Effect of infrared belt and hot water bag on labor pain intensity among primiparous: a randomized controlled trial

BACKGROUND

Labor pain is complex, paradoxical and varied in every parturient woman. Management of labor pain has been a crucial component in maternity care. Heat therapy is one of the proposed method for labor pain relief. Infrared is one of the methods of heat therapy but there is any study in this regard. This study aimed to compare the effect of the infrared belt and hot water bag on the severity of pain in the first stage of labor among primiparous women.

METHODS

In this clinical trial in the first stage of labor, 20-min cycles of heat therapy were conducted at the dilations of 4-5 and 6-7 cm in the intervention group 1 by an infrared belt and in the intervention group 2 by hot water bag, respectively. The control group received routine care. The severity of the pain was measured by the short-form McGill Pain Questionnaire.

RESULTS

In total, 136 women consented to participate in this clinical trial study. The mean score of pain intensity was significantly lower in the two intervention groups compared to the control group (P < 0.001). The mean pain intensity was significantly lower in the infrared belt group than in the hot water bag group (P < 0.001).

CONCLUSIONS

Based on these findings, heat therapy with an infrared belt reduced the severity of pain in the first stage of labor. The infrared belt could be used and recommended as a safe and effective pain relief in childbirth and maternity care.

TRIAL REGISTRATION

This study was registered in the Iran Clinical Trial Center with the code of IRCT20190805044446N1 .

Hypnosis for pain management during labour and childbirth

BACKGROUND

This review is one in a series of Cochrane Reviews investigating pain management for childbirth. These reviews all contribute to an overview of systematic reviews of pain management for women in labour, and share a generic protocol. We examined the current evidence regarding the use of hypnosis for pain management during labour and childbirth. This review updates the findings regarding hypnosis from an earlier review of complementary and alternative therapies for pain management in labour into a stand-alone review.

OBJECTIVES

To examine the effectiveness and safety of hypnosis for pain management during labour and childbirth.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (11 January 2012) and the reference lists of primary studies and review articles.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised controlled trials comparing preparation for labour using hypnosis and/or use of hypnosis during labour, with or without concurrent use of pharmacological or non-pharmacological pain relief methods versus placebo, no treatment or any analgesic drug or technique.

DATA COLLECTION AND ANALYSIS

Two assessors independently extracted data and assessed trial quality. Where possible we contacted study authors seeking additional information about data and methodology.

MAIN RESULTS

We included seven trials randomising a total of 1213 women. All but one of the trials were at moderate to high risk of bias. Although six of the seven trials assessed antenatal hypnotherapy, there were considerable differences between these trials in timing and technique. One trial provided hypnotherapy during labour. No significant differences between women in the hypnosis group and those in the control group were found for the primary outcomes: use of pharmacological pain relief (average risk ratio (RR) 0.63, 95% confidence interval (CI) 0.39 to 1.01, six studies, 1032 women), spontaneous vaginal birth (average RR 1.35, 95% CI 0.93 to 1.96, four studies, 472 women) or satisfaction with pain relief (RR 1.06, 95% CI 0.94 to 1.20, one study, 264 women). There was significant statistical heterogeneity in the data for use of pharmacological pain relief and spontaneous vaginal birth. The primary outcome of sense of coping with labour was reported in two studies as showing no beneficial effect (no usable data available for this review).  For secondary outcomes, no significant differences were identified between women in the hypnosis group and women in the control group for most outcomes where data were available. For example, there was no significant difference for satisfaction with the childbirth experience (average RR 1.36, 95% CI 0.52 to 3.59, two studies, 370 women), admissions to the neonatal intensive care unit (average RR 0.58, 95% CI 0.12 to 2.89, two studies, 347 women) or breastfeeding at discharge from hospital (RR 1.00, 95% CI 0.97 to 1.03, one study, 304 women). There was some evidence of benefits for women in the hypnosis group compared with the control group for pain intensity, length of labour and maternal hospital stay, although these findings were based on single studies with small numbers of women. Pain intensity was found to be lower for women in the hypnosis group than those in the control group in one trial of 60 women (mean difference (MD) -0.70, 95% CI -1.03 to -0.37). The same study found that the average length of labour from 5 cm dilation to birth (minutes) was significantly shorter for women in the hypnosis group (mean difference -165.20, 95% CI -223.53 to -106.87, one study, 60 women). Another study found that a smaller proportion of women in the hypnosis group stayed in hospital for more than two days after the birth compared with women in the control group (RR 0.11, 95% CI 0.02 to 0.83, one study, 42 women).

