As a rule, all diseases which subject the organism to a considerable strain are much more serious when occurring in a pregnant woman.
—J. Whitridge Williams (1903)
As reviewed by Williams in 1903, pregnant women are susceptible to any medical and surgical disorder that can affect childbearing-aged women. Some of these, especially those that are chronic, more often precede pregnancy. But, they can acutely complicate an otherwise normal pregnancy. Of estimates, one managed-care population had an overall antenatal hospitalization rate of 10.1 per 100 deliveries (Gazmararian, 2002). Approximately one third was for nonobstetrical conditions that included renal, pulmonary, and infectious diseases. In another study from the 2002 Nationwide Inpatient Sample, the injury hospitalization rate was 4.1 women per 1000 deliveries (Kuo, 2007). Last, approximately 1 in every 635 pregnant women will undergo a nonobstetrical surgical procedure (Corneille, 2010; Kizer, 2011).
Obstetricians should have a working knowledge of the wide-ranging medical disorders common to childbearing-aged women. Many of these are within the purview of the general obstetrician. Other disorders, however, will warrant consultation, and still others require a multidisciplinary team. The latter may include maternal-fetal medicine specialists, hospitalists, internists and medical subspecialists, surgeons, anesthesiologists, and numerous other disciplines (Levine, 2016). The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine (2014, 2015) has redefined aspects of maternal care and proposed required levels of specialized care.
It should be axiomatic that a woman must never be penalized because she is pregnant. To ensure this, several questions should be addressed:
What management would be recommended if the woman were not pregnant?
If the proposed management is different because the woman is pregnant, can this be justified?
What are the risks versus benefits to the mother and her fetus, and are they counter to each other?
Can an individualized management plan be devised that balances benefits versus risks of any alterations?
Such an approach allows individualized care for women with most medical and surgical disorders complicating pregnancy.
MATERNAL PHYSIOLOGY AND LABORATORY VALUES
Pregnancy induces physiological changes in virtually all organ systems. In turn, results of numerous laboratory tests are altered, and some values would, in the nonpregnant woman, be considered abnormal. Conversely, some may appear to be within a normal range but are decidedly abnormal for the gravida. These changes may amplify or obfuscate evaluation of coexisting conditions. The wide range of pregnancy effects on normal physiology and laboratory values are discussed in the chapters that follow in this section and are listed in the Appendix.
MEDICATIONS AND SURGERIES
Fortunately, most medications needed to treat frequently encountered illnesses complicating pregnancy can be given with relative safety. That said, notable exceptions are considered in Chapter 12 and throughout this text.