Acute kidney injury during pregnancy and puerperium: a retrospective study in a single center

Background: Acute kidney injury (AKI) is rare in women during pregnancy and puerperium, however, it is related to increased morbidity and mortality rates. Objective: The aim of this study was to investigate the incidence, characteristics, and outcomes of AKI during pregnancy and puerperium in a Chinese population. Methods: In this study, pregnant women discharged from hospital between January 2008 and June 2015 were screened. AKI was defined if the level of serum creatitine > 70.72umol/l in pregnant women without chronic kidney disease (CKD). Acute-on-CKD was defined as a 50% increase in the level of serum creatinine vs baseline in patients with pre-existed CKD. Results: We reported a high incidence ( 0.81%) of AKI during pregnancy and puerperium. Three hundred and forty three cases of AKI during pregnancy and puerperium included 21 severe AKI cases and 21 cases with acute-on-CKD. Pre-eclampsia/eclampsia, and postpartum hemorrhage were the most frequent causes of AKI during pregnancy and puerperium. About 17% women with pre-eclampsia/eclampsia and 60% women with HELLP syndrome complicated with AKI. The maternal outcome was good except in the setting of amniotic fluid embolism or hemorrhagic shock, whereas the prenatal outcome was relatively poor. Among the 14 death cases, 7 cases received renal replacement therapy. Amniotic fluid embolism and postpartum hemorrhage were the major causes of death in pregnant women with AKI. Conclusion: AKI during pregnancy and puerperium is not as rare as we thought. Pre-eclampsia/eclampsia is the most common cause of AKI during pregnancy and puerperium, however, the outcome of pre-eclampsia-related AKI is good. Amniotic fluid embolism and postpartum hemorrhage are the leading causes of maternal mortality. Severe AKI may predict poor outcome.