Elevated maternal serum aminotransferase in early pregnancy associated with early-onset preeclampsia: A cohort study of 116,967 pregnancies in Shanghai, China

Preeclampsia (PE) is a severe pregnancy-specific complications along with multiple organ impairment. However, whether women with elevated serum aminotransferase levels in early pregnancy are susceptible to PE, and even early-onset PE remains unclear. A hospital-based retrospective cohort study involving 116,967 pregnant women delivered between 2014 and 2022 in Shanghai, China was conducted. The study employed restricted cubic splines and logistic regression analysis to investigate the associations between early maternal liver function tests, specifically alanine aminotransferase (ALT), aspartate aminotransferase (AST), and the ALT/AST ratio, and the risk of PE and its subtypes, including early-onset preeclampsia (occurred at 40 IU/L) in early pregnancy were associated with an increased risk of PE (adjusted odds ratio (aOR) = 1.57 95% confidence interval (CI): 1.38–1.80), early-onset PE (aOR = 1.78 95% CI: 1.27–2.48) and late-onset PE (aOR = 1.53 95% CI: 1.33–1.76). Increased risks of PE and early-onset PE were also observed in pregnant women with AST levels > 40 IU/L (aOR = 1.63 95% CI: 1.33–1.99 for PE; aOR = 1.81 95% CI: 1.09–3.00 for early-onset PE ) or ALT/AST ratio > 1 (aOR = 1.36 95% CI: 1.25–1.47 for PE; aOR = 1.66 95% CI: 1.34–2.06 for early-onset PE). Furthermore, women with abnormal ALT or AST levels in early pregnancy but relieved in later pregnancy periods still had elevated risks of PE and early-onset PE. The stratified analysis demonstrated that women with advanced age complicated with high ALT have increased risk of developing early-onset PE. Elevated levels of ALT, AST and their ratios in early pregnancy were associated with an increased risk of PE, especially early-onset PE. Therefore, screening for aminotransferase levels in early pregnancy could be considered for identification of women at high risk of developing liver dysfunction-related PE, or even early-onset PE.