It has been unclear whether amnioinfusion (i.e., transcervical infusion of saline into the amniotic cavity) in women with meconium-stained amniotic fluid during labor reduces risk for meconium aspiration syndrome. Results from one randomized trial suggested a beneficial effect, but routine fetal heart-rate monitoring and neonatal resuscitation were unavailable in that clinical setting (BJOG 1998; 105:309). In the current international, multicenter study, 1998 women who were in labor with full-term singleton gestations and had meconium-stained amniotic fluid were randomized to receive amnioinfusion or standard care; continuous electronic fetal heart-rate monitoring was performed in both groups. Baseline demographic and obstetric characteristics did not differ significantly between the groups.
Incidence of the primary endpoint — a composite of perinatal death, moderate or severe meconium aspiration syndrome, or both — did not differ significantly between the amnioinfusion and standard-care groups (4.5% and 3.5%, respectively). In particular, moderate or severe meconium aspiration syndrome (assessed according to clinical criteria) occurred in 43 and 31 infants, respectively, and there were five perinatal deaths in each group.
Comment: In this large trial, amnioinfusion did not reduce risk for meconium aspiration syndrome or perinatal death. Perhaps many, if not most, infants with meconium aspiration syndrome have meconium in their pulmonary tree prior to labor. The authors conclude that amnioinfusion should not be recommended for the prevention of meconium aspiration syndrome in settings where standard peripartum surveillance is available.
— Ann J. Davis, MD
Published in Journal Watch Women's Health October 18, 2005