Pregnancy following kidney transplantation - impact on mother and graft function and focus on childrens’ longitudinal development

BACKGROUND: Pregnancy after kidney transplantation has been considered as high risk for maternal and fetal complications. After careful patient selection successful pregnancies are described. Little is known about fetal outcomes and data is particularly scarce on childrens´ early development up to two years when born to kidney/−pancreas transplant recipients. Here, we analyzed maternal and fetal risk and evaluated graft function during pregnancy in transplanted women. We aimed to identify factors affecting the outcomes of mothers and their grafts during pregnancy and of children up to 2 years after delivery/ birth. METHODS: All consecutive pregnancies in kidney/ kidney-pancreas recipients with live-born children from 2002 to 2016 were evaluated in two transplant centers (Charité Berlin/ University Tuebingen). All data was gathered from medical records. Impact of pregnancy on obstetrical risks, graft function and fetal development was evaluated. Additionally, for the first time development of children, including physical examination and assessment of neurological function were evaluated at 12 and 24 months. RESULTS: Thirty-two pregnancies in 28 patients with a median duration of 34 gestational weeks (range, 24–38) were analyzed. 13 patients (46.4%) developed deterioration of kidney graft function > 10 ml/min during pregnancy. In majority, caesarean section was performed (75%). Twenty-five (78.1%) children were born prematurely, thereof (16%) < 28 weeks. Almost 70% had low birth weights (LBW) (< 2.500 g); median birth weight was 2.030 g. General health and physical constitution of children were unremarkable with normal development in 94% at 12 and 24 months of corrected age, respectively. CONCLUSION: Despite the high rate of preterm birth and LBW, development up to two years was age-appropriate in this cohort. Due to low absolute numbers, increasing efforts in centralized counseling, diagnostics and committed specialist support are required. Decisive treatment of these high-risk patients in specialized units leading to better performance of these patients (mother/ fetus) is deemed superior. In order to confirm this, prospective studies on neonatal and pediatric outcomes with a standard-of-care comparator arm will be conducted.