Principles of Pharmacokinetics During Pregnancy in Women and Their Fetuses-An Update.

Pregnancy profoundly impacts normal physiology. When combined with the growth of the developing fetus and placenta, these changes result in multiple alterations in drug absorption, distribution, metabolism, and elimination. In this context, physiology-based pharmacokinetics modeling provides a powerful tool that can anticipate altered pharmacokinetics in pregnant women and predict maternal and fetal drug exposure in clinical scenarios that are untested or untestable, thereby contributing to an evidence-based approach to pharmacotherapy in pregnant patients. Although concerns about fetal safety have historically limited pharmacokinetic studies, many medications are clinically indicated for various maternal or fetal conditions and need further study.