IMMUNOSUPPRESSIVE DRUGS AND PREGNANCY

Immunosuppressive therapy is commonplace in the modern practice of med icine. For some conditions, such as organ transplantations, new and mo re aggressive treatments have improved the feasibility of pregnancy in women who are invariably taking immunosuppressive agents. For other c onditions, such as moderate-to-severe asthma or systemic lupus erythem atosus, better immunosuppressive regimens and a shift in medical opini on regarding the advisability of pregnancy have led to increased numbe rs of affected women who choose to become pregnant. One of the most dr amatic advances in modern medicine, a combination of high-dose chemoth erapy with allogenic or autologous bone marrow transplantation, has gr eatly improved the survival of women with certain neoplastic diseases such that pregnancy is a realistic option. In these times, obstetricia ns face the task of caring for women who have used or are currently us ing one or more potent immunosuppressive medications. The purpose of t his article is to assess and summarize our current knowledge regarding the use of immunosuppressives in pregnancy, focusing primarily on the ir effects on the mother and fetus. The reader should understand, howe ver, that most of our current knowledge in this area is derived from l imited animal studies, case reports, and small case series. It is like ly that pregnancy-induced immunologic changes alter both the response and the potential adverse effects of many immunosuppressive agents. Fo r example, pregnant women have lower peripheral CD4 lymphocyte counts, depressed interleukin-2 production and natural killer cell function, and increased circulating levels of complement proteins compared to no npregnant women.(10) Both the dose and timing of drug exposure may be important, and effects of immunosuppressive agents on immunologic inte ractions at the critical maternal-fetal interface may be pivotal.