Birth weight Z-score and placental insufficiency as predictors of meconium-related ileus in preterm infants

Objective: Recent developments in neonatal care have led to increased survival rates of very-low-birth-weight infants; however, intestinal perforation remains associated with a poor prognosis. Meconium-related ileus (MRI) is more likely to develop in preterm infants and may lead to intestinal perforation. We aimed to investigate the perinatal risk factors for MRI in preterm infants. Study Design: This retrospective cohort study included 280 infants born between 22 and 31 weeks of gestation (23 and 257 in the MRI and non-MRI group, respectively). Comparisons of characteristics and fetal ultrasound findings between infants with and without MRI were conducted. Results: In the MRI group, the incidences of hypertensive disorders of pregnancy and non-reassuring fetal status were significantly higher (P < 0.001, for both), whereas the Z-scores for weight, height, and head circumference at birth, placental weight, umbilical artery pulsatility index, placental area, and cerebroplacental ratio (CPR) were significantly lower (P < 0.001, P < 0.001, P = 0.003, P = 0.020, P = 0.003, P = 0.041, and P = 0.001, respectively). After adjustment, the birth-weight Z-score remained an independent risk factor for MRI (odds ratio: 0.57, 95% confidence interval [CI]: 0.392–0.834; P = 0.004). Moreover, the birth weight Z-score (area under the curve: 0.77, 95% CI: 0.66–0.88) and CPR (area under the curve: 0.78, 95% CI: 0.62–0.94) were shown to be reliable predictors of MRI. Conclusion: A low birth-weight Z-score and low CPR may indicate that the pathogenesis of MRI involves poor intestinal motility due to placental insufficiency and fetal hypoxemia. Infants with a low birth-weight Z-score and placental insufficiency may serve from early and aggressive treatment with glycerin and gastrografin enemas.