AMNIOTIC-FLUID MECONIUM - A FETAL ENVIRONMENTAL-HAZARD

Objective: To investigate the hypothesis that meconium aspiration synd rome, the major hazard of meconium during labor, may be associated wit h superimposed fetal acute acidemia. Methods: Umbilical artery blood g ases were measured in 7816 term pregnancies with meconium in the amnio tic fluid (AF) and the results were correlated with intrapartum and ne onatal outcomes. Results: Sixty-nine (1%) infants developed meconium a spiration syndrome and 31 (45%) of these were in association with feta l acidemia at birth. Moreover, umbilical blood gas analysis and intrap artum events suggested that the fetal acidemia linked to meconium aspi ration was an acute event rather than a long-duration process, which m ight be expected if meconium was itself a marker of an antecedent feta l asphyxial event. Conclusion: Meconium in the AF may be a fetal envir onmental hazard when acidemia supervenes rather than solely a marker o f preexisting fetal compromise leading to the release of meconium.