Risk factors and outcomes associated with pregnancy-related acute kidney injury in a high-risk cohort of women in Nigeria.

Introduction: Despite a decline in developed countries, pregnancy-related acute kidney injury (PRAKI) remains a significant contributor to maternal mortality and adverse fetal outcomes in resource-constrained settings. Little is known about the impact of pregnancy-related acute kidney injury in Nigeria. Therefore, this study aimed to assess the incidence and maternal-fetal outcomes associated with pregnancy-related acute kidney injury among a cohort of high-risk women in Nigeria.

Methods: This prospective multicenter study included women at high risk of acute kidney injury, who were more than 20 weeks pregnant or within 6 weeks postpartum and admitted to the Obstetrics and Gynecology units of two large public hospitals between September 1, 2019, and July 31, 2022. Acute kidney injury was defined and classified using the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results: A total of 433 women, with mean age (± standard deviation) of 28 ± 6 years, were included in the evaluation. Pregnancy-related acute kidney injury occurred in 113 women (26.1%; 95% confidence interval [CI]: 21.1%-30.2%). The leading cause was preeclampsia (n = 57; 50.1%); 19 women died (4.4%), with 17 deaths (15%) occurring in the PRAKI group. Increasing severity of pregnancy-related acute kidney injury was independently associated with maternal mortality: adjusted odds ratio (aOR) for KDIGO stage 2 = 4.40; 95% CI 0.66-29.34, p = 0.13, and KDIGO stage 3 aOR = 6.12; 95% CI 1.09-34.34, p = 0.04. The overall perinatal mortality was 15% (n = 65), with 28 deaths (24.8%) occurring in the PRAKI group. Pregnancy-related acute kidney injury was also associated with an increased risk of perinatal mortality, aOR = 2.23; 95 CI 1.17-4.23, p = 0.02.

Conclusions: The incidence of pregnancy-related acute kidney injury was high, and significantly associated with maternal and perinatal mortality. The leading causes were hypertensive disorders of pregnancy.