Maternal and neonatal outcomes in kidney transplant recipients: a single-center observational study.

Objective: Pregnancy poses a high risk for adverse maternal and neonatal outcomes in kidney transplant recipients (KTRs), and data on long-term allograft functions compared to the healthy population are still limited. Therefore, we aimed to conduct a comparative analysis of maternal and neonatal outcomes in KTRs.

Subject and methods: In this retrospective single-center study, KTRs who experienced pregnancy after transplantation were evaluated in comparison with an age-matched non-transplanted control group. Maternal outcomes included obstetric complications (preeclampsia, peripartum hemorrhage, duration of maternal hospitalization) and a composite kidney outcome for KTRs defined as progression to graft failure necessitating dialysis or retransplantation or doubling of serum creatinine at the end of follow-up. Neonatal outcomes were gestational age, preterm birth, newborn mortality, admittance to the neonatal intensive care unit (NICU), Apgar scores, and birth weight.

Results: In 53 KTRs, 68 pregnancies occurred. Preeclampsia (p < 0.001) and preterm birth (p = 0.003) were significantly higher in KTRs. The KTR pregnancies had lower mean birth weights (p = 0.001) and longer durations of maternal hospitalization (p = 0.001). Neonatal mortality, NICU admissions, peripartum hemorrhage rates, and Apgar scores were similar between groups. Follow-up for a median of 105 months after the index birth showed higher serum creatinine levels at postpartum visits (p < 0.001) and at the last follow-up (p = 0.001) compared to baseline. Of the KTRs 6 (11.3%) experienced composite kidney outcomes, including 5 patients with graft failure and 1 with a doubling of serum creatinine.

Conclusion: The KTRs exhibit comparable neonatal mortality and NICU admission rates but have higher rates of preeclampsia and preterm birth. Importantly, graft functions worsen significantly during postpartum follow-up.