Impact of meconium consistency on infant resuscitation and respiratory outcomes: a retrospective-cohort study and systematic review

OBJECTIVE: To compare short-term outcomes of infants born with thick versus thin meconium stained amniotic fluid (MSAF) and to perform a systematic review of the topic. METHODS: A retrospective, single center, cohort study of infants' ≥34 weeks' gestation born with MSAF between 1 June 2013 and 30 September 2016. Birth resuscitation and respiratory outcomes were compared between the groups. A systematic review was conducted of similar studies published between 1 January 2000 and 30 June 2019. RESULTS: 1507 infants were eligible; 464 (30.8%) thick, 1,043 (69.2%) thin MSAF. The thick group required more respiratory support at birth and was 5.5-fold (95% CI: 2.51-11.95) more likely to and have meconium aspiration syndrome (MAS) and 2.1-fold more likely (95% CI: 0.89-4.83) to require either noninvasive respiratory support or intubation than the thin group. The thick group also had significantly higher oxygen supplementation >24 h (p < .001) and pneumothorax (p = .002). Across 12 studies included in the systematic review, infants with thick MSAF required more intensive birth resuscitation, ventilation support, with higher incidences of MAS. Study differences prohibited data comparisons and quantitative outcome evaluations. CONCLUSION: Infants with thick MSAF required more intensive birth resuscitation and ventilation support. Our findings need confirmation in robust, prospective cohort studies.