Maternal smoking during pregnancy and gestational diabetes mellitus: Interactions and independent associations on pregnancy duration and perinatal outcomes

Both GDM and maternal smoking contribute independently to adverse perinatal outcomes, but their combined exposure elevates absolute risks more than either factor alone, particularly for reduced gestational length, preterm birth, and delayed newborn discharge. These findings highlight the importance of addressing both smoking and GDM in prenatal care, even among generally low-risk primiparous women.