From the Guidelines
Newborns should gain 17-20 grams per kilogram per day to prevent growth failure. This recommendation is based on the most recent and highest quality study available, which suggests that aiming for a weight gain of 17-20 g/kg per day in very low birth weight infants is recommended to prevent dropping across weight centiles, i.e., growth failure 1. To determine the expected daily weight gain in grams for a newborn, we need to consider the baby's weight in kilograms. For example, a newborn weighing 3 kilograms should gain approximately 51-60 grams per day (17-20 g/kg per day). It is essential to note that this rate of weight gain is considered healthy and indicates adequate nutrition. After birth, babies often lose up to 10% of their birth weight in the first week, but should regain this by 10-14 days of age. The expected weight gain pattern then continues with most infants doubling their birth weight by 4-5 months and tripling it by one year. Adequate weight gain suggests the baby is receiving sufficient calories and nutrients from breast milk or formula. Parents should track their baby's weight at regular pediatric check-ups, as consistent weight gain along the growth curve is more important than any single measurement. If a baby consistently gains less than the recommended amount, this may warrant medical evaluation to rule out feeding problems or other health issues. In clinical practice, it is crucial to prioritize the single most recent and highest quality study, which in this case is the 2018 study published in Clinical Nutrition 1. This study provides strong evidence for the recommended weight gain range, and its findings should be used to guide clinical decision-making. By following this recommendation, healthcare providers can help ensure that newborns receive adequate nutrition and achieve healthy growth and development.
From the Research
Expected Daily Weight Gain for Newborns
The expected daily weight gain for newborns, particularly those who are preterm or low birth weight, can vary based on several factors including their diet (breast milk vs. formula), gestational age, and overall health.
- Studies have shown that formula-fed infants tend to have higher rates of weight gain compared to those fed donor breast milk 2.
- The average weight gain for formula-fed infants was found to be around 27.7 g/day, while those fed expressed breast milk (EBM) had an average weight gain of 17.2 g/day 3.
- Another study found that the mean growth rate for preterm very-low-birth-weight infants was approximately 16.2 g/kg/day, with an average time to regain birth weight of 14.2 days 4.
- For extremely low birthweight infants, an advisable daily weight gain of more than 15 g/kg per day was achieved by the sixth week of life, with a suggested nutritional intake that includes more than 100 mL milk/kg per day until the fourth week of life 5.
- A cohort study of very and extremely preterm babies in England and Wales found that weight velocity in all gestational age groups stabilized at around 34 weeks postmenstrual age at 16-25 g per day along parallel percentile lines, in babies surviving without major morbidity 6.
Key Findings
- Formula feeding is associated with higher rates of weight gain in preterm or low birth weight infants compared to donor breast milk 2.
- The recommended growth velocity for preterm infants is 10-15 g/kg/day, which can be achieved using unfortified expressed breast milk at higher feeding volumes 4.
- Extremely low birthweight infants may require a nutritional intake that includes more than 100 mL milk/kg per day until the fourth week of life to achieve a daily weight gain of more than 15 g/kg per day 5.