What is the expected time course for involution of the uterus after delivery?

• A. The uterus remains enlarged for two months
• B. The uterus descends about 1 fingerbreadth per day; involution is usually complete by about 6 weeks postpartum
• C. The uterus ascends during the first week
• D. The uterus reduces by 3 cm per day

Answer: (B)

After delivery, the uterus undergoes involution as the myometrium contracts and the placental site heals, returning to its pre-pregnant size. The fundus is at the level of the umbilicus right after birth and then slowly descends about one fingerbreadth (roughly 1 cm) each day. By about six weeks postpartum, the uterus is typically back to its nonpregnant size and position. This pace explains why the best answer is the one describing a daily descent of about a fingerbreadth and completion around six weeks. The other statements don’t fit the normal course: the uterus does not ascend in the first week, it does not shrink that rapidly (3 cm per day), and it does not remain enlarged for two months.