Prenatal Yoga May Result in Less Labor Pain, Shorter Labor

Chuntharapat, S., Petpichetchian, W., & Hatthakit, U. (2008). Yoga during pregnancy: Effects on maternal comfort, labor pain and birth outcomes. Complementary Therapies in Clinical Practice, 14(2), 105-115. [Abstract]

Summary: In this trial conducted in Thailand, nulliparous pregnant women without previous yoga experience were randomly assigned to practice prenatal yoga (n=37) or to usual care (n=37). The yoga group attended a series of six 1-hour yoga classes every two weeks in the final trimester and were given a booklet and audio tape for self-study, which they were encouraged to practice at least three times per week. Daily diaries kept by participants and weekly phone contact from researchers helped ensure compliance. Participants in both groups completed a prenatal questionnaire to assess anxiety and collect demographic data.

Once in labor, pain and comfort were assessed every 2 hours in the first stage of labor (for a maximum of three measurements) and again 2 hours postpartum using multiple pain-measurement instruments that have previously been validated for use in laboring women. The researchers controlled for maternal age, marital status, education level, religion, income, and maternal trait anxiety.

Data were available for 33 of 37 women assigned to each group but the researchers provide no explanation for this attrition. Although this omission limits the reliability of the study, the strength and consistency of the researchers' findings suggest that attrition probably did not significantly alter results. The experimental group (yoga group) had significantly less pain and more comfort than the control group at each of the three measurement intervals during labor and at the postpartum measurement. This finding was consistent and significant across all three pain main measurement instruments used.

The researchers do not present data about mode of birth. However, the length of the first stage of labor and total duration of labor were significantly shorter in the yoga group (mean length of first stage = 520 minutes in yoga group versus 660 minutes in control group; mean total time in labor 559 minutes in yoga group versus 684 minutes in control group). There were no differences in length of second stage of labor, pethidine usage or dose given, augmentation of labor, newborn weight, or Apgar scores. Epidural analgesia was not mentioned so presumably it was not available.

Significance for Normal Birth: This study provides evidence that regular yoga practice in the last 10-12 weeks of pregnancy improves maternal comfort in labor and may facilitate labor progress. The researchers offer several theories for these effects. First, yoga involves synchronization of breathing awareness and muscle relaxation which decrease tension and the perception of pain. Second, yoga movements, breathing, and chanting may increase circulating endorphins and serotonin, "raising the threshold of mind-body relationship to pain" (p. 112). Third, practicing yoga postures over time alters pain pathways through the parasympathetic nervous system, decreasing one's need to actively respond to unpleasant physical sensations.

Prenatal strategies that help women prepare emotionally and physically for labor may help reduce pain and suffering and optimize wellbeing in childbirth by providing coping skills and increasing self-confidence and a sense of mastery. More research is needed to confirm the findings of this study. However, yoga's many health benefits and the lack of evidence that yoga is harmful in pregnancy or birth provide justification for encouraging interested women to incorporate yoga into their preparations for childbirth.