Effects of yoga on utero-fetal-placental circulation in high-risk pregnancy: a randomized controlled trial.

Introduction. Impaired placentation and inadequate trophoblast invasion have been associated with the etiology of many pregnancy complications and have been correlated with the first trimester uterine artery resistance. Previous studies have shown the benefits of yoga in improving pregnancy outcomes and those of yogic visualization in revitalizing the human tissues. Methods. 59 high-risk pregnant women were randomized into yoga (n = 27) and control (n = 32) groups. The yoga group received standard care plus yoga sessions (1 hour/day, 3 times/week), from 12th to 28th week of gestation. The control group received standard care plus conventional antenatal exercises (walking). Measurements were assessed at 12th, 20th, and 28th weeks of gestation. Results. RM-ANOVA showed significantly higher values in the yoga group (28th week) for biparietal diameter (P = 0.001), head circumference (P = 0.002), femur length (P = 0.005), and estimated fetal weight (P = 0.019). The resistance index in the right uterine artery (P = 0.01), umbilical artery (P = 0.011), and fetal middle cerebral artery (P = 0.048) showed significantly lower impedance in the yoga group. Conclusion. The results of this first randomized study of yoga in high-risk pregnancy suggest that guided yogic practices and visualization can improve the intrauterine fetal growth and the utero-fetal-placental circulation.