Introduction

The hormonal environment during pregnancy leads to significant changes in the integumentary system of virtually all pregnant women. In a few, skin changes may become pathologic. Likewise, women with nonpregnancy-related skin disorders may become pregnant, and the pregnancy may affect the course of the disease or, alternatively, the skin disorder may adversely affect the mother or the fetus. This chapter will focus on (1) normal changes of the skin during pregnancy, (2) pathologic skin disorders that occur primarily in pregnant women, (3) other dermatologic disorders with significant effects on the mother and/or fetus, and (4) the anesthetic considerations for women with these dermatologic disorders. Certain diseases that affect the skin in pregnancy, such as autoimmune diseases, are discussed in detail in other chapters. These diseases may be mentioned only in passing in the current chapter, even though the degree of skin involvement may be substantial.

Functions of the skin

The integumentary system comprises approximately 16% of body weight. It is a system containing multiple tissues including skin itself (epidermis, dermis, and hypodermis), glands (sudoriferous and sebaceous), hair, nails, nervous tissue, blood vessels, and even muscle (piloerector muscles). Although considered a single organ, the skin serves multiple discrete and interactive functions. As a barrier, it protects the body from physical agents, mechanical injury, dehydration, and ultraviolet radiation. The proper balance of collagen and elastic fibers gives skin flexibility while preventing overstretching. The skin's secretory glands, fat, and vascular system help regulate body temperature.

It has been almost ten years since the first edition of Obstetric Anesthesia and Uncommon Disorders was published. Over the past few years colleagues have asked the editors when they could expect to see a new edition. We had some hesitation, not least of which was because we felt that many practioners could find most of this information for themselves using the internet or subspecialty journals. Upon reflection, we recognized that there is no substitute for a textbook that contains information gathered and carefully reviewed by a number of devoted specialists. Hence, spurred on by those requests for a second edition it was decided to create a revision that provides more recent references and reflects some of the changes in obstetric anesthesia practice that have occurred over the past ten years. With the assistance of a third editor, Robert S. F. McKay, we recruited some outstanding new contributors from around the world and created a second edition that we trust the reader will find useful. We have continued to use chapters based on body systems and diseases. We have consolidated some chapters, split others, and added two new chapters, namely ‘Chronic pain in pregnancy’ and ‘Malignancy and pregnancy’. There are now 23 chapters each illustrated with figures, tables, and photographs, and each chapter is accompanied by a comprehensive list of updated references.

Bacterial infections

Clinical features: fever and asymptomatic patient

Fever during pregnancy can result from a variety of infections, tissue trauma, malignancy, epidural analgesia, drug administration, and endocrine or immunologic disorders. Infection is the most common cause, reflecting the effect of pyrogens on the hypothalamus. Bacterial infections of the skin, periodontal tissues, respiratory and genitourinary tracts can lead to pregnancy-related complications such as preterm labor, premature rupture of membranes, abortion following pelvic inflammatory disease, chorioamnionitis, neonatal infections, cervicitis, urethritis, ectopic pregnancy, low birthweight, stillbirth, pneumonia, septicemia, and both maternal and neonatal death. Urinary tract bacterial infections usually arise from preexisting covert bacteriuria and experts recommend screening and eradication of these silent infections as routine prenatal practice. Antibiotic treatment during pregnancy is beneficial in reducing neonatal and maternal morbidity/mortality, and most bacterial infections are preventable and treatable. Clindamycin in early pregnancy can reduce the risk of preterm birth by 40–60%. Vaginal bacterial diseases are often asymptomatic and have little impact on management by the obstetric anesthesiologist. The more common bacterial infections and related complications are listed in Table 18.1.

Maternal and fetal implications

The incidence of maternal infection during labor has been estimated to be about 3%. Severe sepsis is less common, however, and presents as the primary problem in < 1% of patients. However, sepsis remains a significant cause of maternal death in underdeveloped countries. In pregnancy, there are decreases in immunoglobulin G levels, lymphocyte count, and impaired lymphocyte activity.