Dose relationship between maternal milk proportion and necrotizing enterocolitis development

Abstract

Background: To examine the dose effect of maternal milk (MM) feeding on neonatal necrotizing enterocolitis (NEC) development. Methods: This retrospective study included 305 infants [birth weight<1 500 g, or gestation age (GA)<32 weeks]. Curve estimation was performed to evaluate the dose relationship between MM proportion and NEC. Then infants were grouped based on curve trend and multivariable regression analysis was conducted to prove the curve estimation.Results: Rate of NEC for the sample was 7.9% and age at onset was 25.6(16.0–26.0) days. The curve showed that when MM proportion was increased from zero to 20%, rate of NEC increased from 25% to 40% at first and when MM from 20% to 100%, rate dropped from 40% to near zero. In the MM proportion from zero to 40%, rate of NEC changed greatly. The multiple regression analysis showed that compared with MM proportion >0.70, 0.4<MM proportion £0.7 was associated with a 5.482- fold higher odds of developing NEC（P=0.032）; 0<MM proportion £0.4 was a 24.99-fold increase in the odds of developing NEC（P<0.001）; MM proportion =0 was a 9.348-fold increase in the odds of developing NEC（P=0.003）. Conclusion: This study estimated how rate of NEC changed with MM proportion increase, MM proportion being greater than 40% had a significant protection against NEC. We should encourage mother for breast milk and alert to NEC when the preterm is mixed feeding with MM proportion less than 40%.