Pregnancy in kidney transplant recipients tied to Postpartum Creatinine Elevation Without Long-Term Graft Impact: Study

The study, published in International Urology and Nephrology, systematically reviewed and analyzed existing evidence on the long-term effects of pregnancy in women who have received kidney transplants. Mehmet Kanbay, Department of Medicine, Division of Nephrology, Koc University School of Medicine, Istanbul, Turkey, and colleagues aimed to clarify uncertainties surrounding how pregnancy may influence graft function, patient survival, and other key clinical parameters such as serum creatinine, estimated glomerular filtration rate (eGFR), and proteinuria.

Pregnancy after kidney transplantation involves significant physiological shifts that may place stress on the transplanted kidney. While some earlier research had indicated minimal long-term effects, the inconsistency of findings warranted a detailed investigation. The comprehensive review and meta-analysis pooled data from 19 eligible studies out of more than 6,000 screened publications. All included studies compared outcomes in pregnant kidney transplant recipients with non-pregnant transplant recipients, focusing on adults over the age of 18.

The study revealed the following findings:

• The likelihood of graft failure was similar in both pregnant and non-pregnant kidney transplant recipients, with no statistically significant difference (OR 1.13).
• Although the rate of adverse graft outcomes was slightly higher among pregnant patients (25.4%) compared to non-pregnant patients (19.8%), this did not result in a significant difference in overall graft survival.
• Mortality rates showed no significant difference between the two groups, with an odds ratio for all-cause mortality of 0.63, indicating no increased risk of death linked to pregnancy post-transplant.
• The meta-analysis reported low heterogeneity across studies, supporting the consistency and reliability of the results.
• There was a significant increase in serum creatinine levels after delivery in pregnant transplant recipients compared to their pre-pregnancy levels (Standardized Mean Difference −0.33).
• Despite fluctuations in kidney function during and after pregnancy, the findings suggest that the long-term impact on graft health is minimal.

The study emphasizes the importance of trimester-specific monitoring and follow-up for pregnant kidney transplant recipients. Given the slight increase in adverse outcomes and changes in kidney function markers, the authors recommend close monitoring protocols during and after pregnancy. Establishing clear thresholds for intervention based on trimester-specific variations may help prevent complications and preserve graft function in the long run.

"Pregnancy appears to be safe in women with a kidney transplant when managed appropriately. While there is a measurable increase in creatinine levels postpartum, the overall risks of graft loss or mortality remain comparable to those who do not conceive after transplantation," the authors wrote, adding that the findings offer reassurance to both clinicians and patients, while also underscoring the importance of vigilant follow-up care during pregnancy.

Reference:

Kanbay, M., Brinza, C., Ozbek, L. et al. Long-term impact of pregnancy on mortality and graft outcomes in kidney transplant recipients: a systematic review and meta-analysis. Int Urol Nephrol (2025). https://doi.org/10.1007/s11255-025-04572-5