Amnioinfusion for meconium-stained liquor in labour

  • Review
  • Intervention

Authors

  • GJ Hofmeyr


Prof G Justus Hofmeyr, Director/Hon. Professor, Effective Care Research Unit, Department of Obstetrics and Gynaecology, East London Hospital Complex, University of the Witwatersrand, University of Fort Hare, Eastern Cape Department of Health, Frere and Cecilia Makiwane Hospitals, Private Bag X 9047, East London, Eastern Cape, 5200, SOUTH AFRICA. gjh@global.co.za.

Abstract

Background

Amnioinfusion aims to prevent or relieve umbilical cord compression during labour by infusing a solution into the uterine cavity. It is also thought to dilute meconium when present in the amniotic fluid and so reduce the risk of meconium aspiration. However, it may be that the mechanism of effect is that it corrects oligohydramnios (reduced amniotic fluid), for which thick meconium staining is a marker.

Objectives

The objective of this review was to assess the effects of amnioinfusion for meconium-stained liquor on perinatal outcome.

Search strategy

The Cochrane Pregnancy and Childbirth Group trials register (October 2001) and the Cochrane Controlled Trials Register (Issue 3, 2001) were searched.

Selection criteria

Randomised trials comparing amnioinfusion with no amnioinfusion for women in labour with moderate or thick meconium-staining of the amniotic fluid.

Data collection and analysis

Eligibility and trial quality were assessed by one reviewer.

Main results

Twelve studies, most involving small numbers of participants, were included. Under standard perinatal surveillance, amnioinfusion was associated with a reduction in the following: heavy meconium staining of the liquor (relative risk 0.03, 95% confidence interval 0.01 to 0.15); variable fetal heart rate deceleration (relative risk 0.65, 95% confidence interval 0.49 to 0.88); and reduced caesarean section overall (relative risk 0.82, 95% confidence interval 0.69 to 1.97). No perinatal deaths were reported. Under limited perinatal surveillance, amnioinfusion was associated with a reduction in the following: meconium aspiration syndrome (relative risk 0.24, 95% confidence interval 0.12 to 0.48); neonatal hypoxic ischaemic encephalopathy (relative risk 0.07, 95% confidence interval 0.01 to 0.56) and neonatal ventilation or intensive care unit admission (relative risk 0.56, 95% confidence interval 0.39 to 0.79); there was a trend towards reduced perinatal mortality (relative risk 0.34, 95% confidence interval 0.11 to 1.06).

Authors' conclusions

Amnioinfusion is associated with improvements in perinatal outcome, particularly in settings where facilities for perinatal surveillance are limited. The trials reviewed are too small to address the possibility of rare but serious maternal adverse effects of amnioinfusion.

Plain language summary

Plain language summary

Amnioinfusion is beneficial for babies releasing medium to heavy meconium during labour, although further research into the effects on women is needed

A bowel movement (meconium) from the unborn baby during labour can enter the baby's lungs, causing breathing difficulties after birth. Extra liquid can be injected through the woman's vagina or abdomen into the womb (amnioinfusion) to provide more liquid to dilute the meconium and surround the baby. The review of trials found that amnioinfusion with a salt (saline) solution is beneficial for babies releasing medium to heavy meconium during their mother's labour. They are less likely to breathe in meconium or need breathing assistance after birth, and have better heart rates. Further research into the effects on women is needed.

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