Abnormal alanine aminotransferase levels in patients with moderate or severe ovarian hyperstimulation result in an increased risk of obstetric complications.

Objectives: To explore the effect of abnormally elevated serum alanine aminotransferase (ALT) on pregnancy outcomes in patients with moderate and severe ovarian hyperstimulation syndrome (OHSS) at disease onset. Methods: This was a single‐center retrospective cohort study conducted between January 1, 2014 and October 31, 2021. A total of 3550 fresh in vitro fertilization/intracytoplasmic sperm injection embryo transfer cycles were included, using Golan's three‐degree, five‐level classification to diagnose patients with OHSS. According to the patient's ALT level after diagnosis of OHSS, 123 (3.46%) patients with moderate‐to‐severe OHSS were divided into two groups. A control group included 3427 (96.54%) non‐OHSS patients, and 91 (2.56%) abnormal ALT patients were matched with the control group for propensity scores. Results: There was no difference in baseline data between the abnormal ALT and matched control groups. The incidence of obstetric complications was significantly higher in the abnormal ALT group than in the matched control group (P < 0.05). After adjusting for confounding factors, the incidence of obstetric complications in the abnormal ALT group was still higher than that in the normal ALT group (P < 0.05). Conclusion: In patients with moderate and severe OHSS, higher ALT levels resulted in an increased risk of obstetric and neonatal complications. Synopsis: Abnormally elevated ALT in patients with moderate and severe OHSS during the pathogenesis of OHSS can result in an increased risk of obstetric complications. [ABSTRACT FROM AUTHOR]