What is the optimal oxygen saturation for extremely premature infants? A Meta analysis

Objective: To explore an optimal oxygen saturation for extremely preterm infants based on a systemic review of the published studies. Methods: A Meta analysis of the published studies by the NeOProM Group which compared the outcomes of extremely preterm infants (gestational age < 28 weeks) maintained in either a low (85%-89%) or high (91%-95%) oxygen saturation (SpO₂) by using the STATA 12.0. The outcomes measured included the mortality and the incidences of retinopathy of prematurity (ROP), necrotizing enterocolitis of newborn (NEC), broncho-pulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and patent ductus arteriosus (PDA). Results: Three studies were included, in which 2 460 infants were assigned into the low SpO₂ group and 2 459 infants in the high SpO₂ group. The Meta analysis demonstrated that the risk of mortality before discharge or at the age of 18 months increased in the low SpO₂ group compared with the high SpO₂ group (RR: 1.19; 95%CI: 1.05-1.35); the risk of ROP decreased in the low SpO₂ group (RR: 0.73; 95%CI: 0.53-1.00); the risk of NEC increased in the low SpO₂ group (RR: 1.26; 95%CI: 1.06-1.49). There was no significance in the incidences of BPD, IVH and PDA between the two groups. Conclusions: Maintaining SpO₂ at 85%-89% may decrease the incidence of ROP, but increase the mortality rate and the incidence of NEC in extremely premature infants.