Growth and Bone Mineralization in Preterm Infants Fed Preterm Formula or Standard Term Formula after Discharge

Objective

To evaluate growth and bone mineralization in very low birth weight (VLBW) infants fed preterm formula (PF) or term formula (TF).

Study design

In a double-blind prospective study, 49 preterm infants of gestational age 33 weeks or less were randomly fed PF or TF for 2 months after discharge, then all of the infants were fed TF for the next 2 months. Anthropometric and dual-energy x-ray absorptiometry data were collected at discharge and at 2 months and 4 months after discharge. Anthropometric data also were collected at 12 months postterm.

Results

Four months after discharge, both body weight (6139 ± 1254 g vs 5540 ± 863 g; P = .03) and bone mineral content (104.4 ± 29.2 g vs 87.5 ± 17.1 g; P = .01) were significantly higher in the PF group compared with the TF group. At 12 months postterm, mean body weight, length, and head circumference remained higher in the PF group than in the TF group, and body mass index was similar and within the normal range in the 2 groups.

Conclusions

At 4 months after discharge, growth and mineralization were better in the VLBW infants who were fed PF during the first 2 months after discharge compared with those who were fed TF, suggesting that PF may be particularly valuable at this early stage of development.

Abbreviations: BA, Bone area, BMC, Bone mineral content, BMD, Bone mineral density, DEXA, Dual-energy X-ray absorptiometry, PDF, Postdischarge formula, PF, Preterm formula, SD, Standard deviation, SDS, Standard deviation score, SGA, Small for gestational age, TF, Term formula, VLBW, Very low birth weight