AUTHORS' CONCLUSIONS

There are still only a small number of studies assessing the use of hypnosis for labour and childbirth. Although the intervention shows some promise, further research is needed before recommendations can be made regarding its clinical usefulness for pain management in maternity care.

Non-opioid drugs for pain management in labour

BACKGROUND

Labour is a normal physiological process, but is usually associated with pain and discomfort. Numerous methods are used to relieve labour pain. These include pharmacological (e.g. epidural, opioids, inhaled analgesia) and non-pharmacological (e.g. hypnosis, acupuncture) methods of pain management. Non-opioid drugs are a pharmacological method used to control mild to moderate pain.

OBJECTIVES

To summarise the evidence regarding the effects and safety of the use of non-opioid drugs to relieve pain in labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (15 February 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) using non-opioid drugs (non-steroidal anti-inflammatory drugs (NSAIDs); paracetamol; antispasmodics; sedatives and antihistamines) in comparison with placebo or standard care; different forms of non-opioid drugs (e.g. sedatives versus antihistamines); or different interventions (e.g. non-opioids versus opioids) for women in labour. Quasi-RCTs and trials using a cross-over design were not included. Cluster-randomised RCTs were eligible for inclusion but none were identified for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed for inclusion all studies identified by the search strategy, carried out data extraction and assessed risk of bias. We resolved any disagreement through discussion with a third author. Data were checked for accuracy.

MAIN RESULTS

Nineteen studies randomising a total of 2863 women were included in this review. There were three main comparison groups: 15 studies compared non-opioid drugs with placebo or no treatment (2133 women); three studies compared non-opioid drugs with opioids (563 women); and three studies compared one type of non-opioid drug with a different type or dose of non-opioid drug (590 women). Some of the studies included three or more groups and so have been put in more than one comparison. Overall, there was little difference between groups for most of the comparisons. Any differences observed for outcomes were mainly limited to one or two studies. Non-opioid drugs (sedatives) were found to offer better pain relief (mean difference (MD) -22.00; 95% confidence interval (CI) -35.86 to -8.14, one trial, 50 women), better satisfaction with pain relief (sedatives and antihistamines) (risk ratio (RR) 1.59; 95% CI 1.15 to 2.21, two trials, 204 women; RR 1.80; 95% CI 1.16 to 2.79, one trial, 223 women) and better satisfaction with the childbirth experience (RR 2.16; 95% CI 1.34 to 3.47, one trial, 40 women) when compared with placebo or no treatment. However, women having non-opioid drugs (NSAIDs or antihistamines) were less likely to be satisfied with pain relief compared with women having opioids (RR 0.50; 95% CI 0.27 to 0.94, one trial, 76 women; RR 0.73; 95% CI 0.54 to 0.98, one trial, 223 women). Women receiving the antihistamine hydroxyzine were more likely to express satisfaction with pain relief compared with the antihistamine promethazine (RR 1.21; 95% CI 1.02 to 1.43, one trial, 289 women). Women receiving sedatives were more likely to express satisfaction with pain relief compared with antihistamines (RR 1.52; 95% CI 1.06 to 2.17, one study, 157 women). The majority of studies were conducted over 30 years ago. The studies were at unclear risk of bias for most of the quality domains.Opioids appear to be superior to non-opioids in satisfaction with pain relief, while non-opioids appear to be superior to placebo for pain relief and satisfaction with the childbirth experience. There were little data and no evidence of a significant difference for any of the comparisons of non-opioids for safety outcomes. 

