Yoga has much to offer moms-to-be: calming breathing and deep relaxation techniques; toning for buttocks and thigh muscles (making it easier to carry extra weight and to deliver in a squatting position); strengthening of the pelvic floor muscles (used in childbirth); help for some pregnancy-specific aches and pains, like lower back pain, and possibly edema.
Other bonuses include increased flexibility and stamina and improved balance and posture, says Jnani Chapman, executive director of the International Association of Yoga Therapists, in Mill Valley, CA. Plus, it's a safe form of exercise for most expectant women, although if you have a history of problems such as diabetes, hypertension, or miscarriage, you should avoid it.
Whether you join a regular yoga class or a prenatal one, a teacher trained in prenatal yoga can demonstrate postures that take your pregnancy into account. Twisting movements, back bends, and strenuous standing poses are generally ruled out. You're more likely to use a pillow, wall, or chair for support. And rather than lying on your back, which can be uncomfortable, you'll learn variations to try on your side.
A caveat: The hormone that relaxes ligaments and tendons -- widening the pelvis for birth -- makes some postures easier during pregnancy than before. Use that extra flexibility with care: Never force your body in a way that you suspect could cause injury.