Research involving fetal drug therapy: ethical, legal, and practical considerations.

Fetal drug therapies have emerged as a promising avenue for the prevention or correction of disease during fetal or immediate postnatal life. Despite slow progress, several medications have been developed for in utero therapy of disorders which relate to fetal and neonatal pulmonary, cardiac, neurologic, and growth disorders. However, ethical and regulatory constraints require protection of the mother and fetus while causing no more than necessary additional risk. Appreciating these constraints will lead to the identification of pragmatic questions which should be answered before evaluating the efficacy and safety of a particular treatment or research proposal.