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

Abstract

Background Worldwide, hypertensive disorders in pregnancy (HDPs) complicate between 5–10% of pregnancies. Sub-Saharan Africa 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 for one year. Serum creatinine was measured and the estimated glomerular filtration rates(eGFR) using CKD-Epidemiology equation determined. CKD was defined as decreased eGFR<60mL/min/1.73m2 lasting for ≥ three months. Prevalence of CKD at six months and one year after delivery was estimated. Logistic regression analyses were conducted to evaluate predictors of CKD at six months and one year postpartum. Results Within 24 hours of delivery, nine weeks and six 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 six months and one 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 independently predicted occurrence of decreased eGFR at six 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.