1. 
   

   What key questions should the practitioner ask to ensure safe use of medication during pregnancy?

   
   
2. 
   

   What are the limitations of the Federal Drug Administration drug classification?

   
   
3. 
   

   How should the physiologic changes in pregnancy that affect medication clearance influence prescribing of medication?

Until the middle of the last century there was a widespread belief among both clinicians and patients that the human fetus grew in a protected environment that minimized any potential effects of substances ingested by the mother. This misperception ended dramatically when the effects of thalidomide became widely known to clinicians and the general public in the late 1960s. Ever since this tragedy, there has been a tendency for both patients and clinicians to approach the use of medications in pregnancy with great anxiety because of fears of causing adverse fetal effects. Despite this, use of medications during pregnancy remains widespread throughout the world. Therefore, it seems that a dichotomy exists: a widely perceived fear regarding the ingestion of medication during pregnancy juxtaposed against the practical reality that medications are necessary and continue to be used during the course of gestation.

This chapter aims to provide a helpful evidence-based approach to guide hospitalists who may be asked to consult on or care for pregnant women through this challenging terrain. Table 221-1 lists some references that discuss the safety of particular agents in pregnancy. Table 221-2 makes some clinically-based recommendations about which medications are preferred for specific indications during pregnancy. The remainder of this chapter will provide a general approach to prescribing in pregnancy that should guide the reader in the informed use of the information contained in both the listed references and the provided summary table.