Successful pregnancy in a living-related kidney transplant recipient who received sirolimus throughout the whole gestation.

Although more than 14,000 pregnancies have been reported worldwide in organ transplant recipients under various immunosuppressive regimens (1), pregnancy is still considered high risk for both the mother and fetus (2, 3). In fact, hypertension and some degree of renal dysfunction, which often complicate organ transplantation, are independently associated with a high risk of complication during pregnancy in otherwise healthy expectant mothers (1). Moreover, pregnancy, which is often followed by an increase in extracellular volume, may indirectly induce graft deterioration because the blood levels of the immunosuppressants become more difficult to manage, as they will distribute to a larger volume than normal (1). When weighing the risks for the fetus, there is still a great deal of ambiguity about whether sirolimus (SRL) is intrinsically teratogenic, and it is therefore contraindicated for pregnancy under normal occasions (4). However, being a relatively new drug, its real safety has not yet been determined, and despite warnings against the use of SRL during pregnancy, there are no concrete data to confirm that SRL is teratogenic. To date, nine live births in renal transplant (RT) recipients who were receiving SRL have been reported to the National Transplantation Pregnancy Registry (5). In addition, there has been only one live birth in which SRL, despite its possible intrinsic teratogenicity, was continued after confirmation of pregnancy in a RT recipient (3, 5). Further, pregnancy can be especially risky in combination with poor graft function of the mother (namely, serum creatinine levels >1.5 mg/dL). We herein report the first case of a successful pregnancy in a RT recipient in conjunction with poor graft function of the mother in which SRL was continued throughout the whole gestation.