lay the baby down and stretch a measuring tape from the top of the head to the bottom of the heel. In developed countries, the average birth weight of a full-term newborn is approximately 3.4 kg (7 1⁄2 lb), and is typically in the range of 2.7–4.6 kg (6.0–10.1 lb). Over the first 5–7 days following birth, the body weight of a term neonate decreases by 3–7%, and is largely a result of the resorption and urination of the fluid that initially fills the lungs, in addition to a delay of often a few days before breastfeeding becomes effective. After the first week, healthy term neonates should gain 10–20 grams/day. A newborn's head is very large in proportion to the body, and the cranium is enormous relative to his or her face. While the adult human skull is about one seventh of the total