Pregnancy-Related Acute Kidney Injury at High Altitude: A Retrospective Observational Study in a Single Center
Abstract BackgroundPregnancy-related acute kidney injury (Pr-AKI) is associated with maternal and fetal morbidity and mortality. There are few studies focusing on Pr-AKI at high altitude in the literature. Objectivesto investigate the incidence, etiology, clinical features and maternal-fetal outcomes of Pr-AKI in women living at high altitude.Methods6,512 pregnant women attending the Department of Obstetrics&Gynecology at local hospital from January 2015 to December 2018 were screened for Pr-AKI. Patients with serum creatinine above normal range(>70umol/L) then underwent assessment to confirm the diagnosis of Pr-AKI. AKI was diagnosed and staged based on Kidney Disease Improving Global Outcomes(KDIGO) guideline. Individuals meeting the Pr-AKI criteria were recruited. Their clinical data were recorded and retrospectively analyzed. ResultsPr-AKI was identified in 136/6512(2.09%) patients. Hypertensive disorders of pregnancy(HDP) was the leading cause of Pr-AKI(35.3%). 4(2.9%) women died and the majority(86.1%) had recovered renal function before discharge. Fetal outcomes were confirmed in 109 deliveries with gestational age≥20 weeks. Pre-term delivery occurred in 30(27.3%) cases and perinatal deaths in 17(15.5%). The rate of low birth weight infant(LBWI) and intrauterine growth restriction(IUGR) was 22.0% and 10.9% respectively. 16(14.5%) infants were admitted to NICU after birth. Patients with HDP had a higher cesarean rate(56.3%). More IUGR(25.0%) and LBWI(37.8%) were observed in their infants with a higher risk of admission to NICU(22.0%). High altitude might have an adverse impact on HDP-related Pr-AKI patients with earlier terminated pregnancy and more stillbirth/neonatal death. Logistic regression models indicated that uncontrolled blood pressure, high altitude and advanced AKI were associated with adverse fetal outcomes in HDP-related Pr-AKI patients.ConclusionsPr-AKI was not rare in high-altitude regions and caused severe fetal morbidities and mortalities. Uncontrolled blood pressure, high altitude and advanced AKI were all risk factors for adverse fetal outcomes in Pr-AKI patients, especially for those with hypertensive disorders of pregnancy.