The Experience of Pregnancy After Renal Transplantation: Pregnancies Even Within Postoperative 1 Year May Be Tolerable

BACKGROUND: To identify factors related with successful pregnancy in renal transplant recipients and the effect of pregnancy on long-term graft outcome. METHODS: The study group consisted of 48 women who conceived after undergoing renal transplantation (total pregnancies 74). The control group consisted of 187 nonpregnant female renal transplant recipients. RESULTS: Mean ages at the time of transplantation and pregnancy were 28.0+/-4.0 years and 31.6+/-4.1 years, respectively. The mean interval from transplantation to pregnancy was 40.2+/-27.1 months. Outcomes included 49 live births, 12 terminations, 9 miscarriages, 3 stillbirths, and 1 ectopic pregnancy. Eleven of the 74 pregnancies (15%) were within 1 year of transplantation, resulting in seven live births, two miscarriages, and two terminations. Live births were associated with younger age at the time of transplantation (relative risk, 0.75; P=0.042) and younger age at the time of pregnancy (relative risk, 0.76; P=0.022). Graft failure rate from transplantation to end of follow-up did not differ between the pregnant and nonpregnant groups (19% vs. 21%, P=0.688). The 10-year graft survival rates were also similar in the 11 women who became pregnant less than or equal to 12 months after transplantation and the 37 who became pregnant more than 12 months after transplantation (78.8% vs. 78.6%, P=0.941). CONCLUSION: A younger age at transplantation and at pregnancy was associated with a greater likelihood of a live birth. Transplantation to conception interval of less than 1 year was not associated with a greater number of adverse pregnancy events when compared with the group with transplantation to conception interval greater than 1 year.