Question: how much weight should my baby gain by 8 weeks?
Answer: From birth to age 6 months, a baby might grow 1/2 to 1 inch (about 1.5 to 2.5 centimeters) a month and gain 5 to 7 ounces (about 140 to 200 grams) a week. Expect your baby to double his or her birth weight by about age 5 months.