Editing Pediatric Nursing (section)

== Physical growth parameters ==

=== Weight ===

* Newborns lose up to 10 percent of birth weight in the first few days of life and regain it by about 2 weeks of age. Loss beyond 10 percent, or failure to regain by 2 weeks, requires evaluation.
* Birth weight '''doubles by about 4 to 6 months''' and '''triples by 12 months'''.
* Weight roughly quadruples by 2 to 2.5 years.
* After the toddler years, children gain approximately 2 to 3 kg per year until the pubertal growth spurt.

=== Length and height ===

* Birth length increases by about 50 percent by 12 months.
* Height roughly doubles by 4 years of age.
* Length is measured recumbent until age 2 or 3; after that, standing height is measured.

=== Head circumference and fontanels ===

* Head circumference is measured at the widest point, just above the eyebrows and over the occipital prominence, and is routinely tracked through 36 months.
* Head circumference '''exceeds chest circumference until about 12 months''', at which point they are approximately equal; after that, chest circumference exceeds head circumference.
* The '''posterior fontanel closes at 2 to 3 months'''.
* The '''anterior fontanel closes at 12 to 18 months'''.

'''Application note.''' A '''bulging, tense fontanel''' in a quiet infant suggests increased intracranial pressure and is an urgent finding. A '''sunken fontanel''' suggests dehydration. Transient bulging with crying, coughing, or vomiting is normal. A fontanel that has not closed by 18 months, or a head circumference crossing percentile lines upward, warrants referral for possible hydrocephalus.

=== Dentition ===

* First primary teeth typically erupt at 6 to 8 months, beginning with the lower central incisors.
* A rough estimate for the number of primary teeth in the first two years is age in months minus 6.
* All 20 primary teeth are usually present by 30 months.
* The first dental visit is recommended by 12 months or within 6 months of the first tooth.