Hypospadias, loratadine use in pregnancy: no link.

A group of women who took loratadine early in pregnancy did not appear to be at increased risk for giving birth to sons with second- or third-degree hypospadias, according to a Centers for Disease Control and Prevention analysis.

The CDC based its analysis on data from the National Birth Defects Prevention Study. Babies included in the study are identified through birth defect surveillance systems in eight states; their mothers are interviewed in detail about drug exposures and genetic risks. The study population included 563 male babies with second- or third-degree hypospadias and 1,444 male control babies, all born between October 1, 1997, and June 30, 2001.

Eleven cases and 22 controls were exposed to loratadine anytime from 1 month before pregnancy through the first 3 months of gestation. After adjustment for birth month, mother's age, maternal race/ethnicity, and state of residency at time of delivery, the odds ratio for hypospadias in the sons of women taking loratadine was 0.96 (MMWR 53110]:219-21, 2004).

Because boys with first-degree hypospadias were excluded from the study, it is not possible to assess any link between loratadine exposure and the mildest form of the birth defect.