AUTHORS' CONCLUSIONS

Overall, the findings of this review demonstrated insufficient evidence to support a role for non-opioid drugs on their own to manage pain during labour.

Local anaesthetic nerve block for pain management in labour

BACKGROUND

Local anaesthetic nerve block is an important modality for pain management in labour. Pudendal and paracervical block (PCB) are most commonly performed local anaesthetic nerve blocks which have been used for decades.

OBJECTIVES

To establish the efficacy and safety of local anaesthetic nerve blocks for pain relief in labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2012).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing pain management in labour with the use of local anaesthetic nerve blocks. We did not include results from quasi-RCTs.

DATA COLLECTION AND ANALYSIS

We designed a form to extract data. For eligible studies, two review authors extracted the data using the agreed form. We resolved discrepancies through discussion or, if required, we consulted a third person. We entered and analysed data using Review Manager software and checked for accuracy.

MAIN RESULTS

We found 41 trials for consideration of inclusion into this review. We included only 12 RCTs (1549 participants) of unclear quality. We excluded 29 studies (30 reports). The majority of excluded studies were not relevant to this review, and a few were not randomised.Local anaesthetic nerve block versus placebo or no treatment. We found that more women were satisfied with pain relief after local anaesthetic nerve block (in particular 2% lidocaine PCB) than after placebo (one study, 198 participants, risk ratio (RR) 32.31, 95% confidence interval (CI) 10.60 to 98.54). Local anaesthetic nerve block was associated with more side effects (one study, 200 participants, RR 29.0, 95% CI 1.75 to 479.61).Local anaesthetic nerve block (in particular, PCB) versus opioid Local anaesthetic nerve block (in particular, PCB) in comparison with opioid (in particular, intramuscular pethidine or fentanyl patient-controlled analgesia) was found to be more effective for pain relief (one study, 109 participants, RR 2.52, 95% CI 1.65 to 3.83) and was not associated with an increased rate of assisted vaginal birth (two studies, 129 participants, RR 1.02, 95% CI 0.56 to 1.87) or with an increased caesarean section rate (two studies, 129 participants, RR 0.23, 95% CI 0.03 to 1.87).Local anaesthetic nerve block versus non-opioid agents Satisfaction with pain relief and rate of caesarean sections were found to be the same in women receiving local anaesthetic nerve block and non-opioid agents (one study, 100 participants, RR 1.11, 95% CI 0.67 to 1.84; RR 2.0, 95% CI 0.19 to 21.36, respectively). More women who received non-opioid agent in comparison with women who received local anaesthetic nerve block required additional interventions for pain relief (one study, 100 participants, RR 0.06, 95% CI 0.02 to 0.25).Local anaesthetic nerve block using different anaesthetic agents There was no difference in pain relief satisfaction, assisted vaginal birth, caesarean section, side effects for mother, Apgar score or admission to the neonatal intensive care unit between different anaesthetic agents, e.g. bupivacaine, carbocaine, lidocaine, chloroprocaine.

AUTHORS' CONCLUSIONS

Local anaesthetic nerve blocks are more effective than placebo, opioid and non-opioid analgesia for pain management in labour based on RCTs of unclear quality and limited numbers. Side effects are more common after local anaesthetic nerve blocks in comparison with placebo. Different local anaesthetic agents used for pain relief provide similar satisfaction with pain relief. Further high-quality studies are needed to confirm the findings, to assess other outcomes and to compare local anaesthetic nerve blocks with various modalities for pain relief in labour.

Massage, reflexology and other manual methods for pain management in labour

BACKGROUND

Many women would like to avoid pharmacological or invasive methods of pain management in labour, and this may contribute towards the popularity of complementary methods of pain management. This review examined currently available evidence supporting the use of manual healing methods including massage and reflexology for pain management in labour.

