Effects of fetal haemoglobin on systemic oxygenation in preterm infants and the development of retinopathy of prematurity PacIFiHER Report No. 2

Background/aimsFetal haemoglobin (HbF) has an oxyhaemoglobin dissociation curve that may affect systemic oxygenation and the development of retinopathy of prematurity (ROP). The study aim is to characterise the effects of HbF levels on systemic oxygenation and ROP development.MethodsProspective study conducted from 1 September 2017 through 31 December 2018 at the Johns Hopkins NICU. Preterm infants with HbF measured at birth, 31, 34 and 37 weeks post-menstrual age (PMA), complete blood gas and SpO2recorded up to 42 weeks PMA, and at least one ROP exam were included.ResultsSixty-four preterm infants were enrolled. Higher HbF was associated with significantly higher SpO2, lower PCO2, lower FiO2from birth to 31 weeks PMA and 31 to 34 weeks PMA (rs=0.51, rs=−0.62 and rs=−0.63; ps=0.71, rs=−0.58 and rs=−0.79; p2was required for HbF in the lowest tercile from birth compared with HbF in the highest tercile to 31 weeks and 31 to 34 weeks PMA; FiO2=35 (21–100) versus 21 (21–30) p2=30 (28–100) versus 21 (21–30) p2, and lower levels of HbF (pConclusionLow HbF levels correlated with poor oxygenation indices and increased risk for ROP. O2saturation goals to prevent ROP may need to incorporate relative amount of HbF.