Drug utilization during pregnancy is an increasing trend; meanwhile, medical practice incorporates risk as a concept. The thalidomide tragedy was a landmark example of the risks associated with drug use during pregnancy. Nevertheless, prescriber perceptions regarding pregnancy and drug use still oscillate between certainty of harm and belief that drugs are relatively safe (unless the contrary is proven). There is need for scientific evidence to support clinical decisions. The randomized clinical trial is regarded as the basis for the evidence-based medicine paradigm. This paper discusses the circumstances in which different types of clinical studies are appropriate in pregnancy. Expanded use of pharmacoepidemiology, mainly through analytical studies (such as cohort studies), can be a key complementary alternative to the construction of clinical evidence in this population. These studies, if submitted to rigorous methodological guidelines, may offer sound, hypothesis-generating information essential to clinical practice.
Pregnancy; Drug use; Clinical trial; Evidence-based medicine; Pharmacoepidemiology
