Health Promotion and Maintenance

By about 5-6 months. Birth weight triples by 12 months. Slower gain may signal feeding problems or failure to thrive and should be reported.

By 2-3 months of age. It is small and triangular. Early or late closure can indicate skull or developmental problems and should be reported.

Between 12 and 18 months. A bulging fontanel suggests increased intracranial pressure; a sunken fontanel suggests dehydration — both must be reported.

Around 2 months. A social smile is a response to a caregiver's face or voice and is an early sign of normal social development.

Around 4-5 months (back to front by about 6 months). Because rolling can occur suddenly, caregivers should never leave an infant unattended on a raised surface — even before this milestone.

By about 8 months (many sit briefly unsupported at 6-7 months). Inability to sit unsupported by 9 months warrants developmental follow-up.