Women who donate a kidney are almost two and a half times more likely than are nondonors to have preeclampsia or gestational hypertension in pregnancy, according to a study presented at Kidney Week 2014 and published online simultaneously in the New England Journal of Medicine.
“Information on this potential risk should be included in clinical practice guidelines, shared in the informed-consent processes for potential donors and their recipients when a woman has reproductive potential, and used to guide the care of pregnant donors,” wrote the study authors, led by Dr. Amit X. Garg at the London Kidney Research Unit in London, Ont. (N. Engl. J. Med. 2014 Nov. 14 [doi:10.1056/NEJMoa1408932]).
The Canadian retrospective study matched 85 living kidney donors in a 1:6 ratio with 510 healthy nondonors and followed them for almost 11 years. During this time, 131 pregnancies occurred in the donor group and 788 in the nondonor group.
Gestational hypertension or preeclampsia was diagnosed in 15 donors and 38 nondonors (11% vs. 5%, odds ratio for donors, 2.4; 95% confidence interval, 1.2 to 5.0; P = .01), the investigators reported.
No significant differences were observed between groups for other maternal or fetal outcomes, and there were no maternal or perinatal deaths in the study that was part of the Donor Nephrectomy Outcomes Research Network (DONOR).
However, they noted that the study included limitations, such as not recording body mass index, medication use, or the race of study participants.
Confidence intervals for risk estimates also were wide, and physicians used clinical judgment when applying accepted diagnostic criteria for gestational hypertension and preeclampsia.
“It remains possible that gestational hypertension and preeclampsia were more likely to be diagnosed and recorded among donors than nondonors despite similar clinical presentations in two groups,” the investigators wrote.
“There may be a role for government programs to cover the costs of recommended pregnancy care for donors who lack health insurance, including any costs related to the treatment of hypertension,” they added.
The meeting was sponsored by the American Society of Nephrology. The study was supported by a grant from the Canadian Institute of Health Research as well as several other research institutions. Dr. Garg received grants from Astellas and Roche outside this study. Several other authors received grants from a number companies outside this study, while the remainder of the authors had no relevant disclosures.