Amnioinfusion

Bibliographic reference Study type Evidence level Number of patients Patient characteristics Intervention Comparison Length of follow-up Outcome measures Effect size Source of funding Additional comments
Hofmeyr GJ; 2000470Systematic review - meta- analysisEvidence level: 1+12 RCTs involving
Intervention groups N=909
Control groups N=898 (NB. Numbers from 11 of the 12 studies)
Women in labour at term with meconium stained liquor.Intervention: Amnioinfusion for meconium- stained liquor during labour.Comparison: No amnioinfusion.Follow-up period: Not clear but includes neonatal hypoxis ischaemic encephalopathy - ? Few days PN.Outcome Measures: Heavy meconium staining of liquor, variable FH decelerations, Caesarean section, meconium aspiration syndrome, neonatal hypoxic ischaemic encephalopathy, neonatal ventilation, NICU admission, perinatal mortality.Under standard perinatal surveillance:
Reduced heavy meconium staining of liquor RR 0.03, CI 0.01 to 0.15
Reduced variable FH decelerations RR 0.65, CI 0.49 to 0.88
Reduced Caesarean section RR 0.82, CI 0.69 to 0.97
Under limited perinatal surveillance reduced:
Meconium aspiration syndrome RR 0.24, CI 0.12 to 0.48
Neonatal hypoxic ischaemic encephalopathy RR 0.07, CI 0.01 to .056
Neonatal ventilation or NICU admission RR 0.56, CI 0.39 to 0.79
Trend towards reduced perinatal mortality RR 0.34, CI 0.11 to 1.06.
Not stated
Fraser WD;Hofmeyr J;Lede R;Faron G;Alexander S;Goffinet F;Ohlsson A;Goulet C;Turcot- Lemay L;Prendiville W;Marcoux S;Laperriere L;Roy C;Petrou S;Xu HR; 2005 Sep 1471RCTEvidence level: 1+Intervention group N=995
Control group N=1003
Women in labour at term with MSLIntervention: AmnioinfusionComparison: No amnioinfusionFollow-up period: Not stated exactly - but appears to be within 24 hours of birth.Outcome Measures: Main composite outcome measures are perinatal death, moderate or severe meconium aspiration syndrome, or both.
Secondary outcomes included serious neonatal morbidity (list of included conditions given) or serious maternal complications.
Main composite outcome occurred in 44 infants in intervention group (4.5%) and 35 in control group (3.5%), RR 1.26, CI 0.82 to 1.95.
No signif. differences wrt moderate or severe MAS, perinatal deaths, mild respiratory distress.
Stratified analysis showed no signif. effect of amnioinfusion on the rate of primary outcome regardless of whether late decelerations were present or not (3.4% in infusion group vs. 3.2% in control group, RR 1.83, CI 0.84 to 3.99).
Also no signif. diff re fetal umbilical artery pH or abnormal CTG.
Supported by Canadian Institutes of Health Research, Utah Medical Products and Institut National de la Sante et de la Recherche Medicale.See previous page
Puertas A;Paz CM;Molto L;Alvarez M;Sedeno S;Miranda JA; 2001
472
RCTEvidence level: 1+Intervention N=103
Control N=103
Wmen in labour at term with meconium stained liquorIntervention: AmnioinfusionComparison: Amnioinfusion versus no amnioinfusionFollow-up period: A few days PN - PN stay.Outcome Measures:
Main outcome = caesarean section.
Maternal and neonatal morbidity.
Increased spontaneous birth RR 1.41, CI 1.1 to 1.8, p=0.004
Reduced Caesarean section RR 0.5, CI 0.26 to 1.1, p=0.043
Reduced CS for fetal distress RR 0.23, CI 0.07 to 0.79, p=0.019
Reduced variable decelerations RR 0.74, CI 0.59 to 0.92, p=0.009
Reduced late variable decelerations RR 0.37, CI 0.21 to 0.66, p<0.001
arterial pH <7.20 RR 0.58, CI 0.35 to 0.97, p=0.049
Meconium below cords RR 0.37, CI 0.19 to 0.69, p=0.001
Fondos de Investigacion Sanitaria.
Rathor AM;Singh R;Ramji S;Tripathi R; 2002 Jan 474Study Type: RCT.Evidence level: 1+Number of women: Amnioinfusion group n=100
Control group n=100.
Inclusion/exclusion : Women in labour at term with MSLAmnioinfusion of normal salineNo infusionFollow-up period: Immediate PN period.Outcome Measures: CS rate - overall and for fetal distress.
Secondary outcome measures: MAS, 1 and 5 minute Apgar scores < 7, hypoxic ischaemic encephalopathy, admission to NICU, meconium at level of vocal cords.
Amnioinfusion vs control
Overall CS: 21% vs 36% (RR0.47, 95% CI 0.24 to 0.93)
CS for fetal distress: 12% vs 26% (RR=0.39, 95% CI 0.17 to 0.87)
MAS: 0 vs 1
1 min Apgar < 7: 2/94 vs 8/98 (RR=0.24, 95% CI 0.03 to 1.29
5 minute Apgar scores < 7: 1/99 vs 2/96, NS
Admission to NICU: 3% vs 11% (RR=0.25, 95% CI 0.05 to 1.01
Meconium at level of vocal cords: 10% vs 24% (RR=0.35, 95% CI 0.15 to 0.83)
Maternal pyrexia: 6% vs 12% (RR=0.47, 95% CI 0.15 to 1.42).
Not statedAmnioinfusion in an under- resourced labour ward decreases CS rates and fetal morbidity.
Edwards RK;Duff P;

