Traditional Chinese Medicine has a long history and it’s been proved to work for pregnant mothers. Hand Acupressure is considered a derivative of this science.
I found this interesting image on the image, but unable to search the source of it.
Quoting from an article that I read online
The underlying theory is that there is an invisible force or energy, called qi in Chinese, which has healing power. There are many points, called acupoints or meridians, which connect to the glands of the body. In therapy, pressure is applied at specific points to increase the flow of the qi, in and around the body through the point network. Pressuring acupoints ensures normal qi circulation.