Physical Growth and Vital Signs

Infancy involves rapid physical maturation. Newborns may lose up to 10% of their birth weight but regain it by 10 to 14 days. Weight doubles by 4 to 6 months and triples by 1 year,. The posterior fontanel closes by 2 months, while the anterior closes by 12 to 18 months.

Vital Signs by Age:

• Heart Rate: Newborn (110–160/min); Infant (90–160/min).

• Respirations: Newborn (30–60/min); Infant (25–60/min).

• Blood Pressure (Average): Newborn (64/41 mm Hg); Infant (85/50 mm Hg).

• Temperature: Ranges from 37.5°C (99.5°F) at 3 months to 37.7°C (99.9°F) at 1 year (axillary/rectal routes preferred).

Pain Assessment: Nurses should use age-appropria ...