Immunosuppression in pregnancy: choices for infant and maternal health.

Successful pregnancy outcomes are possible after all types of solid organ transplantation and thousands of successful pregnancies in such women have been reported. As immunosuppressive medications are required to maintain adequate graft and maternal survival, major concerns are the effect of these agents on the fetus and the effect of pregnancy on the well being of mother and graft, against a background of continuing advances and modifications in immunosuppressive therapy. Women should avoid unnecessary medications during pregnancy but clinicians worry most about teratogens; agents (environmental, pharmaceuticals or other chemicals) that cause abnormal development, whether this be an overt structural birth defect or more subtle derangements of embryonic or fetal development. A concern is that any agent or combination of agents and maternal condition(s) may be teratogenic, a risk that is increased in the transplant population. The goal of immunosuppression is to ensure graft and patient survival by preventing acute rejection. Combinations of agents allow for synergistic effects while minimising drug toxicities. No specific combination has been deemed optimal and the effects of more recently available combinations require further study. Although there are known theoretical risks to mother and fetus, successful pregnancies are now the rule in transplant recipients. This is without an apparent increase in the type or incidence of malformations in the newborns, and usually with no evidence of graft dysfunction and/or irreversible deterioration either related to prepregnancy graft problems or unpredictable gestational factors. For immunosuppression, what is best for the mother and her survival should ensure the best outcome for the fetus and, although no specific malformation pattern has been reported to date, there are some interesting trends worthy of continued analyses. A balance of good maternal and graft outcome with the lowest risk of fetal toxicity must be the goal of management.