Pregnancies in Living Kidney Donors

Area of Science:

• Nephrology
• Obstetrics
• Public Health

Background:

• Kidney donation is predominantly performed by women, yet data on pregnancy outcomes post-donation are limited.
• Understanding risks is crucial for informed counseling of living kidney donors.
• Previous studies have not fully elucidated the association between kidney donation and adverse pregnancy outcomes.

Purpose of the Study:

• To assess the association between living kidney donation and adverse maternal and fetal pregnancy outcomes.
• To investigate if kidney donation increases the risk of complications like pre-eclampsia and small-for-gestational-age infants.
• To provide evidence-based information for pre-donation counseling.

Main Methods:

• Nationwide registry-based cohort study in Sweden (1973-2022).
• Inclusion of women ≤45 years with births before and/or after kidney donation.
• Dual study design: post-donation pregnancies compared to matched controls and pre-donation pregnancies as within-donor controls.

Main Results:

• Post-donation pregnancies showed significantly higher rates of low-birth-weight infants (9.4% vs. 3.7%) and small-for-gestational-age (SGA) infants (5.8% vs. 2.2%).
• The combined outcome of pre-eclampsia and SGA was more frequent post-donation (OR 2.08).
• A trend towards increased preterm birth was observed post-donation (9.4% vs. 5.0%).

Conclusions:

• No clear excess risk of pre-eclampsia was identified in pregnancies following kidney donation.
• Modestly increased risks of low-birth-weight and SGA infants were observed, though absolute risks were low.
• Findings support individualized counseling and enhanced monitoring for pregnancies in kidney donors.