Oxygen-saturation targets and outcomes in extremely preterm infants

Physiological studies have shown that chronic hypoxemia may occur in preterm infants who require supplemental oxygen for extended periods and that this hypoxemia may contribute to poor growth and development. Anecdotal reports and uncontrolled observational studies have suggested that a higher oxygen-saturation range may be beneficial in terms of growth and development.

We conducted a multicenter, double-blind, randomized, controlled trial involving 358 infants born at less than 30 weeks of gestation who remained dependent on supplemental oxygen at 32 weeks of postmenstrual age. They were randomly assigned to a target functional oxygen-saturation range of either 91 to 94 percent (standard-saturation group) or 95 to 98 percent (high-saturation group); this target was maintained for the duration of supplemental-oxygen therapy. The primary outcomes were growth and neurodevelopmental measures at a corrected age of 12 months.

There were no significant differences between the groups in weight, length, or head circumference at a corrected age of 12 months. The frequency of major developmental abnormalities also did not differ significantly between the standard-saturation group and the high-saturation group (24 percent and 23 percent, respectively, P=0.85). There were six deaths due to pulmonary causes in the high-saturation group and one such death in the standard-saturation group (P=0.12). The high-saturation group received oxygen for a longer period after randomization (median, 40 days vs. 18 days; P<0.001) and had a significantly higher rate of dependence on supplemental oxygen at 36 weeks of postmenstrual age and a significantly higher frequency of home-based oxygen therapy.

Targeting a higher oxygen-saturation range in extremely preterm infants who were dependent on supplemental oxygen conferred no significant benefit with respect to growth and development and resulted in an increased burden on health services.