Here’s some key parts from an article I just read:

Time of Labor
The body’s balance and ability to function properly can have a huge impact on its capacity to adapt to extra stresses placed upon it. The most common cause of Cesarean in the United States is “failure to progress”. Any misalignment in the pelvic outlet could be a cause of slower descent of the fetus through the birth canal. Back pain could also decrease a mother’s rang of motion making it more difficult for her to assume the upright, active positions that have been proven to make labor more efficient. Proper adjustments can make sure that the hips and pelvis are in proper alignment.

Dr. Sears wrote in Parenting magazine “It is our personal theory that chiropractic care in pregnancy can help to avoid or relieve back pain and also prepare your back and pelvic structures for the stresses of labor and birth.”

Here’s the entire article.