Related Experiment Videos
Insights
Infant birthweight typically doubles by 3.8 months, earlier than commonly believed. Bottle-fed babies and boys reach this milestone sooner, highlighting potential early obesity risks with certain feeding practices.
Area of Science:
- Pediatrics
- Neonatology
- Human Growth and Development
Background:
- Infant birthweight doubling is a key growth indicator.
- Current estimates suggest this occurs between 5-6 months.
- Understanding factors influencing this growth is crucial for infant health.
Purpose of the Study:
- To accurately determine the age of birthweight doubling in infants.
- To identify key variables associated with birthweight doubling time.
- To assess potential implications for infant growth patterns and obesity risk.
Main Methods:
- Study included 357 healthy infants with birthweights between 2,500 and 4,100 grams.
- Data collected on feeding method (bottle vs. breast) and gender.
- Age of birthweight doubling was recorded and analyzed.
- Introduction of solid foods was noted.
Main Results:
- Mean age for birthweight doubling was 119 days (3.8 months).
- Bottle-fed infants (113 days) doubled weight earlier than breast-fed infants (124 days).
- Boys (111 days) doubled weight earlier than girls (129 days).
- Solids introduced earlier in bottle-fed (1.9 months) vs. breast-fed (3.9 months) infants.
Conclusions:
- Infant birthweight doubling occurs earlier than commonly cited.
- Feeding method and gender significantly impact growth velocity.
- Bottle-fed infants show accelerated weight gain relative to length, suggesting potential early obesity.
- Closer monitoring of infant feeding practices is recommended to mitigate obesity risks.
Abstract:
Infant birthweight doubling time is widely quoted as being achieved between 5 and 6 months. The purpose of this study was to determine the time of birthweight doubling and to identify important related variables. A total of 357 normal infants with birthweights between 2,500 and 4,100 gm were studied. Mean age of birthweight doubling for the entire group was 119 days (3.8 months). Bottle-fed infants doubled their birthweights earlier than breast-fed infants: 113 days vs. 124 days (P less than .05). Boys doubled their birthweights earlier than girls: 111 days vs. 129 days (P less than .0001). Solids were introduced earlier in bottle-fed infants (mean , 1.9 months) than in breast-fed infants (mean, 3.9 months). Harvard percentiles for mean group weight and length at the time of birthweight doubling were: for bottle-fed infants, 75th and 55th percentiles respectively: for breast-fed infants, 55th and 60th percentiles respectively; for boys, 75th percentile for both weight and length; for girls, 50th percentile for both weight and length. Thus, bottle-fed infants appear to have weight gains in excess of length gain and may be developing early obesity. In light of the poor prognosis in treating obesity, closer supervision of early infant feeding practices is indicated.