"Meconiumcrit" and birth asphyxia.

Determination of the percent by volume of the solid component of meconium (the "meconiumcrit") provides a more objective method of characterizing the type of meconium. In a study of 106 women with meconium-stained amniotic fluid, 61 (58%) had thin meconium, 36 (34%) had moderate meconium, and nine (8%) had thick meconium. There was no correlation between the type of meconium and newborn acidemia (umbilical artery pH, less than 7.20)--13%, 19%, and 11%, respectively. None of the newborns with either thin or thick meconium had 1-minute Apgar scores of less than or equal to 3 and only two with moderate meconium had such Apgar scores; none had an Apgar score of less than or equal to 3 at 5 minutes. None of the newborns with thin or moderate meconium had meconium aspiration syndrome, although two of nine infants with thick meconium did have meconium aspiration syndrome. All newborns subsequently did well and left the hospital in good condition. There would appear to be no correlation between the consistency of meconium and recently reported criteria for defining birth asphyxia.