OBJECTIVES

To examine the effects of manual healing methods including massage and reflexology for pain management in labour on maternal and perinatal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2 of 4), MEDLINE (1966 to 30 June 2011), CINAHL (1980 to 30 June 2011), the Australian and New Zealand Clinical Trial Registry (30 June 2011), Chinese Clinical Trial Register (30 June 2011), Current Controlled Trials (30 June 2011), ClinicalTrials.gov, (30 June 2011) ISRCTN Register (30 June 2011), National Centre for Complementary and Alternative Medicine (NCCAM) (30 June 2011) and the WHO International Clinical Trials Registry Platform (30 June 2011).

SELECTION CRITERIA

Randomised controlled trials comparing manual healing methods with standard care, no treatment, other non-pharmacological forms of pain management in labour or placebo.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We attempted to contact study authors for additional information.

MAIN RESULTS

We included six trials, with data reporting on five trials and 326 women in the meta-analysis. We found trials for massage only. Less pain during labour was reported from massage compared with usual care during the first stage of labour (standardised mean difference (SMD) -0.82, 95% confidence interval (CI) -1.17 to -0.47), four trials, 225 women), and labour pain was reduced in one trial of massage compared with music (risk ratio (RR) 0.40, 95% CI 0.18 to 0.89, 101 women). One trial of massage compared with usual care found reduced anxiety during the first stage of labour (MD -16.27, 95% CI -27.03 to -5.51, 60 women). No trial was assessed as being at a low risk of bias for all quality domains.

AUTHORS' CONCLUSIONS

Massage may have a role in reducing pain, and improving women's emotional experience of labour. However, there is a need for further research.

Intracutaneous or subcutaneous sterile water injection compared with blinded controls for pain management in labour

BACKGROUND

Intracutaneous or subcutaneous injection of sterile water is rapidly gaining popularity as a method of pain relief in labour and it is therefore essential that it is properly evaluated. Adequate analgesia in labour is important to women worldwide. Sterile water injection is inexpensive, requires basic equipment, and appears to have few side effects. It is purported to work for labour pain.

OBJECTIVES

To determine the efficacy of sterile water injections for relief of pain (both typical contraction pain and intractable back pain) during labour compared to placebo (isotonic saline injections) or non-pharmacological interventions, and to identify any relevant effects on mode and timing of delivery, or safety of both mother and baby.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 May 2011), MEDLINE, and EMBASE (January 2010 to 30 May 2011), together with reference lists in retrieved studies and review articles.

SELECTION CRITERIA

We included randomised, double blind, controlled studies using intracutaneous or subcutaneous sterile water injections for pain relief during labour. There were no restrictions on birth place, parity, risk, age, weight, gestation, or stage of labour. Potential comparators were placebo (saline) and non-pharmacological interventions (e.g. hypnosis or biofeedback).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and quality of trials, and extracted data. We resolved any disagreements or uncertainties by discussion with a third review author. Primary outcome measures were at least 50% pain relief, or at least 30%, pain relief, patient global impression of change of at least 'good', mode of delivery, perinatal morbidity and mortality, maternal complications and adverse events. Secondary outcomes were women with any pain relief, use of rescue analgesia, and treatment group average pain relief. We made explicit judgements about potential biases in the studies.

MAIN RESULTS

We included seven studies, with 766 participants: four used intracutaneous injections, two subcutaneous, and one both. All reported on low back pain in labour only. Methodological quality was good, but four studies were at high risk of bias due to small size of treatment groups, incomplete outcome data, and performance bias.All studies reported treatment group mean or median scores, finding greater reduction in pain for sterile water. However, failure to demonstrate a normal distribution for pain intensity or relief, and use of different scales, meant meta-analysis was inappropriate. No study reported primary dichotomous efficacy outcomes. One reported the number self-scoring 4/10 cm or more reduction in pain; significantly more had this outcome with sterile water (50% to 60%) than with placebo (20% to 25%).There was no significant difference between sterile water and saline for rates of caesarean section (risk ratio (RR) 0.58, 95% confidence interval (CI) 0.33 to 1.02), instrumental delivery (RR 1.31, 95% CI 0.79 to 2.18), rescue analgesia (RR 0.86, 95% CI 0.44 to 1.69), timing of delivery, or Apgar scores. Two studies reported that more women treated with sterile water would request the same analgesia in future.No study reported on women's satisfaction with pain relief, women's sense of control in labour, women's satisfaction with the childbirth experience, mother/baby interaction, rates of breastfeeding, maternal morbidity, infant long-term outcomes, or cost. No adverse events were reported other than transient pain with injection, which was worse with sterile water.

