Objective: To follow-up children who had been resuscitated at birth with either 21% or 100% oxygen (O2).
Methods: A multicenter study with 10 participating centers recruited 609 infants to the Resair 2 study where resuscitation was performed with either 21% or 100% O2. A follow-up between ages 18 and 24 months was performed. However, during follow-up registration, it was found that 18 infants had been enrolled twice in the original Resair 2 study with different registration numbers, leaving 591 enrolled in the Resair 2 study and 410 enrolled in the 7 centers participating in the follow-up. Of these 410 infants, 79 died (76 in the neonatal and 3 in the postneonatal period). Furthermore, for 8 infants informed consent was not obtained, leaving 323 eligible for follow-up. Of these, 213 infants (66%) were followed-up: 91 (62%) had been resuscitated with 21% O2, and 122 (69%) with 100% O2. At a median age of 22 and 20 months (not significant) in the 21% and 100% groups, respectively, a simple questionnaire was filled out and neurologic assessment was performed in addition to measuring anthropometric data.
Results: There were no significant differences in weight, height, or head circumference between the 2 groups. Cerebral palsy developed in 10% and 7%, respectively, in the 2 groups (not significant). In total, 11 cases (12%) in the 21% versus 11 cases (9%) in the 100% O(2) group (odds ratio: 1.39, 95% confidence interval: 0.57-3.36) developed cerebral palsy and/or mental or other delay. Furthermore, it was concluded that 14 (15%) in the 21% group and 12 (10%) in the 100% group were not normal (odds ratio: 1.67, 95% confidence interval: 0.73-3.80).
Conclusions: There were no significant differences in somatic growth or neurologic handicap at an age of 18 to 24 months in infants resuscitated with either 21% or 100% O2 at birth. Based on these data, resuscitation with ambient air seems to be safe, at least in most cases. More studies are needed to settle this issue.