Time to first passage of meconium and defecation frequency preceding necrotizing enterocolitis in preterm infants: a case–control study

Necrotizing enterocolitis (NEC) is associated with significant morbidity and mortality in preterm infants. Early recognition and treatment of NEC are critical to improving outcomes. Enteric nervous system (ENS) immaturity has been proposed as a key factor in NEC pathophysiology. Gastrointestinal dysmotility is associated with ENS immaturity and may serve as a predictive factor for the development of NEC. In this case–control study, preterm infants (gestational age (GA) < 30 weeks) were included in two level-IV neonatal intensive care units. Infants with NEC in the first month of life were 1:3 matched to controls based on GA (± 3 days). Odds ratios for NEC development were analyzed by logistic regression for time to first passage of meconium (TFPM), duration of meconial stool, and mean daily defecation frequency over the 72 h preceding clinical NEC onset (DF < T0). A total of 39 NEC cases and 117 matched controls (median GA 27 + 4 weeks) were included. Median TFPM was comparable in cases and controls (36 h [IQR 13–65] vs. 30 h [IQR 9–66], p = 0.83). In 21% of both cases and controls, TFPM was ≥ 72 h (p = 0.87). Duration of meconial stool and DF < T0 were comparable in the NEC and control group (median 4 and 3, resp. in both groups). Odds of NEC were not significantly associated with TFPM, duration of meconial stools, and DF < T0 (adjusted odds ratio [95% confidence interval]: 1.00 [0.99–1.03], 1.16 [0.86–1.55] and 0.97 [0.72–1.31], resp.). Conclusion: In this cohort, no association was found between TFPM, duration of meconium stool, and DF < T0 and the development of NEC. What is Known: • Necrotizing enterocolitis (NEC) is a life-threatening acute intestinal inflammatory disease of the young preterm infant. Early clinical risk factors for NEC have been investigated in order to facilitate early diagnosis and treatment. • Signs of disrupted gastrointestinal mobility, such as gastric retention and paralytic ileus, have been established to support the diagnosis of NEC. Nevertheless, defecation patterns have insufficiently been studied in relation to the disease. What is New: • Defecation patterns in the three days preceding NEC did not differ from gestational age-matched controls of corresponding postnatal age. Additionally, the first passage of meconium and the duration of meconium passage were comparable between cases and controls. Currently, defecation patterns are not useful as early warning signs for NEC. It remains to be elucidated whether these parameters are different based on the location of intestinal necrosis.