Clinical trials during pregnancy: what has been done

We describe clinical trials conducted in pregnant women. We searched PubMed database for articles related to clinical trials between 01/01/2000 and 31/12/2009 involving pregnant women by using the preferred terms "pregnancy", "human", and "clinical trials". Of 1,264 retrieved publications, 762 (60%) were excluded, leaving 502 for analysis: 53% were preventive studies in maternal or fetal conditions; 47% were therapeutic trials, mostly focused on acute obstetric diseases; 66% were assigned a pharmacological intervention. The studied drugs were 16% for labour induction and 15% for abortive procedures, followed by multivitamins and micronutrients, labour analgesia and anesthesia, antibiotics, tocolytics, and antimalarial drugs. The main objectives of the studies were focused on efficacy (54%) and efficacy and safety (26%); 81% of the studies were controlled, randomized and parallel-design trials; 19% were blinded. Clinical trials in pregnant women are mainly conducted with an efficacy objective regarding maternal-fetal prevention and in obstetric diseases to study labor induction and abortive measures. This is in line with the type of intervention and drugs involved.