3.2: Growth Trends for Newborns and Infants
- Page ID
- 245007
This page is a draft and is under active development.
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Newborns experience rapid growth in their first few months of life. As they develop in a rapid pace, they rely on caregivers to take care of thier daily needs.
Weight
- Initial Weight Loss: It's normal for newborns to lose about 5-10% of their birth weight in the first few days due to fluid loss.
- Weight Regain: Most babies regain their birth weight by 10-14 days old.
- Rapid Gain: For the first month, the average weight gain is about 1 ounce (30 grams) per day or 4-8 ounces (110-230 grams) per week.
- Doubling Birth Weight: Most babies double their birth weight by around 5-6 months.
- Tripling Birth Weight: By their first birthday, most healthy newborns will have tripled their birth weight.
- Slower Gain After 6 Months: The rate of weight gain typically slows down in the second six months.
Length (Height)
- Average Length at Birth: The average length of a full-term newborn is about 19-20 inches (48-50 cm), with a typical range of 18-22 inches (45.7 to 56 cm).
- Rapid Growth in First Month: In the first month, babies typically grow about 1-1.5 inches (2.5-3.8 cm) in length.
- Growth in the First 6 Months: Babies tend to grow about 1 inch (2.5 cm) per month during the first six months.
- Slower Growth in the Second 6 Months: From 7 to 12 months, the growth rate in length decreases to about 0.5 inches (1.3 cm) per month.
- Increased by 50% by Age 1: Most babies increase their birth length by about 50% by their first birthday, growing around 10 inches (25 cm).
Head Circumference
- Average at Birth: The average head circumference of a full-term newborn is around 13.5 inches (34 cm).
- Rapid Growth: Head circumference increases rapidly in the first few months to accommodate the growing brain.
- Growth in the First Month: The head circumference may increase by about 1 inch (2.5 cm) in the first month.
- Growth in the First 3 Months: The average increase is about 0.5 inches (1.5 cm) per month for the first three months.
- Slower Growth: The rate of head growth slows down after the first few months.
The Role of Nutrition
- First 6 Months:
- Breast Milk: Breast milk is the ideal food for newborns, providing all the necessary nutrients in easily digestible form, along with antibodies for immunity. It adapts to the baby's changing needs.
- Formula: Iron-fortified infant formula is a healthy alternative when breastfeeding is not possible. It is designed to mimic the nutritional content of breast milk.
- Feeding Frequency: Newborns typically need 8-12 feedings per day (every 2-3 hours). Feeding should be "on cue," responding to the baby's hunger signs (rooting, sucking on hands, lip-smacking, and crying as a late sign).
- Vitamin D Supplementation: Breastfed babies need supplemental Vitamin D soon after birth as breast milk alone may not provide enough. Formula is typically fortified with Vitamin D. Consult your pediatrician for recommendations.
- No other fluids: Healthy newborns don't need water, juice, or other fluids in the first 6 months unless specifically advised by a doctor.
After 6 Months (Introduction of Solids):
- Complementary foods are introduced alongside breast milk or formula to provide additional nutrients.
- Start with nutrient-dense foods, including iron and zinc-rich options like fortified infant cereals, meat, and beans.
- Introduce potentially allergenic foods early and one at a time to monitor for reactions (e.g., eggs, cow's milk products, peanuts, tree nuts, wheat, shellfish, fish, soy).
- Avoid honey until after 1 year due to the risk of botulism.
- Limit or avoid foods and beverages with added sugars and high sodium content.
- Offer breast milk or formula until 1 year of age. Juice is not recommended for infants under 1 year.