During the last trimester of pregnancy, the biggest concern – at least from my perspective – is the rapid growth and weight gain of the baby which exerts continually changing forces on the mother’s spine. Not only do the mother’s soft tissues have to expand (a lot) during delivery, but the bones in her pelvis must literally move apart. This process is assisted by increasing concentrations of the hormone relaxin in the final weeks of gestation. The baby does its part to prepare for delivery by orienting itself head down (usually) and by having un-fused skull bones which can literally overlap temporarily to decrease the circumference of the head during passage through the vaginal canal.
Needless to say, the final stages of pregnancy are extremely physically demanding. So the chiropractic goal for this time is to keep the mother’s lower back and pelvis as mobile as possible. Any areas of restriction could lead to increased pain and complication when delivery finally occurs. I usually recommend a pregnant woman come for treatment on about the same schedule as her pre-natal doctor visits. (Monthly at first then every two weeks for the second last month then weekly for the final month.)
I have treated dozens of women throughout their pregnancies, and I encourage all mothers-to-be to seek chiropractic care. It can make your experience a lot more comfortable and encourage a smooth delivery!