Immunosuppressant therapy during gestation.

Use of immunosuppressants during pregnancy is indicated for anti-rejection therapy in transplantation patients and treatment of autoimmune diseases. Maternal side effects include nephrotoxocity and hepatotoxicity. All immunosuppressant drugs cross the placenta. Immunosuppressant use during the first trimester is not strongly associated with an increased risk of congenital anomalies, although some agents (eg, azathioprine) may be associated with slightly increased frequencies of birth defects. Effects of exposure to this class of drugs during the second and third trimesters affects the fetus' immune system. The result is an infant with a transiently compromised immune system at an increased risk of slightly lower birth weight. Other direct toxic effects of the drugs on the infant's pancreas, liver, and lymphocytes are reported. Certain agents (eg, penicillamine, chloroquine) should be avoided during pregnancy, if possible. However, their use cannot be discontinued during pregnancy given the life-threatening nature of the indication for use of immunosuppressants.