Physiologic changes in normal pregnancy: A systems-based approach with clinical tips for the consultant

Physiologic changes occur during pregnancy to support the growth and development of the fetus. The placental hormones lead to symptomatic and biochemical adaptations in the antepartum and postpartum periods. There are anticipated changes to virtually every maternal system with most returning to the pre-pregnancy state in the postpartum period in due course. Pregnancy is often known as nature's stress test as the lack of predictable maternal adaption may indicate an underlying previously unrecognized medical condition. This article provides a systematic overview of the key physiologic changes in a healthy pregnancy and provides the foundation for physicians caring for pregnant individuals to distinguish normal physiology from pathology.