The association between birth weight and proxy-reported health-related quality of life among children aged 5 − 10 years old: A linked data analysis

Background Birth weight has a substantial effect on children’s cognitive development, physical capability, and emotional development, which in turn impact on Health-Related Quality of Life (HRQoL). Generally, evidence indicates that children born with low birth weight tend to have poorer proxy-reported HRQoL, particularly at school age. However, there is limited evidence on whether variation in HRQoL exists across the entire range of possible birth weights. This study aimed to examine the association between birth weight and proxy-reported HRQoL among children aged 5–10 years old. Methods Data from the 1973–78 cohort of the Australian Longitudinal Study on Women’s Health were linked with state-based Perinatal Data Collections and the Mothers and their Children’s Health study for 1,589 mothers and 2,092 children aged 5 − 10 years old. Generalized estimating equations were used to model the association between birth weight and proxy-reported HRQoL measured by the Pediatric Quality of Life Inventory 4.0. Results are presented as odds ratios with 95 % confidence intervals. Results In this study, 15.61 % of children were at risk of impaired proxy-reported HRQoL. Each 100-gram increase in birth weight was associated with a 3 % reduction in the odds of impaired HRQoL (AOR = 0.97; 95 % CI: 0.94, 0.99). However, there was only limited evidence of an effect within the normal birth weight range (AOR = 0.97; 95 % CI: 0.94, 1.01). Conclusions The findings indicate that increased birth weight was protective against impaired HRQoL, although there was limited evidence of variability within the normal birth weight range. This study contributes to the existing literature by not only emphasizing the impact of low birth weight on children’s health and health-related outcomes but also by focusing on the variability within the normal birth weight range, particularly in a setting where low birth weight is less prevalent.