Randomised trial of amnioinfusion during labour with meconium stained amniotic fluid

Objective To assess the effect of amnioinfusion during labour with meconium stained amniotic fluid on caesarean section rate and perinatal outcome.

Design Prospective randomised controlled study.

Setting A tertiary care teaching hospital in India.

Population Women in labour at term with meconium stained amniotic fluid.

Methods Two hundred women in labour with ≥37 weeks gestation, single cephalic presentation with moderate or thick meconium were randomised to control and amnioinfusion groups at a 1:1 ratio. Amnioinfusion was performed using 500mL of normal saline over a period of 30 minutes in a study group. The control group received routine care. Both groups had intermittent auscultation of fetal heart rate during labour.

Main outcome measures The primary outcome measure was caesarean section rate. Secondary outcome measures were meconium aspiration syndrome, 1 minute and 5 minute apgar <7, hypoxic ischaemic encephalopathy, neonatal intensive care unit admission, meconium at the level of vocal cords.

Results The caesarean section rate in the amnioinfusion group was less than the control group (RR 0.47; 95% CI 0.24–0.93). Amnioinfusion was associated with a significant decrease in the incidence of meconium at the vocal cords (P= 0.001); improvement in 1 minute apgar scores (P <0.05), respiratory distress (P= 0.002) and fewer admissions to nursery compared with the controls. This sample size was inadequate to study the impact on meconium aspiration syndrome.

Conclusion Amnioinfusion in an under resourced labour ward decreases caesarean section rates and fetal morbidity.