Report from the National Transplantation Pregnancy Registry: outcomes of pregnancy after transplantation.

Experience in the field of pregnancy posttransplantation has been gained through continued case reports, center reports, and registry data. The NTPR maintains an ongoing active database to study the safety of pregnancy and includes the outcomes of female transplant recipients as well as male recipients who father pregnancies. Analyses are ongoing and include long-term followup of recipients' graft status and of their offspring. For the most part, guidelines proposed in 1976 for counseling recipients remain applicable (30). While these counseling guidelines were formulated for kidney recipients, they may be extrapolated to other organ recipients as well. Organ-specific issues should also be considered in managing and counseling female transplant recipients. Recipients should be in general good health, and graft function should be stable and, ideally, rejection-free. There should be optimal control of comorbid conditions such as hypertension and diabetes prior to conception. While the shortest safe interval from transplant to conception has not been established, 1 year is a reasonable milestone, given the prerequisites of stable, adequate graft function and maintenance-level immunosuppression. During pregnancy, maintenance-medication regimens should be continued with vigilant monitoring for effective drug levels and drug side effects with appropriate dose adjustment. These pregnancies are high-risk and require close maternal and fetal surveillance through coordinated care among maternal-fetal medicine specialists and transplant personnel. Of the live born reported to the NTPR, a higher incidence of structural malformations has been seen with MMF exposures during pregnancy when compared with the overall kidney transplant recipient offspring group. Three of the four defects included microtia (ear deformity), suggesting a pattern of malformations. However, live-born outcomes without structural malformations have also been noted in the MMF cohort. No structural defects have yet been reported with early pregnancy sirolimus exposures in a limited number of recipients evaluated. Limitations in assessing congenital malformation risk and MMF exposure include methodology and potential reporting bias, small sample size, and our inability to exclude other comorbid factors such as non-immunosuppressive drug effects or other susceptibilities in this population. It is incumbent upon transplant professionals to be aware of any additional risk to the fetus from immunosuppressive medications relative to the potential improvement in maternal graft function/survival conferred by each of these agents. Given the ongoing concerns with the newer immunosuppressive agents, clinicians are responsible for providing pregnancy counseling in all pre- and post-transplant recipients of childbearing age. Centers are encouraged to report all pregnancy exposures in transplant recipients to the NTPR. Future analyses from the NTPR are directed at potential effects of these newer immunosuppressive regimens, not only from immediate exposure but also from continued exposure that may occur from breastfeeding. As the registry study design allows for contact between registry staff and recipients and their health care providers, efforts are ongoing to analyze the long-term outcomes of parents and children. Continued close collaboration among specialists will help to better identify potential pregnancy risks in these populations, particularly as new immunosuppressive agents are developed. The fiftieth anniversary of the first post-transplant pregnancy (reported by Joseph Murray et al.) (31) will be in March 2008. With this important date approaching and with ongoing pregnancy issues concerning post-transplant pregnancy safety, this is an ideal time to raise awareness of the need for continued worldwide cooperation for data collection. Enhanced assessment of pregnancy safety is essential to the development of guidelines for counseling and management of pregnancy in the transplant population.