41 - Care of the peripartum patient

Summary

Introduction

The past two decades have brought a greater understanding of pregnancy along with advances in the recognition and management of disorders that are unique to pregnancy or complicate pregnancy. Increasingly, generalist physicians are being asked to assist in the management of medical conditions that develop prior to or as a result of pregnancy. Coverage of the breadth of medical disorders that can complicate pregnancy is the topic of several excellent textbooks. Instead, this chapter focuses on the medical care of several conditions that are unique to pregnancy or influenced by the physiologic changes that occur around late pregnancy, labor, delivery and the immediate postpartum period.

Normal physiologic changes in pregnancy

Knowledge of the normal physiologic changes that occur with pregnancy is important to understand the effect that existing maternal disease has on maternal and fetal health. A few of the more important physiologic changes associated with pregnancy are listed in Table 41.1.

The hemodynamic adaptations are some of the most significant physiologic changes that occur during pregnancy. Soon after implantation systemic vascular resistance (SVT) falls. This adaptation, mediated by gestational hormones, prostaglandins and the creation of a low resistance circulation in the uterus and placenta, reaches its nadir at 20 weeks gestation. During the latter half of pregnancy, the SVR rises, reaching near normal levels at term. Cardiac output rises 30%–50% during pregnancy. An increased stroke volume, a result of expanded blood volume, accounts for the majority of the increase in CO in the early stages of pregnancy.