Women giving birth face trade-offs between effectiveness and adverse effects of drugs or nonpharmaceutical approaches when choosing a pain relief strategy, according to a new analysis published by The Cochrane Library. Drugs appear more likely than alternative approaches to curb pain but are also more likely to be associated with adverse effects, while some nondrug approaches offer fewer adverse effects but their effectiveness is far less certain.
Women have an array of choices for pain management during labor—from drugs that may alleviate pain to nondrug approaches for making pain easier to tolerate—but the evidence supporting each varies. And women would like better information to guide their choices. In fact, 78% of consumers participating in a Cochrane Collaboration effort to identify research priorities in pregnancy and childbirth identified pain relief during labor as the most important topic. So a team of scientists analyzed data from more than 300 trials of such interventions to assess which have the strongest support.
The researchers classified methods for relieving labor pain into 3 categories based on the evidence base to date: those that clearly work, those that may work, and interventions that lack enough evidence to say one way or the other. Epidural, inhaled analgesia, and combined spinal epidural were in the first category, with the largest and strongest evidence base. Unfortunately, this group of approaches was also associated with the most adverse events. These included vomiting and dizziness among women receiving inhaled analgesia; low blood pressure, motor blockade, fever, or urine retention among women with epidural analgesia; and more vaginal deliveries requiring instrumental assistance and more cesarean deliveries for fetal distress (but not more cesarean deliveries overall) among women receiving epidural analgesia.
Immersion in water, relaxation, acupuncture, massage, and local anesthetic nerve blocks or nonopioid drugs may work, according to the analysis, with fewer adverse effects, but the evidence for effectiveness was limited, with only 1 trial each for most of these interventions. Interventions for which there was insufficient evidence to determine whether they effectively relieved labor pain included hypnosis, biofeedback, sterile water injection, aromatherapy, transcutaneous electrical nerve stimulation, or parenteral opioids.
“Women should be told about the benefits and adverse effects of different pain relief methods but should feel free to choose whatever form of pain relief they feel would help them most during labor,” said lead author of the study, James Neilson, MD, of the Department of Women’s and Children’s Health at the University of Liverpool in Liverpool, United Kingdom. “It remains important to tailor approaches to women’s individual needs and circumstances.”