Maternal Preconception Serum Alanine Aminotransferase Levels and Risk of Preterm Birth among Reproductive-Aged Women - China, 2013-2017.

What is already known about this topic?:The significance of maternal liver health concerning preterm birth (PTB) is well recognized; however, there is a gap in understanding the precise influence of preconception serum alanine aminotransferase (ALT) levels on the risk of PTB. What is added by this report?:In this retrospective cohort study, a J-shaped relationship between preconception serum ALT levels and risk of PTB was observed, indicating that both significantly elevated and decreased ALT levels may contribute to the risk. What are the implications for public health practice?:Maintaining optimal preconception serum ALT levels may reduce the risk of PTB, thereby informing specific preventive measures for women of reproductive age.