What term describes the gradual reduction in size of the uterus after delivery as it contracts to return to its normal size?

• A. Involution
• B. Hyperplasia
• C. Atony
• D. Dysplasia

Answer: (A)

Involution describes the uterus returning to its pre-pregnant size after delivery as it contracts. After the placenta is delivered, the myometrium contracts and the placental site heals, gradually shrinking the uterus from about its enlarged pregnancy size back toward normal. Clinically, the fundus typically descends about one fingerbreadth per day, and by about six weeks postpartum the uterus has mostly returned to its nonpregnant size, though timelines can vary. This process is helped by uterotonic hormones like oxytocin and prostaglandins and is essential for minimizing postpartum bleeding.

Other terms don’t fit this specific process: hyperplasia is an increase in cell number, not the size reduction after delivery; atony is a failure of the uterus to contract; dysplasia refers to abnormal tissue development.