OBJECTIVES: The purpose of this article is to review all randomized control trials (RCTs) that have looked at the health effects of yoga on pregnancy, and to present their evidence on the specific ways in which pregnant women, and their infants can benefit from yoga intervention. The purpose is also to determine whether yoga intervention during pregnancy is more beneficial than other physical exercises. METHODS: Four databases were searched using the terms "yoga and (pregnancy or pregnant or prenatal or postnatal or postpartum)." Databases were searched from January 2004 to February 2014. RESULTS: Ten randomized controlled trials were evaluated. The findings consistently indicate that yoga intervention presented with lower incidences of prenatal disorders (p ≤ 0.05), and small gestational age (p < 0.05), lower levels of pain and stress (p < 0.05), and higher score of relationship (p < 0.05). In addition, yoga can be safely used for pregnant women who are depressed, at high-risk, or experience lumbopelvic pain. Moreover, yoga is a more effective exercise than walking or standard prenatal exercises. CONCLUSIONS: The findings suggest that yoga is a safe and more effective intervention during pregnancy. However, further RCTs are needed to provide firmer evidence regarding the utility and validity of yoga intervention.