Long term effects of gestational hypertension and pre-eclampsia on kidney function: Record linkage study

Abstract

Objective: To assess the long term effects of hypertensive disorders of pregnancy on renal function.

Design: Cohort study where exposure was gestational hypertension or preeclampsia in the first pregnancy. Normotensive women formed the comparison group.

Setting: Aberdeen, Scotland.

Participants: All women with date of birth on or before 30th June 1969 and at least their first singleton delivery recorded in the Aberdeen Maternity and Neonatal Databank.

Methods: Participants were linked to the Renal Biochemistry Register, Scottish Morbidity Records, Scottish Renal Registry and National Register for deaths.

Main outcome measures: Occurrence of chronic kidney disease (CKD) as identified from renal function tests in later life, hospital admissions or death from kidney disease or recorded as receiving renal replacement therapy.

Results: CKD was diagnosed in 7.5% and 5.2% of women who previously had GH and PE respectively compared to 3.9% in normotensive women. The unadjusted odds ratio (95% confidence interval) of having CKD in PE was 2.04 (1.53, 2.71) and that for GH was 1.37 (1.15, 1.65), while the adjusted odds ratio (95% confidence interval) of CKD was 1.93 (1.44, 2.57) and 1.36 (1.13, 1.63) in women with PE and GH respectively. Kaplan-Meier curves of survival time to development of chronic kidney disease revealed that women with preeclampsia were susceptible to kidney function impairment earliest, followed by those with gestational hypertension.

Conclusions: There was an increased subsequent risk of CKD associated with hypertensive disorders of pregnancy. Women with GH and PE were also found to have CKD earlier than normotensive women.

Keywords: Chronic kidney disease; Gestational hypertension; Preeclampsia; Record linkage.