Macrosomic Neonates Carry Increased Risk of Dental Caries in Early Childhood: Findings from a Cohort Study, the Okinawa Child Health Study, Japan.

Background: Although many studies have discussed health risks in neonates with a low birth weight, few studies have focused on the risks in neonates with a high birth weight. The objective of this study was to determine whether differences in the incidence of dental caries in early childhood are associated with birth weight status.

Methods: A total of 117,175 children born in Okinawa Prefecture, Japan from 1997 to 2007 were included in this study. Medical professionals collected information about birth records, growth and development, parental child-rearing practices and dental health at 3 months, 18 months and 3 years of age. The risk of dental caries among neonates with macrosomia (birth weight ≥4000 g) was compared with that among neonates with normal weight (2500-3999 g). Sensitivity analyses included 'large for gestational age' (LGA, birth weight above the 90th percentile for gestational age), which was relative to 'appropriate for gestational age' (birth weight between 10th and 90th percentiles). Relative risks and relative risk increases were estimated by multivariate Poisson regression.

Results: At 3 years of age, the relative risk increases for dental caries after adjusting for confounding factors were 19% [95% confidence interval (CI), 11%-28%, P < 0.001] for macrosomic neonates and 12% (95% CI, 9%-16%, P < 0.001) for LGA neonates.

Conclusion: Macrosomia and LGA were associated with an increased risk of dental caries in early childhood. Particular attention should be paid to abnormally large neonates.