What is the expected daily weight gain in grams for a newborn?

Expected Daily Weight Gain for Newborns

Newborns should gain 17-20 grams per kilogram per day (g/kg/day) to maintain appropriate growth trajectories and prevent dropping across weight centiles. 1

Weight Gain Targets by Population

Term Newborns (≥37 weeks)

• Target: 17-20 g/kg/day to match appropriate growth trajectories 1
• This translates to approximately 20-30 grams per day (or about 1 oz daily) for an average-sized term infant 2
• Weight gain below 9 g/kg/day is significantly below target and requires immediate intervention 1, 3

Preterm Infants

The expected weight gain varies by gestational age and birth weight:

• Very preterm infants (23-27 weeks): A growth velocity of 20-30 g/kg/day is associated with maintaining or exceeding birth weight z-scores, with rates at the upper end of this range needed for the most premature infants 4
• Preterm infants 1000-1500g birth weight: Growth velocity of 20-30 g/day up to 20 weeks of age when exclusively breastfed 5
• Preterm infants 1501-2000g birth weight: Growth velocity of 30 g/day up to 11 weeks, then 20 g/day after 12 weeks 5
• The commonly cited 15 g/kg/day rate only fits growth references for limited time periods (approximately 34 weeks gestation), with higher rates needed earlier and lower rates acceptable at older ages 6

Critical Time Periods

First Two Weeks

• Newborns typically lose weight initially, then should regain birth weight by 7-10 days after birth 7
• Healthy term infants show median time to recover birth weight around 6.5 days (formula-fed) to 8.3 days (breastfed) 7
• Minimal or no weight gain during the first two weeks warrants prompt evaluation 1
• If birth weight is not regained by 12-14 days, pathology must be carefully excluded and feeding regime checked 7

After Birth Weight Recovery (Stable Growth Phase)

• Once birth weight is regained, consistent daily weight gain of 17-20 g/kg/day should be maintained 1
• This rate prevents infants from dropping across weight centiles on growth charts 1

When Intervention Is Required

Immediate evaluation and intervention are needed when: 1, 3

• Weight gain falls below 17-20 g/kg/day target
• Infant falls below the 2.3rd percentile on WHO growth charts
• Weight gain is only 9 g/kg/day or less
• Minimal or no weight gain during first two weeks of life

Catch-Up Growth Targets

• Initial caloric target for inadequate weight gain: approximately 120 kcal/kg/day to promote catch-up weight gain 1, 3
• For infants with chronic conditions, caloric needs may increase to 150 kcal/kg/day or more 3

Common Pitfalls to Avoid

• Do not wait too long to intervene when weight gain is inadequate, as this can lead to impaired neurodevelopment and increased severity of other health issues 1, 3
• Do not supplement breastfed infants with formula simply because they appear to be growing more slowly than WHO curves during the first 3 months; first assess lactation adequacy, maternal nutrition, and feeding technique 1
• Do not use CDC charts for infants under 24 months; WHO growth charts are the gold standard and represent optimal growth patterns 1
• Do not assume 15 g/kg/day is appropriate for all preterm infants; younger gestational ages require higher rates (20-30 g/kg/day) 4, 6

Monitoring Schedule

• Schedule weight checks within 48-72 hours after initiating interventions to assess response 1
• For ongoing concerns, schedule more frequent weight checks every 2-4 weeks 1
• Serial measurements of weight, length, and head circumference should be performed to determine adequacy of nutritional support 3