MO149PREGNANCY AFTER LIVING KIDNEY DONATION, A SYSTEMATIC REVIEW OF THE AVAILABLE EVIDENCE AND A REVIEW OF THE CURRENT GUIDANCE
Authors: Pippias Maria , Skinner Laura , Varberg Reisæter Anna , Abramowicz Daniel , Noordzij Marlies , Stel Vianda , Jager Kitty J 
Published: May 2021

Abstract

Background and Aims
It was long believed that living kidney donation did not infer a risk to the health or longevity of living kidney donors (LKD), though recently, some studies have called this into question. The majority of LKD are women of childbearing age, it is therefore vital that a clear picture of the risks associated with pregnancy post-kidney donation is obtained. Furthermore, it is imperative that the guidance pertaining to accepting an LKD of childbearing age is both comprehensive and clear.
We performed a systematic review with the aim of identifying all original research articles examining pregnancy outcomes, such as gestational hypertension and pre-eclampsia in LKD, and to compare the quality and consistency of the guidelines, consensus statements and expert opinions in this area.

Method
We searched Embase Ovid, MEDLINE Ovid, PubMed, society webpages and guideline registries for English-language publications published up until 18th December 2020. Article references and citation lists were also examined. The study was performed in accordance with the PRISMA guidelines.

Results
A total of 94 articles were screened. Nine cohort studies, two case reports, and one congress abstract were identified. The four most recent published papers were retrospective cohort studies, which included a combined number of 1,298 LKDs. All four studies reported an increase in both the relative and absolute risk of pregnancy-related complications. For example, the absolute risk of pre-eclampsia increased from ∼1-3% of pregnancies in LKD pre-donation to ∼4-6% of pregnancies in LKD post-donation. This meant that LKDs had a lower absolute risk of pre-eclampsia pre-donation, but after donation their risk of pre-eclampsia matched that of the general population. None of these studies distinguished between early or late onset pre-eclampsia. Participants were predominantly limited to Caucasian women. The lack of an ideal ‘living donor comparator group’ hindered a full quantification (including meta-analysis) of the pregnancy-related complications in LKD.
We identified seven clinical guidelines and consensus statements published since 2010. These were broadly consistent in stating that the risk of pregnancy-related complications in LKD was similar to the general population’s risk, and that potential LKD should be informed of this risk. They were however inconsistent in their scope. For example, only three guidelines recommended enquiring into prior pregnancy-induced complications, and only two offered specific guidance on post-donation pregnancy follow-up. The most striking inconsistency was the differing view as to whether or not women who had not yet completed a family should be accepted as LKD. For example, one guideline stated that ‘women should not be excluded from donation solely on the basis of a desire to have children after donation’, whilst another stated that ‘it seem(ed) advisable to have completed a planned family before donation’.

Conclusion
The relative risk of pregnancy-related complications in LKD increases relative to the risk in non-LKD, though the increase in absolute risk remains very low. Though multiple guidelines for living kidney donation were identified, their advice for women of childbearing age was at times scant and inconsistent. The LKD of the future is likely to differ from the LKD of yesteryear. As such more focus should be placed on better identifying and individualising risk for LKD. Whilst the evidence suggests that an LKD’s risk of complications in pregnancy remains low post donation, one should keep in mind that a potential LKD’s personalised risk is unknown.