Objective: We examined the predictive macrosomia birthweight thresholds for adverse maternal and neonatal outcomes.
Study design: This was a multicenter, retrospective cohort study conducted in China. We selected 178 709 singletons weighing ≥2500 g with gestational age 37-44 weeks. We categorized macrosomia with two gradations (4000-4499 g and ≥4500 g) and compared them with a normosomic reference group of infants with birthweight 2500-3999 g.
Results: The risks of obstetric and neonatal complications increased when infants had a birthweight of ≥4000 g. The rates of infant mortality, Apgar score ≤3 at 5 min, respiratory and neurological disorders rose significantly among neonates weighing ≥4500 g.
Conclusion: A definition of macrosomia as birthweight ≥4000 g could be beneficial as an indicator of obstetric and newborn complications, and birthweight ≥4500 g might be predictive of severe infant morbidity and mortality risk.
Keywords: Birthweight; macrosomia; outcome; threshold.