Pregnancy after living kidney donation, a systematic review of the available evidence, and a review of the current guidance

Abstract

Understanding and communicating the risk of pregnancy complications post‐living kidney donation is imperative as the majority of living kidney donors (LKD) are women of childbearing age. We aimed to identify all original research articles examining complications in post‐donation pregnancies and compared the quality and consistency of related guidelines. We searched Embase, MEDLINE, PubMed, society webpages, and guideline registries for English‐language publications published up until December 18, 2020. Ninety‐three articles were screened from which 16 studies were identified, with a total of 1399 post‐donation pregnancies. The outcome of interest, post‐donation pregnancy complications, was not calculable, and only a narrative synthesis of the evidence was possible. The absolute risk of pre‐eclampsia increased from ~1%–3% pre‐donation (lower than the general population) to ~4%–10% post‐donation (comparable to the general population). The risks of adverse fetal and neonatal outcomes were no different between post‐donation and pre‐donation pregnancies. Guidelines and consensus statements were consistent in stating the need to inform LKDs of their post‐donation pregnancy risk, however, the depth and scope of this guidance were variable. While the absolute risk of pregnancy complications remains low post‐donation, a concerted effort is required to better identify and individualize risk in these women, such that consent to donation is truly informed.

Long-term Outcomes Associated With Post–kidney Donation Pregnancy Complications

“…Given these numbers, it is surprising that there is little information on pregnancies after donation. [2][3][4][5][6][7][8] More studies on postdonation pregnancies and long-term outcomes are needed (1) to confirm the associations found in this study and (2) to investigate whether kidney donation contributed to longterm risks.…”

“…8 Specifically, the risk of gestational hypertension rose from 1% to 9% predonation to 4% to 12% postdonation; the risk of preeclampsia rose from 1% to 3% predonation to 4% to 10% postdonation. 8 In the general population, hypertensive disorders of pregnancy are associated with long-term maternal risk, including hypertension, cardiovascular disease (CVD), diabetes (DM), CKD, and end-stage kidney disease. [9][10][11][12][13][14][15][16][17][18] In addition, gestational DM (gDM) has been associated with subsequent development of type 2 DM and CVD.…”

“…To date, there are a limited number of studies on the outcomes of postdonation pregnancies. [2][3][4][5][6][7][8] A recent review concluded that there was no evidence of increased fetal or neonatal risk but that the maternal risks of gestational hypertension and preeclampsia rose from "a risk level below that of the general population before kidney donation to a risk level comparable with the general population postdonation." 8 Specifically, the risk of gestational hypertension rose from 1% to 9% predonation to 4% to 12% postdonation; the risk of preeclampsia rose from 1% to 3% predonation to 4% to 10% postdonation.…”

“…[2][3][4][5][6][7][8] A recent review concluded that there was no evidence of increased fetal or neonatal risk but that the maternal risks of gestational hypertension and preeclampsia rose from "a risk level below that of the general population before kidney donation to a risk level comparable with the general population postdonation." 8 Specifically, the risk of gestational hypertension rose from 1% to 9% predonation to 4% to 12% postdonation; the risk of preeclampsia rose from 1% to 3% predonation to 4% to 10% postdonation. 8 In the general population, hypertensive disorders of pregnancy are associated with long-term maternal risk, including hypertension, cardiovascular disease (CVD), diabetes (DM), CKD, and end-stage kidney disease.…”

Pregnancy outcomes after living kidney donation from a nationwide population-based cohort study from Korea

“…However, previous studies have been conducted in a limited number of patients and most women were white 17 . Another two previous studies have compared gestational hypertension or preeclampsia that occur during pregnancy before and after donation 14 , 18 .…”