Uterus transplantation (UTx) is an effective treatment option for uterine factor infertility. However, the need for immunosuppression and congenital renal anomalies that coexist with uterine agenesis in about 30% of women with Mayer-Rokitansky-Kuster-Hauser syndrome create a risk for renal dysfunction.
We therefore examined renal function trajectory and related pregnancy complications in an international cohort of 18 UTx recipients from September 2016-February 2020 who had at least one live birth. All UTx recipients had a diminution in their renal function that was apparent starting at 30 days posttransplant and in half the reduction in eGFR was at least 20%; the decrease in eGFR persisted into the early post-partum period.
Half met criteria for Stage 1 acute kidney injury (AKI) as defined by the AKI Network criteria during their pregnancy. Overall, 28% of UTx recipients developed pre-eclampsia. eGFR was lower at embryo transfer and throughout pregnancy among those who developed pre-eclampsia, reaching statistical significance at week 16 of pregnancy.
This effect was independent of tacrolimus levels. Mean eGFR remained significantly lower in the first 1-3 months after delivery.
In the subgroup who reached 12 months of postpartum follow up and had a graft hysterectomy (n = 4), there was no longer a statistical difference in eGFR (pretransplant 106.7 ml/m +- 17.7 vs. 12 mos postpartum 92.6 ml/m +- 21.7, p = .13) but the number was small. Further study is required to delineate long term renal risks for UTx recipients, improve patient selection, and make decisions regarding a second pregnancy.