1999475
RCTEvidence level: 1+Antibiotic group n=93
Control group n=90
Women in labour at term with MSLIntervention: Amnioinfusion with antibiotic solution (cefazolin)Comparison: Amnioinfusion with salineFollow-up period: Few days PN (eg. to confirm neonatal infection)Outcome Measures: Clinical chorioamnionitis
Postpartum endometritis
Aggregate maternal infection
Suspected neonatal infection
Proven neonatal infection
Antibiotic vs saline amnioinfusion - no significant differences found.
Clinical chorioamnionitis: 7.8% vs 8.6%
Postpartum endometritis: 2.4% vs 3.5%
Aggregate maternal infection: 10.0% vs 11.8%
Suspected neonatal infection: 17.8% vs 21.5%
Proven neonatal infection: 0.0% vs 2.2%
Southern Medical AssociationUnderpower ed.
Gonzalez JL;Mooney S;Gardner MO;Martin D;Curet LB;

2002476
RCTEvidence level: 1+Intervention 1 = 20
Intervention 2 = 20
Control = 21
Women inlabour at term with MSLIntervention: Amnioinfusion with lactated Ringer's solutionComparison: Amnioinfusion with normal saline
or no amnioinfusion
Follow-up period: N/AOutcome Measures: Neonatal plasma electrolyte concentrations.Sodium, choride and potassium - NS
pH LR 7.30 +- 0.07
pH NS 7.26 +- 0.06
pH C 7.29 +- 0.08
p=0.11
Not statedStudy conducted in place where amnioinfusion already accepted as normal practice - benefits not questioned in this paper.
Glantz JC;Letteney DL; 1996 Jan477;478Study Type: Non-systematic review of 11 RCTs and 1 prospective cohort study.Evidence level: 1−Number of women: 543 in total.Inclusion/exclusion : Pregnant women in labourAmnioinfusion - with warmersor infusion pumpsFollow-up period: N/A.Outcome Measures: Type of birth
Fetal distress
Low 5 min Apgar score
Meconium below cords
Endometritis
Warm solution vs room temp: CS: OR=0.44 (95% CI 0.25 to 0.76) vs 0.89 (0.44 to 1.81), p=0.15
Fetal distress: OR=0.22 (95% CI 0.11 to 0.44) vs 0.61 (0.31 to 1.19), p=0.26
Low 5 min Apgar score: OR=0.39 (0.14 to 1.12) vs 1.06 (0.25 to 4.38), p=0.29
Mecomium below cords: OR= 0.06 (0.02 to 0.17) vs 0.20 (0.06 to 0.64), p=0.80
Endometritis: OR= 0.41 (0.16 to 1.09) vs 1.06 (0.32 to 3.51, p=0.23

Pump vs gravity infusion: CS: OR=0.81 (95% CI 0.40 to 1.66) vs 0.36 (0.21 to 0.62), p=0.18
Fetal distress: OR=0.58 (95% CI 0.27 to 1.23) vs 0.24 (0.13 to 0.45), p=0.35
Low 5 min Apgar score: OR=0.96 (0.16 to 5.70) vs 0.42 (0.16 to 1.14), p=0.49
Meconium below cords: OR= 0.20 (0.08 to 0.46) vs 0.90 (0.03 to 0.28), p=0.82
Endometritis: OR= 0.61 (0.19 to 1.90) vs 0.52 (0.20 to 1.33, p=0.88.
Not statedTo date there is no demonstrable benefit using infusion pumps or solution warmers. Poor quality evidence. Also, none of the studies investigated use of pumps or warmers as the prime focus of the research.

From: Evidence tables

Cover of Intrapartum Care
Intrapartum Care: Care of Healthy Women and Their Babies During Childbirth.
NICE Clinical Guidelines, No. 55.
National Collaborating Centre for Women's and Children's Health (UK).
London: RCOG Press; 2007 Sep.
Copyright © 2007, National Collaborating Centre for Women’s and Children’s Health.

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