Pregnancy-related Acute Kidney injury (PrAKI): an observational study of 500 cases from a public hospital in South India.

Background: Pregnancy-related acute kidney injury (PrAKI) is a global issue with a significant impact on the society. High maternal and fetal mortality are reported with PrAKI. AKI can occur during antepartum or postpartum periods. In low-middle-income countries, common causes of PrAKI are sepsis and preeclampsia. We undertook this study to analyze the epidemiology and outcomes of pregnancy-related acute kidney injury in our region.

Methods: This is a retrospective study analyzing 500 cases of PrAKI between 2014 and 2024 in a tertiary care referral public hospital. The setting was Gandhi Medical College, Hyderabad, Telangana, India. Our center is a tertiary care, multidisciplinary hospital with dedicated maternal-child health facilities, with a total of 200 beds in a dedicated area with an exclusive maternal intensive care unit, where we provide bedside dialysis services. Referrals are from the whole state, which has a population of 40 million inhabitants, and from adjacent states. Data were collected from electronic case records. Incomplete case records were excluded from the study. We collected epidemiological data, clinical presentation, causes of PrAKI and the outcomes, and analyzed the epidemiology, etiology, and maternal and fetal outcomes of PrAKI. The study population included all pregnant patients referred for kidney services.

Results: We included sequential cases of PrAKI referred between 2014 and 2024. The total number of patients included in the study was 500 after exclusion of incomplete records. The mean age of the patients was 25 ± 4 years. Most PrAKI were observed in the postpartum period 280/500 (56%), and 220 cases were antepartum (44%), of whom 188/220 cases presented in the third trimester. Only four patients had first-trimester PrAKI (0.8%), and 28 patients presented in the second trimester (5.6%). The majority of cases were in the third trimester and postpartum (93.6%). We grouped causes of PrAKI into four categories: preeclampsia, sepsis, the combination of preeclampsia and sepsis, and others. The preeclampsia group included 103 patients (20.6%), 129 patients (25.8%) were in the sepsis group, while the combination of preeclampsia and sepsis group included 169 patients (33.8%). Other causes included drugs, isolated postpartum hemorrhage, isolated abruption, and isolated Hemolysis, Elevated Liver enzymes, and Low Platelet counts (HELLP) syndrome. Antepartum hemorrhage was noted in 44% of cases, with isolation occurrence in 35 patients (7%), in combination with preeclampsia, sepsis, and preeclampsia + sepsis in 34.7%. Similarly, postpartum hemorrhage was seen in 39 patients (7.8%), with isolation occurrence in 19/500 (3.8%) and a combination occurrence in 20 patients (4%). About 102 patients had HELLP syndrome (20.4%). Isolated hemolysis was observed in 8/500 (1.6%) and, the combination with either preeclampsia/sepsis/both, was seen in 94 patients (18.8%). We diagnosed pregnancy-related thrombotic microangiopathy in 7/500 patients (1.4%). We could biopsy only 12 patients with diffuse cortical necrosis, patchy cortical necrosis, thrombotic microangiopathy, and acute tubular necrosis. Maternal mortality was 24% and fetal mortality was 45% in our study cohort.

Conclusion: Pregnancy-related acute kidney injury is a major health concern with diverse etiologies including preeclampsia and sepsis. With an incidence of 7.6%, AKI in pregnancy is associated with high maternal and fetal mortality in our area. Both early referral and strengthening obstetric care services would improve the outcomes of PrAKI.