Introduction: Pregnancy post-kidney transplantation carries higher risks of preterm birth, preeclampsia, and adverse fetal outcomes (1, 2). Concerns about the impact of pregnancy on graft function influence parenthood decisions and this knowledge gap is crucial to address in preconception counselling(3).
Objective: To evaluate the impact of pregnancy on graft survival in women with a functioning kidney transplant compared to matched non-pregnant controls.
Methods: Observational study of Australian and New Zealand Dialysis and Transplant (ANZDATA) Registry data. Graft survival was compared between women aged 15-49 years with a functioning kidney transplant with a first pregnancy between 2001-2023, and matched non-pregnant women. Matching was based on transplant duration, preconception serum creatinine, and maternal age. Surgical terminations were excluded. Multiple pregnancies and pregnancies ending with miscarriages at >20 weeks gestation were included. Graft survival was calculated from the time of conception.
Results: 286 first pregnancies in 284 women with a kidney transplant were compared to 286 matched women. Mean maternal age at conception was 32±4.9 years with median preconception serum creatinine 103µmol/L (interquartile range [IQR]:88-123). Median transplant duration at conception was 4.5 years (IQR:2.5-8). After median follow-up of 8.7 years from conception, pregnancy was not associated with poorer graft survival after adjusting for maternal age, preconception creatinine, donor source, graft number and time from start of dialysis until transplantation (HR 1.21 (95%CI:0.89, 1.64).
Conclusion: Pregnancy in women with a functioning kidney transplant was not associated with adverse impact on long-term graft survival. These findings will inform clinicians and women considering pregnancy after transplantation.