Low Splanchnic Oxygenation and Risk for Necrotizing Enterocolitis in Extremely Preterm Newborns

The aim of the study was to investigate whether splanchnic oxygenation (SrSO2), measured with near-infrared spectroscopy (NIRS), during the first week of life is associated with the risk of developing necrotizing enterocolitis (NEC) in extremely preterm infants.

This was a prospective observational cohort study including extremely preterm infants (<28 weeks of gestation) born at Karolinska University Hospital from September 2014 to December 2016. Using 1-hour NIRS monitoring during enteral feeding, mainly continuous enteral feeding, in the first week of life we measured both cerebral and splanchnic oxygenation. Primary outcome was risk of developing NEC (Bell stage ≥ II). Secondary outcome was the association between low mean SrSO2 during the first week of life and postnatal age at full enteral nutrition.

We enrolled 52 extremely preterm newborns, but only 45 infants had complete NIRS data. One infant developed NEC within 1 day of NIRS monitoring and was excluded from the study. Median gestational age was 25.6 weeks (range 23.0-27.9) and median birth weight 698 g (range 485-1353). Eight infants developed NEC at the median postnatal age of 15 days (range 6-35). Median postnatal age at full enteral nutrition was 10 days (range 6-23). Infants with mean SrSO2 <30% had a higher risk for developing NEC compared with those with SrSO2 >30% (crude risk ratio 5.25; 95% CI [1.19-23.01]). Small for gestational age, gestational age, birth weight, postnatal age did not affect the results. We found no association between SrSO2 and age at full enteral nutrition.

Low mean SrSO2 (<30%) during the first week of life is associated with an increased risk for developing NEC in extremely preterm infants on mainly continuous enteral nutrition.