Prevalence and determinants of chronic kidney disease in women with hypertensive disorders in pregnancy in Nigeria: a cohort study.

Background: Worldwide, hypertensive disorders in pregnancy (HDPs) complicate between 5 and 10% of pregnancies. Sub-Saharan Africa (SSA) is disproportionately affected by a high burden of HDPs and chronic kidney disease (CKD). Despite mounting evidence associating HDPs with the development of CKD, data from SSA are scarce.

Methods: Women with HDPs (n = 410) and normotensive women (n = 78) were recruited at delivery and prospectively followed-up at 9 weeks, 6 months and 1 year postpartum. Serum creatinine was measured at all time points and the estimated glomerular filtration rates (eGFR) using CKD-Epidemiology equation determined. CKD was defined as decreased eGFR< 60 mL/min/1.73m lasting for ≥ 3 months. Prevalence of CKD at 6 months and 1 year after delivery was estimated. Logistic regression analyses were conducted to evaluate risk factors for CKD at 6 months and 1 year postpartum.

Results: Within 24 h of delivery, 9 weeks, and 6 months postpartum, women with HDPs were more likely to have a decreased eGFR compared to normotensive women (12, 5.7, 4.3% versus 0, 2 and 2.4%, respectively). The prevalence of CKD in HDPs at 6 months and 1 year postpartum was 6.1 and 7.6%, respectively, as opposed to zero prevalence in the normotensive women for the corresponding periods. Proportions of decreased eGFR varied with HDP sub-types and intervening postpartum time since delivery, with pre-eclampsia/eclampsia showing higher prevalence than chronic and gestational hypertension. Only maternal age was independently shown to be a risk factor for decreased eGFR at 6 months postpartum (aOR = 1.18/year; 95%CI 1.04-1.34).

Conclusion: Prior HDP was associated with risk of future CKD, with prior HDPs being more likely to experience evidence of CKD over periods of postpartum follow-up. Routine screening of women following HDP-complicated pregnancies should be part of a postpartum monitoring program to identify women at higher risk. Future research should report on both the eGFR and total urinary albumin excretion to enable detection of women at risk of future deterioration of renal function.