Pregnancy-Related Acute Kidney Injury in Preeclampsia: Risk Factors and Renal Outcomes.

Preeclampsia is a common cause of acute kidney injury (AKI) in low- and middle-income countries, but AKI incidence in preeclampsia, its risk factors, and renal outcomes are unknown. A prospective observational multicenter study of women admitted with preeclampsia in South Africa was conducted. Creatinine concentrations were extracted from national laboratory databases for women with maximum creatinine of ≥90 μmol/L (≥1.02 mg/dL). Renal injury and recovery were defined by Kidney Disease Improving Global Outcomes creatinine criteria. Predefined risk factors, maternal outcomes, and neonatal outcomes were compared between AKI stages. Of 1547 women admitted with preeclampsia 237 (15.3%) met AKI criteria: 6.9% (n=107) stage 1, 4.3% (n=67) stage 2, and 4.1% (n=63) stage 3. There was a higher risk of maternal death (n=7; relative risk, 4.3; 95% CI, 1.6-11.4) and stillbirth (n=80; relative risk, 2.2; 95% CI, 1.8-2.8) in women with AKI compared with those without. Perinatal mortality was also increased (89 of 240; 37.1%). Hypertension in a previous pregnancy was the strongest predictor of AKI stage 2 or 3 (odds ratio, 2.24; 95% CI, 1.21-4.17). Renal recovery rate reduced with increasing AKI stage. A third of surviving women (76 of 230 [33.0%]) had not recovered baseline renal function by discharge. Approximately half (39 of 76; 51.3%) of these women had no further creatinine testing post-discharge. In summary, AKI was common in women with preeclampsia and had high rates of associated maternal and perinatal mortality. Only two-thirds of women had confirmed renal recovery. History of a previous hypertensive pregnancy was an important risk factor.