Birth weight, neonatal care, and infant mortality: Evidence from macrosomic babies

This study demonstrates that rule-of-thumb health treatment decision-making exists when assigning medical care to macrosomic newborns with an extremely high birth weight and estimates the short-run health return to neonatal care for infants at the high end of the birth weight distribution. Using a regression discontinuity design, we find that infants born with a birth weight above 5000-gram have a 2 percentage-point higher probability of admission to a neonatal intensive care unit and a 1 percentage-point higher probability of antibiotics receipt, compared to infants with a birth weight below 5000-gram. We also find that being born above the 5000-gram cutoff has a mortality-reducing effect: infants with a birth weight larger than 5000-gram face a 0.15 percentage-point lower risk of mortality in the first week and a 0.20 percentage-point lower risk of mortality in the first month, compared to their counterparts with a birth weight below 5000-gram. We do not find any evidence of changes in health treatments and mortality at macrosomic cutoffs lower than 5000-gram, which is consistent with the idea that such treatment decisions are guided by the higher expected morbidity and mortality risk associated with infants weighing more than 5000-gram.