[Effect of oral contraceptives on developmental anomalies and on the sex ratio of newborn infants].

Several studies have suggested that maternal use of oral contraceptives before and early pregnancy may be associated with various congenital malformations. It had been found according to the computer-analysis of epidemiologic data of 17,031 single pregnancies--the use of oral contraceptives taken prior to conception or during early pregnancy has not been proved to increase the frequencies of the malformation of the offspring. On the other hand it was found, that oral contraception used before and in the early pregnancy increases the chance that infants delivered subsequently will be female.