The Effects of a Yoga Exercise and Nutritional Guidance Program on Pregnancy Outcomes Among Healthy Pregnant Japanese Women: A Study Protocol for a Randomized Controlled Trial

Objectives: This report provides an experimental protocol for a study designed to verify the effects of yoga exercise and a nutritional guidance program during pregnancy on several key pregnancy and birth outcomes among Japanese women. Design: This is a study protocol of a randomized controlled trial. Setting/Location: This intervention will be carried out in a university hospital in Tokyo. Subjects: Healthy primiparous women will be recruited at 18–23 gestational weeks in the hospital. A total of 400 participants will be randomly assigned to one of four groups in this trial, with 100 participants in each group—group with yoga exercise, with nutritional guidance, with both yoga and nutritional guidance, and with standard care alone, as the control group. Yoga exercise consists of yoga classes held at the hospital 3 or 5 days a month, duration 60 min, and home practice using a digital video disk, duration 30 or 60 min per session. We recommend participants do yoga at least 3 days a week for a total of 60 min per day. Nutritional guidance is based on individual dietary intake assessed using a brief-type diet history questionnaire. Results: The primary outcome is rate of pregnant women with adequate gestational weight gain. Secondary outcomes include physiologic and psychologic status assessed via biomarkers and health-related scales, dietary nutrition intake, and birth outcomes. Conclusions: This study shows the effects of a yoga exercise and nutritional intervention. If the intervention is found to be effective, our results will be useful for healthcare providers and pregnant women.