Never penalize a woman because she is pregnant. Pregnant women are susceptible to any of the medical and surgical disorders that can affect childbearing-aged women. Some of these, especially those that are chronic, more often precede pregnancy. But, they as well as others can acutely complicate an otherwise normal pregnancy. It is difficult to accurately quantify nonobstetrical disorders that complicate pregnancy, however, some estimates can be made. For example, one managed-care population had an overall antenatal hospitalization rate of 10.1 per 100 deliveries (Gazmararian, 2002). Of these, approximately a third were for nonobstetrical conditions that included renal, pulmonary, and infectious diseases. In another study from the 2002 Nationwide Inpatient Sample, the injury hospitalization rate was found to be 4.1 women per 1000 deliveries (Kuo, 2007). Approximately 1 in every 635 pregnant women will undergo a nonobstetrical surgical procedure (Corneille, 2010; Kizer, 2011).
Many of these nonobstetrical disorders are within the purview of the obstetrician. Some, however, will warrant consultation, and still others require a multidisciplinary team. The latter may include maternal-fetal medicine specialists, internists and medical subspecialists, surgeons, anesthesiologists, and numerous other disciplines (American College of Obstetricians and Gynecologists, 2013). In these latter situations, obstetricians should have a working knowledge of the wide range of medical disorders common to childbearing-aged women. At the same time, nonobstetricians who help care for these women and their unborn fetuses should be familiar with pregnancy-induced physiological changes and special fetal considerations. Many of these normal pregnancy perturbations have clinically significant effects on various diseases and cause seemingly aberrant changes in routine laboratory values.
It should be axiomatic that a woman should never be penalized because she is pregnant. To ensure this, a number of questions should be addressed:
What management plan would be recommended if the woman was 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 the benefits versus risks of any alterations?
Such an approach should allow individualization of care for women with most medical and surgical disorders complicating pregnancy. Moreover, it may be especially helpful for consideration by nonobstetrical consultants.
Maternal Physiology and Laboratory Values
Pregnancy induces physiological changes in virtually all organ systems. Some are profound and may amplify or obfuscate evaluation of coexisting conditions. Coincidentally, 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 pregnant woman. The wide range of pregnancy effects on normal physiology and laboratory values are discussed in the chapters that follow as well as throughout Chapter 4 and the Appendix.