Low fetal haemoglobin levels linked to a higher risk of retinopathy of prematurity, study finds

The oxyhaemoglobin dissociation curve of fetal haemoglobin (HbF) may affect systemic oxygenation and the development of retinopathy of prematurity (ROP). The study aims to determine the effects of HbF levels on systemic oxygenation and ROP development.

The prospective study called PaclFiHER Report conducted at the Johns Hopkins NICU enrolled 64 preterm infants with HbF measured at birth, 31, 34, and 37 weeks post-menstrual age (PMA), complete blood gas and SpO2 recorded up to 42 weeks PMA, and at least one ROP exam.

The study had the following key takeaways:

1. The results showed higher HbF levels were associated with significantly higher SpO2 and lower PCO2, and FiO2 from birth to 31 weeks PMA and 31 to 34 weeks PMA.
2. Higher median FiO2 was required for HbF in the lowest tercile from birth to 31 weeks and 31 to 34 weeks PMA to maintain oxygen saturation goals set by the neonatal intensive care unit.
3. Preterm infants with ROP had lower indices of systemic oxygenation, as measured by median SpO2 and PCO2, and lower HbF levels up to 34 weeks PMA.

According to the researchers, the study's findings suggest that low levels of HbF correlated with poor oxygenation indices and increased the risk of developing ROP. They suggested that oxygen saturation goals to prevent ROP may need to incorporate the relative amount of HbF in preterm infants.

Dr. Kim Jiramongkolchai the study's lead author, added, “These findings suggest that HbF levels may play a role in retinopathy of prematurity development and can potentially inform how we manage these critically ill infants. Larger sample sizes and longer follow-up periods in future studies are needed to confirm these findings.”

Reference:

Jiramongkolchai K., Repka M., Tian J., Aucott S., Shepard J., Collins M., Clemens J., Feller M., Burd I., Roizenblatt M., Smith K., Arevalo JF., Gehlbach P., Handa J.; Effects of fetal haemoglobin on systemic oxygenation in preterm infants and the development of retinopathy of prematurity PacIFiHER Report No. 2; British Journal of Ophthalmology2023; 2023.03.20 doi: 10.1136/bjo-2023-323354