Outcomes of obstetric versus non-obstetric acute kidney injury: insights from an Indian tertiary care centre.

Abstract

Background: Pregnancy-related Acute kidney injury (PR-AKI) accounts for approximately 15% of maternal mortality, with 10-30% progressing to end stage renal disease (ESRD). However, there are no comparative studies of obstetric and non-obstetric AKI. This study compares the outcomes of both groups with short-term follow-up to day 90.

Materials and methods: This prospective observational study was conducted over 1.5 years, enrolling 260 cases divided into non-obstetric and obstetric AKI groups.

Inclusion criteria: Non-obstetric group - patients > 18 years with AKI; Obstetric group - pregnant or up to 42 days postpartum with AKI, as per KDIGO criteria. Patients with known Chronic kidney disease (CKD) or transplant were excluded. Demographics, clinical profiles and relevant investigations (including renal biopsy) were analysed. Outcomes assessed at days 7, 30, and 90 for complete recovery, dialysis dependency, CKD progression, and mortality.

Results: Of 260 patients, 83.4% were in non-obstetric group while 16.6% were in the obstetric group. Sepsis was leading cause of AKI (51.5%), affecting 47.7% of non-obstetric and 74.4% of obstetric patients. Renal biopsies (12.3% of cases) predominantly showed acute tubular injury, lupus nephritis, Minimal change disease, Focal segmental glomerulosclerosis, ANCA-associated Glomerulonephritis (GN), IgA nephropathy, and Membranoproliferative GN. In Obstetric AKI, acute cortical necrosis and thrombotic microangiopathy (TMA) were common biopsy findings. At 3-months follow-up, complete recovery was higher in the non-obstetric group (40.5% vs. 33.3%), with the obstetric group having more progression to CKD and dialysis dependency. Mortality was higher in non-obstetric AKI (50.4% vs. 33.3%), likely due to underlying comorbidities.

Conclusion: Non-obstetric AKI showed higher early mortality but better long-term recovery, while obstetric AKI had poorer renal outcomes and a higher risk of progression to CKD. Early detection and intervention are critical for improving outcomes.