Incidence, aetiology and outcomes of obstetric-related acute kidney injury in Malawi: a prospective observational study

William R. Cooke, Ulla K. Hemmilä, Alison L. Craik, Chimwemwe J. Mandula, Priscilla Mvula, Ausbert Msusa, Gavin Dreyer, Rhys Evans

Obstetric-related acute kidney injury (AKI) is thought to be a key contributor to the overall burden of AKI in low resource settings, causing significant and preventable morbidity and mortality. However, epidemiological data to corroborate these hypotheses is sparse. This prospective observational study aims to determine the incidence, aetiology and maternal-fetal outcomes of obstetric-related AKI in Malawi. Women greater than 20 weeks gestation or less than 6 weeks postpartum admitted to obstetric wards at a tertiary hospital in Blantyre, Malawi, and at high-risk of AKI were recruited between 21st September and 11th December 2015. All participants had serum creatinine tested at enrolment; those with creatinine above normal range (> 82 μmol/L) underwent serial measurement, investigations to determine cause of kidney injury, and were managed by obstetric and nephrology teams. AKI was diagnosed and staged by Kidney Disease Improving Global Outcomes (KDIGO) criteria. Primary outcomes were the incidence proportion and aetiology of AKI. Secondary outcomes were in-hospital maternal mortality, need for dialysis, renal recovery and length of stay; in-hospital perinatal mortality, gestational age at delivery, birthweight and Apgar score. 354 patients were identified at risk of AKI from the approximate 2300 deliveries that occurred during the study period. Three hundred twenty-two were enrolled and 26 (8.1%) had AKI (median age 27 years; HIV 3.9%). The most common primary causes of AKI were preeclampsia/eclampsia (n = 19, 73.1%), antepartum haemorrhage (n = 3, 11.5%), and sepsis (n = 3, 11.5%). There was an association between preeclampsia spectrum and AKI (12.2% AKI incidence in preeclampsia spectrum vs. 4.3% in other patients, p = 0.015). No women with AKI died or required dialysis and complete renal recovery occurred in 22 (84.6%) cases. The perinatal mortality rate across all high-risk admissions was 13.8%. AKI did not impact on maternal or fetal outcomes. The incidence of AKI in high-risk obstetric admissions in Malawi is 8.1% and preeclampsia was the commonest cause. With tertiary nephrology and obstetric care the majority of AKI resolved with no effect on maternal-fetal outcomes. Maternal-fetal outcomes in Sub-Saharan Africa may be improved with earlier detection of hypertensive disease in pregnancy.