Antenatal umbilical Doppler abnormalities: an independent risk factor for early onset neonatal necrotizing enterocolitis in premature infants

Background: Necrotizing enterocolitis (NEC) is the most common gastrointestinal (GI) emergency seen in neonatal units. Many factors have been considered as potentially important aetiologically, including gut ischaemia, sepsis and feeding. However, evidence remains equivocal. Objective: This study investigated whether preterm babies born to mothers with abnormal antenatal umbilical Dopplers (absent or reversed end diastolic flow - AREDF), that is exposed to antenatal gut ischaemia, are at an identical risk of developing NEC early in life, compared to babies born to mothers with normal Dopplers. Methods: All preterm (<= 32 + 6 week gestation) babies with no congenital anomaly, born to mothers resident in the county of Leicestershire in United Kingdom in 2001 and 2002 were identified using the Trent Neonatal Survey (TNS). Clinical data including the presence and severity of any NEC were extracted from the notes. Results: Two hundred forty-three preterm babies who met the criteria were identified during the period. Babies in whom umbilical Dopplers were not available and babies that died in the first 48 h were excluded. Complete data was thus available for 206 of these babies. A strong relation between AREDF and subsequent development of NEC was noted in these babies (OR: 5.88, 95% CI: 2.41 to 14.34, p < 0.0001). This association still held after adjustment for gestational age at birth (OR: 7.64, 95% CI: 2.96 to 19.70, p < 0.0001) and after adjustment for birthweight for gestational age z-score (OR: 6.72, 95% CI: 2.23 to 20.25, p = 0.0007).