Hyperphagia, a classical feature of neonatal drug withdrawal, has been reported not to lead to excessive weight gain, but this is contrary to our clinical experience. The aim of this study was to determine whether infants with neonatal drug withdrawal suffered excessive weight gain because of hyperphagia and, if so, to determine the risk factors. The study population comprised 48 infants consecutively admitted to the neonatal intensive care unit, 11 of whom gained weight by more than 20 g kg(-1) d(-1) for at least 10 d (excessive weight gain). All 11 infants were hyperphagic (>200 ml/kg) for at least part of the excessive weight gain period. During the perinatal period, the 11 infants had a greater fluid intake (p < 0.01) but similar weight gain to gestational-age-matched, neonatal drug-withdrawal infants who did not suffer any excessive weight gain. Compared to the rest of the cohort, the infants with excessive weight gain were more likely to require treatment with morphine/chlorpromzaine (p < 0.05) and had a higher maximum withdrawal score (p < 0.01).
Conclusion: Hyperphagia can lead to excessive weight gain in infants with neonatal drug withdrawal. Our results suggest that hyperphagia occurs in those who require treatment for severe withdrawal.