Case-control study of teratogenic potential of thiethylperazine, an anti-emetic drug.

OBJECTIVE: Thiethylperazine is a commonly used anti-emetic drug during pregnancy in Hungary. One experimental study in mice and rats found an increased occurrence of cleft palate after the use of thiethylperazine during pregnancy but the human data of thiethylperazine have not been reported. Thus, the aim of the study was to investigate the possible human teratogenic effect of thiethylperazine. DESIGN: Case-control approach. SETTING: The teratogenic potential of thiethylperazine was evaluated in the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities between 1980 and 1996. SAMPLE: Of 38,151 newborn infants without any congenital abnormalities (control group), 746 (2.0%) had mothers who were treated with thiethylperazine, while of 22,843 cases with congenital abnormalities, 411 (1.8%) had mothers who were treated with thiethylperazine during pregnancy. METHODS: Case-control pair analysis. MAIN OUTCOME MEASURES: Different congenital abnormalities. RESULTS: The pairs of cases with congenital abnormalities and their matched controls without congenital abnormalities were compared and this approach showed a somewhat higher rate of cleft lip +/- palate (OR: 2.0 with 95% CI: 1.0-4.0) in infants born to mothers with thiethylperazine treatment during the first trimester of pregnancy. CONCLUSION: Our data do not indicate clear teratogenic effect of thiethylperazine, however, a weak association was found between thiethylperazine use and cleft lip +/- palate.