Miscarriage-Related Acute Kidney Injury: A Case Report

Junya Kojima,1 Masanori Ono,1 Koichiro Tasaki,2 Takeshi Nagai,2 Toshitaka Nagao,2 Sho Rinno,3 Yoshihiko Kanno,3 Rie Yoshida,1 Tomoo Suzuki,1 Naoaki Kuji,1 Hirotaka Nishi1 1Department of Obstetrics and Gynecology, Tokyo Medical University, Tokyo, Japan; 2Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan; 3Department of Nephrology, Tokyo Medical University, Tokyo, JapanCorrespondence: Masanori Ono, Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1, Nishishinjuku, Shinjuku, Tokyo, 160-0023, Japan, Tel +81-3-3342-6111, Email masaoriono@gmail.comBackground: Pregnancy-related acute kidney injury (Pr-AKI) is associated with significant maternal and fetal morbidity and mortality, with a three- to four-fold increase in perinatal mortality. Pr-AKI can arise from various obstetric complications, such as hyperemesis gravidarum, septic abortion, hypertensive disorders of pregnancy, pyelonephritis, and antiphospholipid antibody syndrome. Therefore, early diagnosis and appropriate intervention, including the identification of the underlying etiology, are important to effectively manage Pr-AKI. Therefore, we report a case of Pr-AKI after early miscarriage in a patient without hyperemesis gravidarum or septic abortion whose renal function gradually improved postoperatively for miscarriage.Case Presentation: A 34-year-old primigravid woman was referred to us for perinatal management at 6 weeks of gestation. Unfortunately, she was diagnosed with miscarriage 1 week later. The patient had no history of hyperemesis gravidarum or septic abortion; however, she developed oliguria, and her serum creatinine and blood urea nitrogen levels were abnormally increased. Consequently, she underwent a renal biopsy to evaluate renal dysfunction, which indicated tubulointerstitial damage. The patient also underwent manual vacuum aspiration for a miscarriage. Postoperatively, her urine output increased, and her renal function improved. She was determined to have experienced Pr-AKI due to her miscarriage.Conclusion: Our patient had Pr-AKI after a miscarriage in the absence of other causes. This case report highlights the presence of unknown causes of Pr-AKI, warranting further research for the development of preventive interventions.Keywords: pregnancy-related acute kidney injury, miscarriage, missed abortion, creatinine, renal insufficiency