Objective: To examine the acute maternal and fetal effects of yoga postures and suspected contraindicated postures in a prospective cohort of healthy pregnant women in the third trimester.

Methods: This was a prospective study that evaluated pregnant women between 35 0/7 and 37 6/7 weeks of gestation in a one-on-one yoga session. A baseline nonstress test, vital signs, and pulse oximetry were performed. Participants then assumed 26 yoga postures. Vital signs, pulse oximetry, tocometry, and continuous fetal heart rate monitoring were obtained in each posture. Postsession nonstress test, vital signs, and pulse oximetry were obtained. Participants were contacted 24 hours postsession.

Results: Twenty-five healthy pregnant women were evaluated. Ten reported regular yoga practice, eight were familiar with yoga, and seven had no yoga experience. Yoga groups were similar in age, race, body mass index, gestational age, and parity. Presession and postsession nonstress tests were reactive. Presession and postsession data showed no change in maternal heart rate, temperature, pulse oximetry, or fetal heart rate. During the 26 yoga postures, vital signs, pulse oximetry, and uterine tocometry remained normal in all women and in all postures. The fetal heart rate across all 26 postures was normal. There were no falls or injuries during the total cumulative 650 poses. No participants reported decreased fetal movement, contractions, leakage of fluid, or vaginal bleeding in the 24-hour follow-up.

Conclusion: All 26 yoga postures were well-tolerated with no acute adverse maternal physiologic or fetal heart rate changes.

Level of evidence: III.