A nationwide register-based cohort study examined the association between preeclampsia in mothers and the risk of kidney disease in their offspring.

INTRODUCTION Women with preeclampsia often deliver preterm (under37 weeks gestation). Preterm birth is associated with an increased risk of offspring kidney disease, but whether preeclampsia is independently associated with kidney disease risk is unknown. Here, we conducted a register-based cohort study to explore associations between maternal preeclampsia and offspring kidney disease after accounting for preterm birth. METHODS Using Cox regression, we estimated hazard ratios (HRs) comparing kidney disease rates, overall and by subtype, in offspring with and without exposure to maternal preeclampsia. RESULTS The study included 2,288,589 persons born in Denmark 1978-2017 of whom 63,191 were exposed to preeclampsia; 37,782 individuals developed kidney disease during 43,137,193 person-years of follow-up. Offspring exposed to preeclampsia and born at term (37 or more weeks' gestation) were 26% more likely than offspring born at term but not exposed to preeclampsia to develop kidney disease in infancy (HR 1.26, 95% confidence interval [1.09-1.46]), and had increased rates of all kidney disease subtypes except acute kidney disease after one year of age (HR range 1.11 to 1.88). Associations between term preeclampsia and offspring chronic, and unspecified and diabetic kidney disease were strongest after 25 years of age (HRs 1.36, 1.70 and 2.85, respectively). Conversely, there was little evidence that exposure to preeclampsia with preterm delivery was associated with increased rates of offspring kidney disease beyond the first year of life (under 1 year: 1.41, [1.05-1.90]; one year or more: 0.94, [ 0.79- 1.11]). CONCLUSIONS Associations of maternal term preeclampsia with offspring kidney disease hint at underlying mechanisms different from those potentially explaining established associations with preterm birth.