Lower Fetal Haemoglobin Levels at 31- and 34-weeks Post Menstrual Age is Associated with the Development of Retinopathy of Prematurity

Abstract

Purpose : Previous studies have suggested that lower mean fetal haemoglobin (HbF) levels is associated with an increased risk for developing retinopathy of prematurity (ROP). Lower HbF levels may lead to high oxygen exposure to the developing retina thereby increasing the risk of acute ROP. In this study, we characterize the temporal relationship of HbF levels and the development of ROP.

Methods : This is a single institution prospective observational cohort study. Pre-term infants (born < 31 weeks gestational age or <1500 g) with HbF measured at birth (cord blood), 31-, 34-, and 37-weeks post-menstrual age (PMA); and at least one ROP exam, were enrolled.

Results : A total of 60 pre-term infants (28 females, 47%) were enrolled. At 31-, 34-, 37- weeks PMA, infants with ROP (mild=Type 2 or less severe and severe=Type 1 ROP) had statistically lower percentages of HbF than infants with no ROP (9.7±2.9 and 28.2±15 vs 67.1±29.6; p<0.0001; 32.5 and 23.3±14.7 vs 60.1±25; p<0.005; 41.6 and 31.9±15.8 vs 60.2±20.0; p<0.0019). Infants with HbF levels in the lowest tercile at 31-weeks PMA were 7.6 times more likely to develop mild and severe ROP (95% CI 2.1 to 24.0, p-value=0.0006) and this risk increased to 12.3 times (95% CI: 2.6-59.0, p-value=0.0017) at 34-weeks PMA.

Conclusions : Low HbF levels at 31- and 34-weeks PMA are associated with significantly increased risk of developing ROP. The decrease in HbF precedes the development of ROP and may be important in its pathogenesis.

This is a 2020 ARVO Annual Meeting abstract.