Thirteen studies (2 of which were reported in abstract form) with 1,924 participants (950 who received amnioinfusion during labour and 974 controls) were included in the review .
Intrapartum amnioinfusion significantly reduced the frequency of meconium aspiration syndrome (OR 0.30, 95% CI: 0.19, 0.46).
Intrapartum amnioinfusion significantly reduced the presence of meconium below the vocal cords (OR 0.18, 95% CI: 0.11, 0.27).
Intrapartum amnioinfusion significantly reduced neonatal acidaemia (OR 0.42, 95% CI: 0.28, 0.62). Patients allocated to receive amnioinfusion also had a significantly lower overall Caesarean rate (OR 0.74, 95% CI: 0.59, 0.93) without increased postpartum endometritis (OR 0.47, 95% CI: 0.31, 0.72).
There were several reports of adverse events associated with amnioinfusion. It increased basal uterine tone even when a small volume (250 mL) of infusate was used. Uterine hypertonus and foetal bradycardia have been associated with specific infusion protocols, although they seem to be eliminated by adjustment of the infusion rate.
Statistically significant heterogeneity was found for the outcomes of frequency of meconium aspiration syndrome, presence of meconium below the vocal cords, and neonatal acidaemia.
The funnel plot analysis was not consistent with publication bias.