#4762 pregnancy-related acute kidney injury: 10-year series of a nephro-obstetric clinic

Abstract Background and Aims Pregnancy-related acute kidney injury (P-AKI) is a rare complication of pregnancy associated with significant maternal and fetal morbidity and mortality. Its incidence has progressively decreased worldwide with the improvement of obstetric care, but recently some developed countries have noticed an increase in its incidence. Adjusted definition of AKI in pregnancy is lacking, making its incidence difficult to ascertain. Herein, the authors retrospectively evaluated the causes and outcomes of P-AKI patients surveilled by the nephro-obstetric clinical team. Method Retrospective analysis of maternal, obstetric and perinatal outcomes of P-AKI patients, that were followed by the Nephro-obstetric clinical team between 2011 and 2022. Results We evaluated 29 patients, with mean age of 32 ± 6 years [17 – 42], 19 Caucasian and 9 Black, 17 nulliparous, 16 hypertensive, 7 diabetic, 1 with HIV, and 1 with systemic lupus erythematosus. Only 12 patients had CKD and 3 were renal transplant patients. In 2/29 patients P-AKI occurred before 20 weeks [15-17] due to obstructive uropathy and pregnancy hyperfiltration in a CKD G3 patient. After 20 weeks of gestation, P-AKI occurred in 27/29 patients (mean 32 weeks; range 21-41weeks), with mean SCr of 3,1 mg/dl [1,8-4,5] in previously CKD patients and mean SCr of 2.4mg/dl (1,2-58mg/dl) in the patients with normal renal function. Regarding the severity of P-AKI, 16/7/6 patients developed AKI stage 1/2/3 (KDIGO), respectively. Causes of P-AKI after 20 weeks in patients with normal renal function were preeclampsia (PE; 8/14), HELLP syndrome (1/14), hemolytic uremic syndrome (1/14), sepsis (3/14), renal obstruction (1/14), severe hypercalcemia (1/14), cortical necrosis due to hemorrhagic shock (2/14), hypovolemia and nephrotoxic agents (1/14). All patients had full renal recovery. In renal transplant patient P-AKI was related to PE (2/3), sepsis (1/3) and probable calcineurin inhibitor toxicity (1/3). Regarding CKD patients, P-AKI was caused by PE (6/10), hyperfiltration of pregnancy (3/10) and allergic interstitial nephritis (1/10). The need for renal replacement therapy occurred in 7/29, and only 2/7 became dialysis dependent (both with previous CKD diagnosis). De novo or worsening proteinuria occurred in 15/29 (3975 g/day; 431-14000 g/day) and 10/29 patients (mean 6227 mg/day; 681-14937 mg/day), respectively. Regarding fetal outcomes, there were 2 stillbirths, mean gestation duration was 33 weeks (25-41weeks), mean birth weight 1947 g (550-3950 g) and mean Apgar 1/5/10 was 8/9/10, respectively. Cesarean was performed in 19/27 patients and 7 newborns were admitted to the neonate care unit due to prematurity. Conclusion In a tertiary referral center, P-AKI was associated to a wide range of causes, frequently required a multidisciplinary approach and was associated to significant worse maternal, obstetric and perinatal outcomes.