Prophylactic amnioinfusion in pregnancies complicated by thick meconium

We hypothesized that prophylactic intrapartum amnioinfusion in pregnancies complicated by thick meconium will not decrease the incidence of fetal distress, cesarean section for fetal distress, or meconium below the cords.

Patients with thick meconium were randomized to amnioinfusion (n = 65) or control (n = 59). The amnioinfusion group received an 800 ml bolus of normal saline solution followed by a continuous infusion at 180 ml/hr. Continuous variables were compared by Student t test, and discrete variables were compared by chi 2 analysis and Fisher's exact test as appropriate.

The incidence of fetal distress (16 of 65 vs 8 of 59) and cesarean section for fetal distress (seven of 65 vs seven of 59) was not significantly different between the amnioinfusion and control groups, respectively. The rate of meconium below the cords (one of 65 vs eight of 59) was significantly lower in patients receiving amnioinfusion (relative risk 0.09, confidence interval 0.01 and 0.82, p = 0.02). Two cases of meconium aspiration syndrome occurred in control patients but in none receiving amnioinfusion (p = 0.22).

Prophylactic amnioinfusion in patients with thick meconium decreases the incidence of meconium below the cords and may subsequently have an impact on the incidence of meconium aspiration syndrome in larger series.