During inspiration, there occurs an acceleration of the heartbeat, a decrease in force of contraction of the heart muscle and an increase in the loudness of the heart sounds. (si.com)
I was so tired; I had no energy or willpower to push without the intense force of the contraction. (birthwithoutfearblog.com)
Fortunately, most doctors don't use forceps anymore, but the combination of increased weight from the baby, the force of contractions, and the type of labor and delivery a woman has all come into play to how her pelvic floor will be affected through pregnancy and delivery. (verywellfamily.com)