Pain Management for Women in Labor: A Research Review
As part of the Cochrane Collaboration, Leanne Jones and eight of her colleagues (2012) has published new research synthesizing divergent data constructs and summarizing 355 trials on pain management during childbirth. There are many detailed data tables associated with this study.
To view the entire study, Lamaze members can access the full Cochrane Library, via the Members Only Section.
A summary of the study is below.
In 2007, the Cochrane Pregnancy & Childbirth Group (PCG) consumer’s group identified pain relief in childbirth as the topic of most importance to them.
This study was funded to provide an evidence-based summary of the efficacy and safety of pain management methods in childbirth for consumers, policy-makers, and childbirth educators.
Women experience pain in childbirth in varying degrees of intensity, influenced by physiological and psychosocial factors. Most women require some type of pain relief. Both non-pharmacological and pharmacological methods are used for pain management.
312 Studies Reviewed
Collecting the totality of evidence from existing randomized controlled trials, the researchers identified 18 total systematic reviews for inclusion in their study. 15 reviews were Cochrane reviews (257 included trials) and 3 were non-Cochrane reviews (55 included trials). Data from a total of 312 studies were reviewed in this study.
There were more studies of pharmacological interventions than non-pharmacological interventions.
13 Outcomes Identified for Inclusion
The researchers, in partnership with the PCG consumer group, identified these outcomes for inclusion in the study.
Effects of interventions
- Pain intensity (as defined by trialists)
- Satisfaction with pain relief (as defined by trialists)
- Sense of control in labor (as defined by trialists)
- Satisfaction with childbirth experience (as defined by trialists)
Safety of interventions
- Effect (negative) on mother/baby interaction
- Breastfeeding (at specified time points)
- Assisted vaginal birth
- Cesarean section
- Adverse effects (for women & babies)
- Admission to special care baby unit / NICU
- Apgar score less than at five minutes
- Poor infant outcomes at long-term follow-up (as defined by trialists)
15 Childbirth Management Methods Identified
The researchers identified a list of 15 childbirth pain management methods:
- placebo/no treatment
- intracutaneous or subcutaneous sterile water injection
- immersion in water
- relaxation techniques (yoga, music, audio)
- acupuncture or acupressure
- massage, reflexology or manual methods
- inhaled analgesia
- non-opioid drugs
- local anesthetic nerve blocks
As a Lamaze childbirth educator, how will you incorporate respect for your client’s individual decisions while presenting the Six Lamaze Healthy Birth Practices?
Results: Non-pharmacological Studies
The authors found that non-pharmacological methods are mostly used in midwife-led continuity of care births and/or where women had continuous intrapartum support. Such non-pharmacological methods are meant to break the fear-pain-tension cycle and to work within the pain paradigm. The pain paradigm of birth is a philosophy based on the idea that pain is a normal part of the physiology of labor and that women can use coping methods to manage the pain (Leap, 2008; as cited in Jones et al, 2012).
The researchers found the evidence for many non-pharmacological methods to be mostly incomplete as there is an average of only two studies for each method.
However, the following non-pharmacological methods are shown to provide pain relief and positive maternal psychological outcomes without invasive side effects: immersion in water, relaxation, acupuncture/acupressure and massage.
In addition, women report greater emotional satisfaction with childbirth when using immersion and relaxation. With the use of relaxation and acupuncture/acupressure, there is a decrease in the use of forceps and ventouse. There is a decrease in the amount of cesarean section associated with the use of acupuncture/acupressure.
The researchers report there is insufficient evidence to report on pain relief using the following methods: hypnosis, biofeedback, sterile water injection, aromatherapy and TENS.
Results: Pharmacological Studies
There are more studies of pharmacological methods versus non-pharmacological methods. The authors found that pharmacological methods relieve pain and have side effects.
Pharmacological methods are most likely to be used in settings with a pain relief paradigm. In the pain relief paradigm of labor, pain is considered barbaric, the benefits of analgesia outweigh the risks, and women should be free to use whatever pain relief methods she wishes, without guilt (Leap, 2008; as cited in Jones et al, 2012).
Comparative Pain Relief & Side Effects
Epidural, combined spinal epidural (CSE) and inhaled nitrous oxide & oxygen relieve pain better when compared to opioids (Jones et al, 2012).
Epidurals are associated with an increase of the use of forceps or ventouse, an increase in the risk of low blood pressure, low motor blocks, fever and urine retention (Amin-Somanuh, 2005; as cited in Jones et al, 2012). In addition, other side effects such as shivering, tinnitus, and respiratory or cardiovascular depression may occur. The authors state it is uncertain whether the use of epidurals interfere with breastfeeding (Reynolds, 2011; as cited in Jones et al, 2012).
Combined spinal epidurals (CSE) provide faster pain relief than traditional epidurals, but are associated with more feelings of itchiness, giddiness, sweating, and tingling (Jones et al, 2012).
Inhaled nitrous oxide is associated with minimal toxicity and rapid maternal and neonate elimination, but can cause feelings of nausea, drowsiness and sickness (KNOV, 2009; Rosen, 2002; as cited in Jones et al, 2012).
Non-opioid drugs (acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDS)) relieve pain for shorter periods of time as compared to opioid drugs (Bayarski, Hebbes, 200; as cited in Jones et al, 2012).
Opioid drugs (morphine, nalbuphine, fentanyl, parenteral and pethidine) are used worldwide. Parenteral opioids are reported to provide less pain relief than epidurals. Side-effects include impaired maternal capacity for decision-making, sedation, hypoventilation, hypotension and urine retention. Opioids readily cross the placenta, thus neonatal respiratory depression and hypothermia are also concerns. Pethidine is shown to affect fetal heart rate variability during labor (Sekhavat, 2009; Solt, 2002; as cited in Jones et al, 2012), thus continuous fetal monitoring is recommended. Neonatal effects are inhibited and early cessation of breastfeeding and decreased alertness (Nissen, 1995; Ransjo-Arvidsen, 2001; Righard, 1990; Rajan, 1994; as cited in Jones et al, 2012).
Limitations Found in the Studies
The authors state the studies use differing methods to measure pain management outcomes. Many do not at all measure maternal psychological outcomes (feelings of intrinsic self-control), mom-baby interaction, or breastfeeding and infant outcomes.
This study shows consumers rate pain management as a high priority in childbirth, however, after 30 years of research, standardized pain management and outcome measurements have not been created.
The authors suggest their outcome guidelines, developed with consumer input, be adopted for use in future research.
Overall, women should feel free to choose whatever methods of pain relief they wish, both non-pharmacological and pharmacological, for their individual childbirth experience.
As part of a childbirth preparation program, women should be informed of the efficacy and potential side-effects on both themselves and their babies of non-pharmacological and pharmacological methods of pain relief for childbirth.
Hopefully this study will generate an effort to standardize the constructs associated with research of measurements of pain management in labor, maternal psychosocial satisfaction, and maternal-baby outcomes.
Jones L, Othman M, Dowswell T, Alfirevic Z, Gates S, Newburn M, Jordan S, Lavender T, Neilson JP. Pain management for women in labour: an overview of systematic reviews. Cochrane Database of Systematic Reviews 2012, Issue 3. Art. No.: CD009234. DOI: 10.1002/14651858.CD009234.pub2
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