 women chose to terminate pregnancy.