Associations of maternal serum transthyretin concentration with pregnancy and birth outcomes

This study aims to explore the association of maternal serum transthyretin (TTR) concentrations with adverse pregnancy and birth outcomes, as well as the variations in TTR concentrations across different gestational weeks in relation to these outcomes.

This retrospective cohort study included 6,584 women who delivered at The Second Affiliated Hospital of Wenzhou Medical University between January 1, 2022 and January 30, 2024. Logistic regression and Restricted cubic spline (RCS) models were applied to evaluate the association between TTR levels and the risk of complications, based on TTR quartile analyses. Locally estimated scatter plot smoothing (LOESS) curves were performed to provide a graphical representation of the relationship between TTR levels and gestational weeks.

Significant negative correlations were observed between maternal TTR levels and the risk of gestational diabetes mellitus (GDM), preeclampsia (PE), liver disease, anemia during pregnancy, and preterm delivery (all P < 0.001). The RCS models revealed a non-linear relationship between TTR levels and maternal comorbidities, including anemia (adjusted OR 0.992 [95% CI 0.990-0.994]; P = 0.017), liver disease (adjusted OR 0.991 [95% CI 0.988-0.994]; P < 0.001), hypothyroidism (adjusted OR 0.999 [95% CI 0.996-1.001]; P = 0.023) and preterm delivery (adjusted OR 0.986 [95% CI 0.983-0.989]; P < 0.001). The LOESS curves indicated a declining trend in TTR concentrations during the third trimester of pregnancy.

Maternal TTR concentrations showed an inverse linear association with the incidence of GDM and PE. Moreover, complex non-linear relationships were identified with TTR levels and comorbidities such as liver disease, anemia, hypothyroidism during pregnancy, and preterm delivery.