Weight of a newborn quadruples at –
**Core Concept**
The weight of a newborn infant increases significantly in the first few months of life due to rapid growth and development. This growth pattern is influenced by various physiological processes, including cellular proliferation, differentiation, and organ maturation.
**Why the Correct Answer is Right**
Weight gain in newborns is a well-documented phenomenon, and by 3-4 months of age, the infant's weight typically quadruples from birth. This rapid growth is driven by the infant's increasing caloric intake, as well as the mobilization of stored energy reserves. The growth pattern is influenced by the hypothalamic-pituitary-adrenal (HPA) axis, which regulates the release of growth hormone and other hormones that promote growth and development.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the weight of a newborn does not double by 1-2 months of age. While there is some weight gain during this period, it is not sufficient to double the birth weight.
* **Option B:** This option is incorrect because the weight of a newborn does not triple by 2-3 months of age. While there is significant weight gain during this period, it is not sufficient to triple the birth weight.
* **Option C:** This option is incorrect because the weight of a newborn does not reach adult levels by 1 year of age. While there is significant growth and development during the first year, it is not sufficient to reach adult weight levels.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the growth pattern of infants can vary significantly, and not all infants will quadruple their birth weight by 3-4 months of age. Factors such as prematurity, genetic disorders, and nutritional deficiencies can affect growth and development.
**Correct Answer:** C. By 3-4 months of age, the infant's weight typically quadruples from birth.