Inexpensive TENS Unit Can Ease Labor Pain
There are many ways to deal with the pain of giving birth, but women and their obstetricians can always benefit from having another choice. A Cochrane review has concluded that women in labor should have the option of using transcutaneous electrical nerve stimulation (TENS) — a non-drug method of pain management.
“There is only limited evidence that TENS reduces pain in labor and it does not seem to have any negative or positive impact on other outcomes for mothers and babies. However the majority of women in the reported studies have indicated that they would be willing to use TENS for a subsequent pregnancy,” said Tina Lavender, a review co-author and a professor of midwifery at the University of Manchester, in England.
Widely used in other areas of medicine, the TENS unit is a small device that emits low- voltage electrical pulses through electrodes attached to the body. The exact way the pulses work is unknown, but they are thought to block pain transmission by stimulating nerve pathways in the spinal cord. During labor, clinicians usually place the electrodes on the lower back, but they can also attach them at acupuncture points or to the head.
For the review, researchers analyzed 19 randomized controlled studies that examined the use of TENS during labor. The studies involved 1,671 women and occurred in 11 countries, with three studies in the United States. Fifteen studies examined TENS applied to the back, two to acupuncture points and two to the head. Studies compared TENS use to routine care, to the use of a sham TENS unit or to other types of pain management, either medications or other techniques.
Women in labor who received TENS were less likely to say they had severe pain compared to the other women. However, this difference was not great and was not consistent across the studies, nor did the studies show that women receiving TENS were more satisfied with their pain relief than those who did not use TENS.
The new review appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews like this one draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Lavender and her colleagues noted that it is possible that using TENS gave the women a feeling of control over their pain and served as a distraction. They concluded that women should have the option of using it during labor, with or without other forms of pain management.
No one has data on how widespread the use of TENS in obstetrics is, Lavender said, noting that one British study found that about 16 percent of low-risk women having their first baby used TENS during their labor. Generally, TENS works with other forms of pain management during labor, such as epidural anesthetics.
“TENS is not widely used in the U.S., largely because the pain relief offered is modest and TENS units are not frequently available on labor and delivery units,” said Laura Goetzl, M.D., an associate professor of obstetrics and oncology at the Medical University of South Carolina, in Charleston.
“There is no barrier to patients arranging for a TENS unit for themselves and using it in labor; however, the cost to the patient may not be worth the benefit over other treatments that are more likely to be covered by her insurance,” she said. Obstetricians usually support any method of pain relief a woman wants to use as long as it is not harmful to the mother or her baby and as long as it does not conflict with the policies of the admitting hospital, Goetzl said.
TENS units are not expensive, about 30 British pounds to rent and 50 pounds to buy in the United Kingdom, according to Lavender, and about $50 to $80 to rent for a week in the United States, according to an Internet search.