460 - Cerebral Hypoxia is Associated with an Increased Risk of Severe Retinopathy of Prematurity in Extremely Preterm Infants

Publication Number: 3445.460

SHUYU LIN, Chang Gung Memorial Hospital, Taipei, Taiwan, Taipei city, Taipei, Taiwan (Republic of China); Kai-Hsiang Hsu, Chang Gung University and Chang Gung Memorial Hospital, Taoyuan, Taoyuan, Taiwan (Republic of China); Ming-Chou Chiang, Linkou Chang Gung Memorial Hospital, Gueishan District, Taoyuan, Taiwan (Republic of China); Wei-Hung Wu, Chang Gung Memorial Hospital, Linkou branch, Linkou, New Taipei, Taiwan (Republic of China); Reyin Lien, Chang Gung University, Gwei-Shan, Taoyuan, Taiwan (Republic of China)

Background: Retinopathy of prematurity (ROP) is a biphasic disease: initial vaso-obliteration after preterm birth, often related to hyperoxia and loss of maternal factors, followed by hypoxia-driven vaso-proliferation. Fluctuating oxygenation, especially intermittent hypoxia during the second phase, promotes abnormal retinal neovascularization and is a known risk factor in extremely preterm infants. Traditional prevention focused on strict oxygen control. Near-infrared spectroscopy (NIRS) measures regional cerebral oxygen saturation (rcSO₂) and has been proposed as a surrogate for retinal oxygenation given the close developmental link between brain and retina. Most prior NIRS studies examined the early postnatal period; few assessed longer-term cerebral oxygenation and ROP risk.

Objective: To examine the association between rcSO₂ during the first eight weeks of life and the development of severe ROP in extremely preterm infants.

Design/Methods: Post-hoc analysis of a prospective cohort including infants with a gestational age (GA) ≤28 weeks or birth weight (BW) ≤1000 g. Excluded were those who died before first ROP screening (≥28 days or PMA 31 weeks, whichever was later). RcSO₂ and arterial oxygen saturation (SaO₂) were recorded at 1-minute intervals using NIRS and pulse oximetry; fractional tissue oxygen extraction (FTOE) was calculated as (SaO₂ - rsSO₂)×100/SaO₂. Continuous monitoring covered the first 72 h from birth; then 1-h weekly sessions in the first month and monthly thereafter. Averaged rcSO₂, FTOE, and SaO₂ values at predefined timepoints (first 72 h, days 7, 14, 21, 28, 56) were analyzed. Generalized estimating equations (GEE) compared longitudinal trajectories between infants who developed severe ROP (stage ≥3 or requiring treatment) and those without.

Results: Twenty-eight infants (GA 27.2±1.94 weeks; BW 847±226 g) were included; 4 developed severe ROP. Those with severe ROP had lower GA and BW and were all male. Overall, rcSO₂ was not correlated with the corresponding PMA (r= -0.081, p=0.234) (Figure 1). After GA adjustment, GEE showed infants with severe ROP had consistently lower rcSO₂ and higher FTOE (group effect p=0.0495 and p< 0.0001, respectively). RcSO₂ declined and FTOE increased over time in both groups (time effect p< 0.05). SaO2 remained stable and similar between groups.

Conclusion(s): Persistent cerebral hypoxia (low rcSO2) and hypoperfusion (higher FTOE) are associated with severe ROP in extremely preterm infants, independent of systemic SaO2. Longitudinal NIRS monitoring may identify cerebral hypoxia/hypoperfusion beyond conventional pulse oximetry and help stratify risk for ROP.

Table 1. Baseline demographics and clinical characteristics


Table 2. Results of the multivariable GEE model with adjustment for gestational age


Figure 1. Correlation between PMA and rcSO2
Overall, rcSO₂ was not correlated with corresponding PMA (r= -0.081, p=0.234).
rcSO₂ , regional cerebral oxygen saturation; PMA, postmenstrual age.