Randomised trial of amnioinfusion during labour with meconium stained amniotic fluid

Abstract

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 > or = 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 500 mL 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.