AUTHORS' CONCLUSIONS

The outcomes reported severely limit conclusions for clinical practice. We found little robust evidence that sterile water is effective for low back or any other labour pain. Neither did we find any difference in delivery or other maternal or fetal outcomes. Further large, methodologically rigorous studies are required to determine the efficacy of sterile water to relieve pain in labour.

Relaxation techniques for pain management in labour

BACKGROUND

Many women would like to avoid pharmacological or invasive methods of pain management in labour and this may contribute towards the popularity of complementary methods of pain management. This review examined currently available evidence supporting the use of relaxation therapies for pain management in labour.

OBJECTIVES

To examine the effects of relaxation methods for pain management in labour on maternal and perinatal morbidity.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 November 2010), The Cochrane Complementary Medicine Field's Trials Register (November 2011), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 4), MEDLINE (1966 to 30 November 2010), CINAHL (1980 to 30 November 2010), the Australian and New Zealand Clinical Trial Registry (30 November 2010), Chinese Clinical Trial Register (30 November 2010), Current Controlled Trials (30 November 2010), ClinicalTrials.gov, (30 November 2010) ISRCTN Register (30 November 2010), National Centre for Complementary and Alternative Medicine (NCCAM) (30 November 2010) and the WHO International Clinical Trials Registry Platform (30 November 2010).

SELECTION CRITERIA

Randomised controlled trials comparing relaxation methods with standard care, no treatment, other non-pharmacological forms of pain management in labour or placebo.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trials for inclusion and extracted data. Data were checked for accuracy. Two review authors independently assessed trial quality. We attempted to contact study authors for additional information.

MAIN RESULTS

We included 11 studies (1374 women) in the review. Relaxation was associated with a reduction in pain intensity during the latent phase (mean difference (MD) -1.25, 95% confidence interval (CI) -1.97 to -0.53, one trial, 40 women) and active phase of labour (MD -2.48, 95% CI -3.13 to 0.83, two trials, 74 women). There was evidence of improved outcomes from relaxation instruction with increased satisfaction with pain relief (risk ratio (RR) 8.00, 95% CI 1.10 to 58.19, one trial, 40 women) and lower assisted vaginal delivery (RR 0.07, 95% CI 0.01 to 0.50, two trials, 86 women). Yoga was associated with reduced pain (mean difference (MD) -6.12, 95% CI -11.77 to -0.47), one trial, 66 women), increased satisfaction with pain relief (MD 7.88, 95% CI 1.51 to 14.25, one trial, 66 women), satisfaction with the childbirth experience (MD) 6.34, 95% CI 0.26 to 12.42, one trial, 66 women), and reduced length of labour when compared to usual care (MD -139.91, 95% CI -252.50 to -27.32, one trial, 66 women) and when compared with supine position (MD -191.34, 95% CI -243.72 to -138.96, one trial, 83 women). Trials evaluating music and audio analgesia found no difference between groups in the primary outcomes pain intensity, satisfaction with pain relief, and caesarean delivery. The risk of bias was unclear for the majority of trials.

AUTHORS' CONCLUSIONS

Relaxation and yoga may have a role with reducing pain, increasing satisfaction with pain relief and reducing the rate of assisted vaginal delivery. There was insufficient evidence for the role of music and audio-analgesia. However, there is a need for further research.

Epidural versus non-epidural or no analgesia in labour

BACKGROUND

Epidural analgesia is a central nerve block technique achieved by injection of a local anaesthetic close to the nerves that transmit pain and is widely used as a form of pain relief in labour. However, there are concerns regarding unintended adverse effects on the mother and infant.

