Association between maternal serum RANKL and adverse birth outcomes: a prospective cohort study

BACKGROUND: Adverse birth outcomes remain a global public health issue. RANKL participates in immune regulation and bone metabolism, but its association with adverse birth outcomes has not been fully clarified. OBJECTIVE: To explore the association between maternal mid-pregnancy serum RANKL levels and adverse birth outcomes (PTB, BD, SGA, LGA, LBW, macrosomia). METHODS: This was a cross-sectional study conducted in South China. Maternal serum samples were collected during the second trimester (13-20 gestational weeks). Serum RANKL levels were measured, and logistic regression and restricted cubic spline analyses were used to evaluate the associations. RESULTS: Maternal mid-pregnancy serum RANKL levels were significantly positively associated with SGA. ROC analysis suggested that serum RANKL had a certain discriminatory ability for SGA and LBW. CONCLUSION: Mid-pregnancy maternal serum RANKL levels are associated with an increased risk of SGA. Serum RANKL may serve as a potential indicator for risk assessment of adverse birth outcomes. These findings provide new clues for understanding the aetiology of adverse birth outcomes.