Effects of drugs on the fetus.

Most drugs are not labelled for use in pregnancy. Consequently, large numbers of women expose their fetus to potential risks, either because they do not know that they are pregnant or because they require treatment for gestational pathologies. The present review focuses on drug classes for which the risk:benefit ratio during pregnancy has been discussed recently based on human data. Selective serotonin reuptake inhibitors have gained wide acceptance in the treatment of depression and data on their risk for neonatal adaptation after late exposure are reviewed. Angiotensin converting enzyme inhibitors and angiotensin II receptors antagonists interact with the renin-angiotensin system, although with different mechanisms, and might cause severe fetal tubular dysgenesis. Non-steroidal anti-inflammatory and antiviral drugs and recreational drugs are also presented.