Incremental Growth/ Growth Velocity

Incremental growth measurements are useful when the infant is being followed at closely spaced intervals or when the infant's growth is so far from norms that it can't be followed using standard curves. (Desch,1994)

It is common practice to compare preterm infant's weight gain in the weeks after discharge by established hospital standards of 20-30 grams per day. Preterm infants who are showing catch-up growth may gain at greater rates than 20-30 g/d. Infants with medical conditions extremely low birth weight infants may not experience catch-up growth in the first 3 years or longer. Catch-up growth may not occur until school age.

Some infants may remain at lower growth percentiles even when plotted for corrected age, but rate of growth may be comparable to infants growing at normal percentiles.

In full-term, healthy infants the rate of growth falls during the first months of life. It is not clear what reasonable expectations for incremental growth in preterm infants should be. It is sometimes useful to assess whether the infant is at least meeting usual rates of growth for a term infant of equivalent corrected age. For example, a preterm infant at 6 months corrected age who is gaining 15 grams a day is gaining at rates that are within the norm for term infants. The following table is adapted from the work of Guo et al., 1991.

Weight Gain in Grams per Day in One Month Increments

Girls

Boys

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