[Clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for severe MAS in neonates with meconium-stained amniotic fluid].

Objectives: To study the clinical features of severe meconium aspiration syndrome (MAS) and early predicting factors for the development of severe MAS in neonates with meconium-stained amniotic fluid (MSAF).

Methods: A total of 295 neonates who were hospitalized due to Ⅲ° MSAF from January 2018 to December 2019 were enrolled as subjects. The neonates were classified to a non-MAS group (=199), a mild/moderate MAS group (=77), and a severe MAS group (=19). A retrospective analysis was performed for general clinical data, blood gas parameters, infection indicators, and perinatal clinical data of the mother. The respiratory support regimens after birth were compared among the three groups. The receiver operating characteristic (ROC) curve and multivariate logistic regression analysis were used to investigate predicting factors for the development of severe MAS in neonates with MSAF.

Results: Among the 295 neonates with MSAF, 32.5% (96/295) experienced MAS, among whom 20% (19/96) had severe MAS. Compared with the mild/moderate MAS group and the non-MAS group, the severe MAS group had a significantly lower 5-minute Apgar score (<0.05) and a significantly higher blood lactate level in the umbilical artery (<0.05). Compared with the non-MAS group, the severe MAS group had a significantly higher level of interleukin-6 (IL-6) in peripheral blood at 1 hour after birth (<0.017). In the severe MAS group, 79% (15/19) of the neonates were born inactive, among whom 13 underwent meconium suctioning, and 100% of the neonates started to receive mechanical ventilation within 24 hours. Peripheral blood IL-6 >39.02 pg/mL and white blood cell count (WBC) >30.345×10/L at 1 hour after birth were early predicting indicators for severe MAS in neonates with MSAF (<0.05).

Conclusions: Meconium suctioning cannot completely prevent the onset of severe MAS in neonates with MSAF. The neonates with severe MAS may develop severe respiratory distress and require mechanical ventilation early after birth. Close monitoring of blood lactate in the umbilical artery and peripheral blood IL-6 and WBC at 1 hour after birth may help with early prediction of the development and severity of MAS.