Inhaled nitric oxide in term and near-term infants: Neurodevelopmental follow-up of The Neonatal Inhaled Nitric Oxide Study Group (NINOS)

Background: Inhaled nitric oxide (INO) improved oxygenation and reduced the occurrence of death or extracorporeal membrane oxygenation in term and near-term hypoxic neonates. We report the results of neurodevelopmental follow-up of infants enrolled in the NINOS trial. Methods: Hypoxic infants ≥ 34 weeks' gestation and < 14 days of age were randomized to 20 ppm INO or 100% oxygen as control. Comprehensive neurodevelopmental assessment of survivors occurred at 18 to 24 months of age. Results: A total of 235 infants were enrolled in the original trial. There were 36 deaths, 20 of 121 infants in the control group and 16 of 114 infants in the INO-treated group. Of the 199 surviving infants, 173 (86.9%) were seen for follow-up (88 members of the control group and 85 members of the INO-treated group), and 135 infants were normal (69 [79.3%] members of the control group and 66 [77.6%] members of the INO-treated group). Twenty-two infants had sensorineural hearing loss (12 members of the control group and 10 members of the INO-treated group). Moderate to severe cerebral palsy occurred in 13 infants (7 infants in the control group and 6 infants in the INO-treated group). Mental developmental index scores (87 ± 18.7 in the control group vs 85 ± 21.7 in the INO-treated group) and psychomotor developmental index scores (93.6 ± 17.5 in the control group vs 85.7 ± 21.2 in the INO-treated group) were not different. A total of 29.6% of the control group compared with 34.5% of the INO-treated group had at least one disability. Infants with congenital diaphragmatic hernia, enrolled in a separate but parallel trial, had similar outcomes with a higher incidence of sensorineural hearing loss. Conclusion: Inhaled nitric oxide is not associated with an increase in neurodevelopmental, behavioral, or medical abnormalities at 2 years of age.