The impact of disparities in social determinants of health on adverse neonatal outcomes among women with gestational diabetes mellitus: The role of gestational weight gain trajectories in a multicenter cohort

Disparities in multidimensional social determinants of health (SDOH) significantly exacerbate the risk of adverse neonatal outcomes among women with gestational diabetes mellitus (GDM). While optimal gestational weight gain (GWG) is a critical, modifiable determinant of perinatal health, its role in linking structural social vulnerabilities to neonatal complications remains unclear. This multicenter cohort study aimed to evaluate whether longitudinal GWG trajectories may partly account for the association between SDOH profile and adverse neonatal outcomes. In this multicenter cohort of women with GDM, SDOH profile was assessed as the primary exposure, GWG trajectories as a dynamic weight-management phenotype, and composite adverse neonatal outcome as the outcome. Multivariable logistic regression was used to examine the associations of SDOH profile and GWG trajectories with composite adverse neonatal outcomes, whereas multinomial logistic regression was used to assess the association between SDOH profile and GWG trajectory membership. Mediation analysis, interaction analysis, body mass index (BMI)-stratified analyses, and sensitivity analyses excluding women with pre-existing endocrine disorders were also performed. Among 1,916 women with GDM, 482 neonates (25.2%) experienced a composite adverse neonatal outcome. The disadvantaged versus advantaged SDOH profile was associated with adverse neonatal outcomes (aOR 1.703, 95% CI 1.314–2.214) and high GWG trajectory membership (aRRR 2.162, 95% CI 1.560–2.997. High GWG trajectory was associated with adverse neonatal outcomes (aOR 2.196, 95% CI 1.660–2.902). Mediation analysis estimated that 25.6% of the association may be accounted for through GWG trajectories. Among women with GDM, the disadvantaged SDOH profile was associated with higher neonatal risk and a greater likelihood of high GWG trajectory membership. GWG trajectories may partly account for SDOH-related differences in neonatal outcomes, supporting more equitable, risk-stratified GDM care.