OBJECTIVES

To assess the effects of all modalities of epidural analgesia (including combined-spinal-epidural) on the mother and the baby, when compared with non-epidural or no pain relief during labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2011).

SELECTION CRITERIA

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

DATA COLLECTION AND ANALYSIS

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. We entered data into RevMan and double checked it for accuracy. Primary analysis was by intention to treat; we conducted subgroup and sensitivity analyses where substantial heterogeneity was evident.

MAIN RESULTS

We included 38 studies involving 9658 women; all but five studies compared epidural analgesia with opiates. Epidural analgesia was found to offer better pain relief (mean difference (MD) -3.36, 95% confidence interval (CI) -5.41 to -1.31, three trials, 1166 women); a reduction in the need for additional pain relief (risk ratio (RR) 0.05, 95% CI 0.02 to 0.17, 15 trials, 6019 women); a reduced risk of acidosis (RR 0.80, 95% CI 0.68 to 0.94, seven trials, 3643 women); and a reduced risk of naloxone administration (RR 0.15, 95% CI 0.10 to 0.23, 10 trials, 2645 women). However, epidural analgesia was associated with an increased risk of assisted vaginal birth (RR 1.42, 95% CI 1.28 to 1.57, 23 trials, 7935 women), maternal hypotension (RR 18.23, 95% CI 5.09 to 65.35, eight trials, 2789 women), motor-blockade (RR 31.67, 95% CI 4.33 to 231.51, three trials, 322 women), maternal fever (RR 3.34, 95% CI 2.63 to 4.23, six trials, 2741 women), urinary retention (RR 17.05, 95% CI 4.82 to 60.39, three trials, 283 women), longer second stage of labour (MD 13.66 minutes, 95% CI 6.67 to 20.66, 13 trials, 4233 women), oxytocin administration (RR 1.19, 95% CI 1.03 to 1.39, 13 trials, 5815 women) and an increased risk of caesarean section for fetal distress (RR 1.43, 95% CI 1.03 to 1.97, 11 trials, 4816 women). There was no evidence of a significant difference in the risk of caesarean section overall (RR 1.10, 95% CI 0.97 to 1.25, 27 trials, 8417 women), long-term backache (RR 0.96, 95% CI 0.86 to 1.07, three trials, 1806 women), Apgar score less than seven at five minutes (RR 0.80, 95% CI 0.54 to 1.20, 18 trials, 6898 women), and maternal satisfaction with pain relief (RR 1.31, 95% CI 0.84 to 2.05, seven trials, 2929 women). We found substantial heterogeneity for the following outcomes: pain relief; maternal satisfaction; need for additional means of pain relief; length of second stage of labour; and oxytocin augmentation. This could not be explained by subgroup or sensitivity analyses, where data allowed analysis. No studies reported on rare but potentially serious adverse effects of epidural analgesia.

AUTHORS' CONCLUSIONS

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.

Parenteral opioids for maternal pain relief in labour

BACKGROUND

Parenteral opioids are used for pain relief in labour in many countries throughout the world.

OBJECTIVES

To assess the acceptability, effectiveness and safety of different types, doses and modes of administration of parenteral opioids given to women in labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2010) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the use of intramuscular or intravenous opioids (including patient controlled analgesia) for women in labour. We looked at studies comparing an opioid with placebo or another opioid.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility, collected data and assessed risk of bias.

MAIN RESULTS

We included 54 studies involving more than 7000 women that compared an opioid with placebo or another opioid administered intramuscularly or intravenously. The 54 studies reported on 27 different comparisons, and for many outcomes only one study contributed data. Overall the evidence was of poor quality regarding the analgesic effect of opioids, satisfaction with analgesia, adverse effects and harm to women and babies. There were few statistically significant results. Many of the studies had small sample sizes, and low statistical power. Overall, findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour, although up to two-thirds of women who received opioids reported moderate or severe pain and/or poor or moderate pain relief one or two hours after administration. Opioid drugs were associated with maternal nausea, vomiting and drowsiness, although different opioid drugs were associated with different adverse effects. There was no clear evidence of adverse effects of opioids on the newborn. We did not have sufficient evidence to assess which opioid drug provided the best pain relief with the least adverse effects.

