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

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.

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.

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.

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.