All of the following represent normal physiology of the newborn except

All of the following represent normal physiology of the newborn except

• A. Weight of 2.4 kg
• B. Immature liver function and inability to eliminate excess bilirubin
• C. Closure of the ductus arteriosus and a shift of blood flow through the heart
• D. 4 to 6 months for the infant's body weight to double

Answer: (A)

In newborn physiology, several adaptations are expected right after birth. A healthy term infant normally shows a typical weight range, a liver that is still maturing enough to cause physiologic jaundice, and a circulatory transition where the ductus arteriosus closes and blood flow shifts to support the lungs for oxygen exchange. Growth milestones also follow predictable patterns, such as doubling birth weight by about four to six months. The statement about a birth weight of 2.4 kg does not fit with the usual physiologic expectations for a term newborn. Term babies commonly weigh around 3.0 kg, with many in the 2.5–4.0 kg range; 2.4 kg is considered low birth weight and is not a normal physiological process of newborn adaptation. It signals that additional factors, such as prematurity or growth restriction, may be involved. The other statements describe normal newborn physiology: immature liver function leading to physiologic jaundice is typical in the first days of life, the ductus arteriosus closing and circulation shifting to neonatal patterns is a standard postnatal transition, and most infants double their birth weight by four to six months, which matches expected growth.

In newborn physiology, several adaptations are expected right after birth. A healthy term infant normally shows a typical weight range, a liver that is still maturing enough to cause physiologic jaundice, and a circulatory transition where the ductus arteriosus closes and blood flow shifts to support the lungs for oxygen exchange. Growth milestones also follow predictable patterns, such as doubling birth weight by about four to six months.

The statement about a birth weight of 2.4 kg does not fit with the usual physiologic expectations for a term newborn. Term babies commonly weigh around 3.0 kg, with many in the 2.5–4.0 kg range; 2.4 kg is considered low birth weight and is not a normal physiological process of newborn adaptation. It signals that additional factors, such as prematurity or growth restriction, may be involved.

The other statements describe normal newborn physiology: immature liver function leading to physiologic jaundice is typical in the first days of life, the ductus arteriosus closing and circulation shifting to neonatal patterns is a standard postnatal transition, and most infants double their birth weight by four to six months, which matches expected growth.