The association between birthweight 4000 g or greater and perinatal outcomes in patients with and without gestational diabetes mellitus

Objective: The objective of the study was to examine the association between birthweight of 4000 g or greater and perinatal outcomes in women with and without gestational diabetes mellitus (GDM). Study Design: This was a retrospective cohort study of 36,241 singleton pregnancies stratified by the diagnosis of GDM, with presence or absence of birthweight of 4000 g or greater. Outcomes examined included neonatal hyperbilirubinemia, hypoglycemia, respiratory distress syndrome (RDS), shoulder dystocia, and Erb's palsy. χ² tests and multivariable logistic regression analyses were used to control for confounders. Results: In women with GDM, neonates with a birthweight of 4000 g or greater, compared with those with a birthweight of less than 4000 g, had higher frequencies of hypoglycemia (5.3% vs 2.6%; P = .04), RDS (4.0% vs 1.5%; P = .03), shoulder dystocia (10.5% vs 1.6%; P < .001), and Erb's palsy (2.6% vs 0.2%; P < .001). Even without GDM, these outcomes occurred more frequently in infants with birthweight of 4000 g or greater. GDM increases the odds of adverse outcomes associated with birthweight of 4000 g or greater, particularly shoulder dystocia (adjusted odds ratios [aORs], 16.4 [GDM] vs 9.6 [non-GDM] and Erb's palsy (aORs, 41.9 [GDM] vs 6.7 [non-GDM]). Conclusion: Birthweight of 4000 g or greater is associated with a higher incidence of adverse perinatal outcomes such that neonatal providers should be alerted.