Marginally low birthweight increases the risk of underweight and short stature at three and a half years of age.

AIM: Little is known about the long-term health of marginally low birthweight (LBW) children. This study characterised growth among infants weighing 2000 g-2500 g and explored the prevalence and predictors of sustained growth restriction.

METHOD: This prospective observational trial followed the weight and height of 281 Swedish marginally LBW children from birth to 3.5 years of age. Children with a standard deviation score (SDS) for body mass index or height below -2 were considered underweight and short, respectively.

RESULTS

The mean SDS for weight and height showed a rapid increase before 12-19 weeks of age. The most rapid weight gain was in infants born small for gestational age. However, at 3.5 years of age, 9.5% of the children remained underweight and 6.5% had short stature. Regression models showed that slow weight gain before 19 weeks of age was the strongest predictor for lasting underweight, while slow height gain before 19 weeks of age and male sex were associated with short stature.

CONCLUSION

Marginally LBW infants were more likely to be underweight and have a short stature at 3.5 years of age and the absence of catch-up growth during the first five months after birth identified those at highest risk.