The effect of meconium thickness level on neonatal outcome

Background: Despite its prevalence and potential maternal and neonatal implications, the literature on the thickness levels of meconium stained amniotic fluid (MSAF) and its impact on neonatal outcomes is relatively outdated and relies on relatively small sample sizes. Aims: To study if different thickness levels of MSAF correlate with adverse neonatal outcome. Study design: A retrospective cohort study. Subjects: The medical records and neonatal charts of all women with a singleton pregnancy, who underwent a trial of labor, at 37 + 0/7 weeks or beyond, between 10/2008 and 7/2018 were reviewed. Outcome measures: The cohort was divided according to the level of meconium reported during labor into four groups: Clear (C group), Light meconium (LM group), Intermediate meconium (IM group), and Heavy meconium (HM group). Composite neonatal outcome included at least one of the following: umbilical artery pH ≤ 7.1, sepsis, need for blood transfusion, need for phototherapy, respiratory distress syndrome, meconium aspiration syndrome, need for mechanical ventilation support, necrotizing enterocolitis, intraventricular hemorrhage, hypoxic ischemic encephalopathy, periventricular leukomalacia, seizures, hypoglycemia, hypothermia, and death. Continuous parameters were compared with Anova's test or Kruskal Wallis, and categorical variables by chi-square test or Fisher exact test, as appropriate. Multivariant logistic regression was performed in order to eliminate possible cofounders. Results: Overall, 24,445 deliveries were reviewed (C-20,185, LM-1074, IM-2736, HM-450). Composite adverse neonatal outcome was more common with increasing thickness of MSAF. On multivariable analysis, IM and HM were independently associated with composite adverse neonatal outcome. Conclusion: The degree of meconium thickness independently correlates with composite adverse neonatal outcome.