Longitudinal study of the evolution (from birth to 8 years of age) of anthropometric variables in a cohort of very low birth weight infants

Objective: Descriptive anthropometric survey in a cohort of very low birth weight infants (VLBWI) newborns from birth to age 8 years, analyzing the growth characteristics in these patients.

Methods: Retrospective registration of weight and height at birth and age 0.5, 1, 1.5, 2, 3, 4, 6 and 8 years in a cohort of 170 VLBWI (< 1500 g). Patients were separated into appropriate for gestational age (AGA, n=101) and low birth weight or small for gestational age (SGA, n=69) according to the charts from Carrascosa et al. Anthropometric variables were compared with those from a control group.

Results: Gestational age was 30.4±3.1 weeks. Weight and height at birth were 1182.1± 228.4 g and 38.2± 3.2 cm, respectively. Weight, height and body mass index in both sexes and every considered age were higher (p<0.05) within the control group with respect to VLBWI (AGA and SGA). At age 2, 81.2% and 71% of AGA and SGA (p<0.05) respectively, presented with normal height. At age 8, the height of 8.95% of AGA and 17.4% of SGA infants did not exceed the 2 SD below the average of the control group.

Conclusions: VLBWI have a catch-up growth which allows the acquisition of normal height in 87.1% and 78.3% of patients in groups AGA and SGA, respectively, at age 4. Only 8.9% of patients in group AGA did not present catch-up growth at age 8, being the possibility of treatment with growing hormone (GH) not included.