From the Guidelines
At 12 months, a healthy infant typically weighs around 9.6 kg for boys and 9.0 kg for girls, according to the World Health Organization (WHO) growth charts 1. The expected weight range for an infant at 12 months of age can vary, but generally falls between 7.7 to 11.3 kilograms. This range accounts for normal variations in growth patterns, with boys often weighing slightly more than girls on average. Key points to consider:
- The average weight for a 12-month-old boy is around 9.6 kg, while the average for girls is about 9.0 kg, as indicated by the WHO growth charts 1.
- Healthy growth isn't determined by weight alone but by consistent growth along the child's own curve.
- Some infants may weigh less or more than these averages and still be perfectly healthy.
- Regular check-ups with a pediatrician are essential to monitor your baby's growth pattern, using growth charts to track weight, length, and head circumference 1. If you're concerned about your baby's weight, it's best to consult with your pediatrician rather than focusing solely on average numbers, as they can assess your baby's overall health and development.
From the Research
Infant Weight at 12 Months
- The expected weight for an infant at 12 months of age is not explicitly stated in the provided studies 2, 3, 4, 5, 6.
- However, study 3 mentions that approximately 85% to 90% of infants were at a healthy weight-for-length (WFL) percentile at 12 months, but it does not provide specific weight values.
- Study 4 discusses the relationship between birth weight, growth, and feeding in infancy with serum lipid concentration at 12 months, but it does not provide average weight values for 12-month-old infants.
- Studies 5 and 6 focus on vitamin D intake and status, as well as feeding behaviors and weight-for-age at 12 months, but they do not provide specific expected weight values for infants at this age.
Factors Influencing Infant Weight
- Study 2 suggests that formula feeding is associated with rapid weight gain between 6 and 12 months of age, and that exceeding daily calorie requirements or overfeeding is associated with both formula amount and frequency of feeding 2.
- Study 3 found that parents of overweight infants often underestimate their child's weight status, and that mothers who are overweight are more likely to underestimate their child's weight status 3.
- Study 4 found that slower growth of high birth weight infants and breastfeeding contribute to higher total cholesterol concentration at 12 months, and that nutrient intake in infancy also affects lipid profile 4.
- Study 6 found that modifiable infant feeding behaviors, such as juice consumption, breastfeeding, and introduction to solid foods, contribute to weight-for-age at 12 months 6.