[Drug safety in pregnancy-a particular challenge].

Drug safety in pregnancy is of utmost importance because prenatal exposure to the unborn child may result in side effects with life-long consequences. Data on their risks in pregnancy are scarce for many drugs. Furthermore, there is often uncertainty how to translate risk data into practice.This article aims to identify tools to improve data ascertainment on exposed pregnancies and their outcome. Using the example of the German Embryotox institute, it is demonstrated how to disseminate drug safety knowledge to healthcare professionals and patients for clinical decision-making.Observational data are the most important basis for drug risk assessment in pregnancy. Such data are collected by Embryotox through the risk consultation process. Prospective cohort studies with comparison cohorts allow to estimate relative risks for birth defects, pregnancy loss, and other developmental anomalies. Retrospectively ascertained adverse drug reactions contribute to identification of distinct pattern of congenital anomalies.Drugs in pregnancy counselling require risk characterization dependent on the individual clinical setting: recommendation of treatment of choice (comparative risk assessment between effective drugs), individual risk estimation after (inadvertent) exposure, and assessment of causal relationship in cases of congenital anomalies. Combining counselling and protocols of pregnancy outcome after drug exposure is optimal to cost-efficiently ascertain data of high quality.Using acetaminophen, valproic acid, AT1-receptor blockers and retinoids as examples, recent discussions on drug risks in pregnancy and their clinical implications are presented.