Abstract
The Swedish Medical Birth Registry was used for the monitoring of maternal drug usage in early pregnancy and the occurrence of congenital malformations in infants. An association between maternal use of the anti‐allergic drug loratadine and infant hypospadias was noticed. Continued monitoring suggested that this was probably not a chance phenomenon, but a biological mechanism which could explain the association is unknown. Comparisons with the outcome after exposure for other anti‐allergic drugs suggested a drug specificity.