Involution of the uterus occurring with contractions of the uterine smooth muscle, whereby the uterus returns to its prepregnant state. The uterus also rapidly decreases in size from approximately 1000g (2.2 lb) to 50-60 g over 6 weeks with the fundal height descending into the pelvis approx. one finger breadth (1cm) per day.
A) Involution step
B) Contraction step
C) Fundal step
D) Descent step