Background: Animal and limited human studies have raised concerns as to the safety of in utero exposure to mycophenolate mofetil (MMF) and sirolimus (SRL) in transplant recipients. This study examined the outcomes of pregnancies with exposure to MMF or SRL from 30 female transplant recipients (39 pregnancies) who have reported pregnancies to the National Transplantation Pregnancy Registry.
Methods: Data were collected via questionnaires, phone interviews and medical records.
Results: There were 18 kidney recipients reporting 26 pregnancies with exposure to MMF: 15 livebirths (LB), 11 spontaneous abortions (SA). Structural malformations were reported in four of the 15 children (26.7%) including: hypoplastic nails and shortened fifth fingers (one), microtia with cleft lip and palate (one), microtia alone (one), and neonatal death with multiple malformations (one). One kidney/pancreas (K/P) recipient reported one SA. Three liver recipients reported three pregnancies; two LB (no malformations), and one second trimester SA. Two heart recipients reported one LB (no malformations) and two SA. SRL exposures included seven recipients (four kidney, one K/P and two liver) reporting four LB (one infant whose mother was switched from MMF to SRL during late pregnancy had cleft lip and palate and microtia) and three SA.
Conclusions: A higher incidence of structural malformations was seen with MMF exposures during pregnancy compared to the overall kidney transplant recipient offspring, while no structural defects have as yet been reported with early pregnancy sirolimus exposures. Centers are encouraged to report all pregnancy exposures in transplant recipients.