Drug treatment in pregnancy

When considering drug therapy in pregnancy, the risk of treatment for the embryo/fetus has to be weighed against the risk to the mother and the child of carrying out no treatment. This is of particular relevance in certain conditions like diabetes, epilepsy or AIDS, where the risk of embryopathy is increased when no treatment is carried out and the available drugs are potentially teratogenic. However, carefully selected drugs and close meshed monitoring may even decrease the risk for the child. In many instances, unintentional drug exposure occurs in the period before the pregnancy has been diagnosed. This may lead to additional diagnostic measures or even abortion of an otherwise wanted child. In both situations, planned and unintentional drug exposure during pregnancy, insufficient information is available on the clinical conditions relevant here and the specific drugs involved. Identification of potential teratogenic effects of a new drug takes place during the early development phase. However, animal models may not be representative of specifically human characteristics, e.g. deficiences in enzymes. Since drug treatment is generally best avoided during pregnancy, pharmacokinetic studies in this population are rare. However, physiological changes, known to be relevant for some drugs do occur during pregnancy. In order to improve knowledge on the pharmacokinetics of drugs in pregnancy, population pharmacokinetic approaches may represent a solution. Intensive efforts to investigate the efficacy and safety of drugs during pregnancy are necessary. Since controlled clinical trials are usually not feasible due to ethical reasons, intensified collection of case reports as well as epidemiological studies are warranted to gain sufficient information for the counselling of pregnant women.