AUTHORS' CONCLUSIONS

Parenteral opioids provide some relief from pain in labour but are associated with adverse effects. Maternal satisfaction with opioid analgesia was largely unreported but appeared moderate at best. We did not examine the effectiveness and safety of parenteral opioids compared with other methods of pain relief in labour and this review needs to be examined alongside related Cochrane reviews. More research is needed to determine which analgesic intervention is most effective, and provides greatest satisfaction to women with acceptable adverse events for mothers and their newborns.

Transcutaneous electrical nerve stimulation (TENS) for pain relief in labour

BACKGROUND

Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. The TENS unit is frequently operated by women, which may increase sense of control in labour.

OBJECTIVES

To assess the effects of TENS on pain in labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008).

SELECTION CRITERIA

Randomised controlled trials comparing women receiving TENS for pain relief in labour versus routine care, alternative pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines.

DATA COLLECTION AND ANALYSIS

Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies.

MAIN RESULTS

The search identified 25 studies; we excluded six and included 19 studies including 1671 women. Fifteen examined TENS applied to the back, two to acupuncture points and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (risk ratio 0.41, 95% confidence interval 0.32 to 0.55). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No adverse events were reported.

AUTHORS' CONCLUSIONS

There is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact (either positive or negative) on other outcomes for mothers or babies. The use of TENS at home in early labour has not been evaluated. TENS is widely available in hospital settings and women should have the choice of using it in labour.

Immersion in water in labour and birth

BACKGROUND

Enthusiasts suggest that labouring in water and waterbirth increase maternal relaxation, reduce analgesia requirements and promote a midwifery model of care. Sceptics cite the possibility of neonatal water inhalation and maternal/neonatal infection.

OBJECTIVES

To assess the evidence from randomised controlled trials about immersion in water during labour and waterbirth on maternal, fetal, neonatal and caregiver outcomes.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (October 2008).

SELECTION CRITERIA

Randomised controlled trials comparing any bath tub/pool with no immersion during labour and/or birth.

DATA COLLECTION AND ANALYSIS

We assessed trial eligibility and quality and extracted data independently. One review author entered data and another checked for accuracy.

MAIN RESULTS

This review includes 11 trials (3146 women); eight related to the first stage of labour, one to the first and second stages, one to early versus late immersion in the first stage of labour, and another to the second stage. We identified no trials evaluating different baths/pools, or the management of third stage of labour.Results for the first stage of labour showed there was a significant reduction in the epidural/spinal/paracervical analgesia/anaesthesia rate amongst women allocated to water immersion compared to controls (478/1254 versus 529/1245; odds ratio (OR) 0.82, 95% confidence interval (CI) 0.70 to 0.98, six trials). There was no difference in assisted vaginal deliveries (OR 0.84, 95% CI 0.66 to 1.06, seven trials), caesarean sections (OR 1.23, 95% CI 0.86 to 1.75, eight trials), perineal trauma or maternal infection. There were no differences for Apgar score less than seven at five minutes (OR 1.59, 95% CI 0.63 to 4.01, five trials), neonatal unit admissions (OR 1.06, 95% CI 0.70 to 1.62, three trials), or neonatal infection rates (OR 2.01, 95% CI 0.50 to 8.07, five trials).A lack of data for some comparisons prevented robust conclusions. Further research is needed.

AUTHORS' CONCLUSIONS

Evidence suggests that water immersion during the first stage of labour reduces the use of epidural/spinal analgesia. There is limited information for other outcomes related to water use during the first and second stages of labour, due to intervention and outcome variability. There is no evidence of increased adverse effects to the fetus/neonate or woman from labouring in water or waterbirth. The fact that use of water immersion in labour and birth is now a widely available care option for women threatens the feasibility of a large, multicentre randomised controlled trial.