Catch-up Growth and Nutrition
for Premature Infants Postdischarge
Premature infants weight less than 2500 grams (g) and account for 7% of all live births.
They are born between 24 and 37 weeks of pregnancy and can weigh as little as 700 g.
From 24 weeks on, the fetus gains 30 g/day in utero, so every day is important to
increasing delivery weight.
Premature infants are too immature to feed directly from the breast or bottle until they are
32-34 biological weeks old. Breast milk is optimum for all infants, including infants born
prematurely. Once growth is established, nutritional needs of the preterm infant exceed
the content of human milk for protein, calcium, phosphorus, magnesium, sodium, zinc,
and vitamins. Breast-milk fortifiers and supplements are necessary, although no specific
protocols are available to determine when to discontinue their use. Some facilities
recommend using breast milk until the infant weighs at least 5 kilograms (kg).
Premature infants will require 100 to 120 kilocalories (kcal)/kg at time of discharge and
more if they are diagnosed with a lung disease or other condition that is known to
significantly impact nutritional needs, such as cystic fibrosis. Premature infants should
receive 3 to 4 g protein/kg/day.
The desired weight gain depends on the baby’s size, gestational age, and health. It may
amount to as little as 5 g/day for a baby at 24 weeks or 20 g/day for a larger baby at 33
weeks. In any case, a baby should gain about 0.25 ounce (oz)/day for every pound the
baby weighs (equal to 15 g/kg/day). Approximately 30% of preterm infants remain below
the 10th percentile for weight at 18 months and about 20% at 7 to 8 years of age.
Excessive weight gain after discharge from the hospital is correlated to obesity, diabetes,
and hypertension in adulthood. If they are eating adequately, infants should have six to
eight stools and six to eight wet diapers each day.
Premature infants should receive 1 milliliter (mL) of multivitamin solution each day until
they either weigh 3.5 to 4 kg or are taking 750 mL of infant formula each day. Until the
infant is 2 to 2.5 kg, they also should receive 50 to 65 micrograms (mcg) of folic acid
each day. Infants older than 2 months of age who are exclusively breastfeeding will
require 2 to 4 mg of elemental iron/kg of body weight each day until they are 1 year old.
Infants who are fed iron-fortified infant formula still may benefit from 1 milligram
(mg)/kg/day of elemental iron.
Breastfed infants should receive 200 international units (IU) of vitamin D/day from 2
months to 1 year of age. If a formula-fed infant is ingesting <500 mL of formula/day, the
infant should receive a supplement of 200 IU vitamin D/day. Most standard
multivitamins contain 400 IU vitamin D/mL.
Formula-fed premature infants who are <2000 g at discharge, diagnosed with osteopenia,
or are <3rd percentile for weight should receive a 24-kcal/oz formula with iron until they
weight 1850 g. At this point, you can switch to a 22-calorie/oz formula either until catch-
up growth is achieved or until the baby turns 1 year of age. If the patient is on a fluidrestricted diet, you may need to continue the more calorically dense formulas for a longer
period.
Formula-fed premature infants who are >2000 g at discharge or are >5th percentile for
weight can receive 22-kcal/oz formula with iron until catch-up growth is attained. At this
time, they can receive a standard 20-kcal/oz formula until they are 1 year of age (using
corrected age).
All formula-fed infants should receive 1 mL of multivitamins and 2 to 4 mg elemental
iron/kg of body weight until their intake is >32 oz/day. Formulas created for premature
infants generally are higher in calories, protein, calcium, phosphorus, zinc, vitamins, and
trace elements than standard formulas.
Nutritional deficiencies
Infants at the highest risk for nutritional deficiencies after discharge from the neonatal
intensive care unit include those who:
 Are extremely low birth weight (<1000 g) or very low birth weight (<1200 g)
 Are exclusively breastfed infants
 Require special formulas
 Require enteral nutrition at home
 Fail to gain 20 g/day prior to discharge
 Have gastrostomy tubes and/or tracheostomies
 Received total parenteral nutrition for >4 weeks
 Have a diagnosis of chronic renal insufficiency, congenital gastrointestinal anomalies,
cyanotic congenital heart disease, bronchopulmonary dysplasia, inborn errors of
metabolism, malabsorption, osteopenia, severe neurological impairment, or short bowel
syndrome, or are affected by poverty or low socioeconomic status
References and recommended readings
Ambat TC. Nutrition and growth in primary care of the premature infant.
http://www.ttuhsc.edu/fostersom/pediatrics/neonatology/documents/Postdischarge_nutriti
onal_tx.ppt. Accessed April 30, 2013.
Energy requirements of infants from birth to 12 months. Food and Agriculture
Organization of the United Nations Web site.
http://www.fao.org/docrep/007/y5686e/y5686e05.htm. Accessed April 30, 2013.
Feeding the premature infant: the NICU and beyond. Gerber® Web site.
http://medical.gerber.com/clinicaltopics/articles.aspx?articleId=4B37F07F-B9E3-4958B864-2BB7797F9D45&sec=articles&topicId=58c27ff3-fe25-4abb-9184-d03ad5718f89.
Accessed April 30, 2013.
Hilmers D. Nutrition in premature infants.
http://www.bcm.edu/medpeds/powerpoints/NutritionPreemie.pps#256. Accessed April
30, 2013.
Pediatric Nutrition Care Manual®. Academy of Nutrition and Dietetics Web site [by
subscription]. www.nutritioncaremanual.org. Accessed April 30, 2013.
US National Library of Medicine, National Institutes of Health. Neonatal weight gain and
nutrition. MedlinePlus Web site.
http://www.nlm.nih.gov/medlineplus/ency/article/007302.htm. Updated May 9, 2011.
Accessed April 30, 2013.
Ziegler EE. Protein requirements of very low birth weight infants. J Pediatr
Gastroenterol Nutr. 2007;45(suppl 3):S170-S174.
doi:10.1097/01.mpg.0000302966.75620.91
Review Date 4/13
K-0643