Postnatal assessment for renal dysfunction in women with hypertensive disorders of pregnancy : A prospective observational study.

Background: Hypertensive disorders of pregnancy are associated with chronic kidney disease. Early detection of renal dysfunction enables implementation of strategies to prevent progression. International guidelines recommend review at 6-8 weeks postpartum to identify persistent hypertension and abnormal renal function, but evidence for the efficacy of this review is limited.

Methods: All women attending a specialist fetal-maternal medicine clinic for hypertensive disorders of pregnancy (pre-eclampsia, chronic hypertension, gestational hypertension) were invited for a 6-8 weeks postpartum review of their blood pressure and renal function in order to establish the prevalence and independent predictors of renal dysfunction. Renal dysfunction was defined as low estimated Glomerular Filtration Rate (eGFR < 60 ml/min/1.73 m) or proteinuria (24-h protein excretion > 150 mg or urinary albumin-to-creatinine ratio > 3 mg/mmol). All women attending a specialist clinic for hypertensive disorders were invited for a 6-8 weeks postpartum review of their blood pressure and renal function. Demographics, pregnancy and renal outcomes were prospectively collected.

Results: Between 2013 and 2019, 740 of 1050 (70.4%) women who had a pregnancy complicated by a hypertensive disorder attended their 6-8 weeks postpartum visit. Renal dysfunction was present in 32% of the total cohort and in 46% and 22% of women with and without pre-eclampsia, respectively. Multivariate logistic regression demonstrated that independent predictors were pre-eclampsia, chronic hypertension, highest measured antenatal serum creatinine, highest measured antenatal 24-h urinary protein, and blood pressure ≥ 140/90 mmHg at the postnatal visit.

Conclusions: Renal dysfunction was present in one in three women with hypertensive disorders of pregnancy at 6-8 weeks postpartum. This includes women with gestational hypertension and chronic hypertension without superimposed pre-eclampsia, and thus these women should also be offered postnatal review.