This study aimed to examine the relationship between age at first childbirth and oral health. The mediation effect of body mass index (BMI) on this relationship was also determined.
This study analyzed data of 2,506 parous postmenopausal women aged 50 or older from the Korea National Health and Nutrition Examination Survey 2013-2015. Chewing inconvenience was investigated by an oral interview. Periodontitis and dental caries were determined through dental examinations. Multivariable logistic regression analysis was performed to examine the relationship between age at first childbirth and oral health, and mediation analysis was performed to examine the contribution of BMI on the relationship between age at first childbirth and oral health.
Women who underwent their first delivery between the age of 26 and 46 years had significantly decreased odds of chewing inconvenience (odds ratio [OR] = 0.72, 95% confidence interval [95% CI] = 0.56-0.93, P = 0.010) compared with the odds of those women whose first delivery was between at the age of 15 and 22 years. We also found a significant linear relationships between age at first childbirth and odds of chewing inconvenience (OR = 0.83, 95% CI = 0.74-0.95, P = 0.017) and dental caries (OR = 0.84, 95% CI = 0.74-0.96, P = 0.025). BMI accounted for 12.9% of the relationship between age at first childbirth and dental caries. Age at first childbirth was only indirectly associated with periodontitis through BMI (OR = 0.98, 95% CI = 0.96-0.99, P = 0.003).
Women whose first delivery occurred at a young age had significantly increased odds of chewing inconvenience and dental caries. BMI mediated the relationships between age at first childbirth and periodontitis and dental caries.