Meconium: a 1990s perspective on an old obstetric hazard.

OBJECTIVE

To quantify the current perinatal consequences associated with intrapartum detection of meconium in the amniotic fluid (AF).

METHODS

We compared retrospectively the outcomes in 8136 term singleton cephalic pregnancies with meconium and 34,573 similar pregnancies with clear AF.

RESULTS

Virtually all measures of adverse fetal-neonatal outcomes were significantly increased with meconium. For example, perinatal mortality increased from 0.3 per 1000 births with clear AF to 1.5 deaths per 1000 with meconium (P < .001). Most of these deaths resulted from meconium aspiration. Other unwanted outcomes also increased; eg, severe fetal acidemia at birth (umbilical artery blood pH 7.00 or less) increased from three per 1000 to seven per 1000 when meconium was diagnosed (P < .001). Delivery by cesarean also increased with meconium, from 7 to 14% (P < .001).

CONCLUSION

Meconium in the AF is an obstetric hazard with small but significantly increased risks of adverse fetal-neonatal outcomes.