The importance of pharmacoepidemiology in pregnancy-implications for safety.

INTRODUCTION: Prescription of medications to pregnant women is usually a challenge as the drug benefit has to be considered regarding its potential adverse effects. As medication use is common in pregnant women, by chance or necessity, it gives the opportunity to evaluate the consequences of prenatal drug exposure in real life through pharmacoepidemiologic studies. Area covered: Data sources are numerous. Some of them have been created for the particular purpose of assessing medications during pregnancy. Augmented databases enable the study of delayed effects in late childhood and provide information on potential confounders. Each data source exhibits strengths and weaknesses. Several designs can be used to assess the safety of medications during pregnancy. Innovative designs have been developed in order to bypass major limits of classical methods. Expert opinion: An efficient system could follow up each pregnant woman, who had taken a medication, and consider her as a precious information for the knowledge of drug potential adverse actions against the child, who must be followed up to identify long term-effects. The diversity of data sources and approaches of pharmacoepidemiologic studies, the implementation of international networks as well as the improvement of adverse signal detection are the keystones of such an evaluation.