Prognostic factors for normal postnatal growth rate in low birth weight infants

Abstract

Postnatal growth restriction in low birth weight infants is associated with long term adverse
neuro-developmental sequel. Meanwhile, infants with excessive weight gain in early weeks of
life have a greater likelihood of later obesity, cardiovascular disease, and diabetes. Identifying
factors associated with acceptable growth rate in low birth weight infants is important to
prevent this potential long term morbidity. The aim of this study was to identify factors associated
with acceptable growth rate in low birth weight infants. Prospective cohort study was conducted
among 73 low birth weight infants. Growth rate of these infants was determined by serial
weight measurement during perinatal care and after being discharged until 46 – 50 weeks post
menstrual age. Growth rate was considered normal if average daily weight gain is 10 – 20 g/kg/
day. Factors associated with this acceptable growth rate were analyzed by univariate and
multivariate statistical analysis. Normal growth rate was found in 62.7% subjects (42/67).
Significant rate difference of average daily growth was found between small for gestational age
(SGA) infants and appropriate for gestational age (AGA) infants (mean difference -2.90 g/kg/
day; 95%CI: -5.68 - -0.12). The SGA infants had a greater risk for gaining weight below acceptable
growth rate (adjusted RR= 2.9; 95%CI: 1.1 – 8.5). In conclusion, SGA is the only factor which
can be associated with normal growth rate in low birth weight infants. Moreover, SGA infants
are in a greater risk for having slower growth rate compared to AGA.

Keywords: growth rate - post natal - low birth weight – prognostic - gestational rate