Association between age at first childbirth and type 2 diabetes in Chinese women

The present study aims to explore the relationship between age at first childbirth and developing type 2 diabetes, and analyze potential modifiers of its relationship.

The data were obtained from the baseline survey of a large-scale cohort study in 10 diverse areas of China. Multivariate logistic regressions were used to analyze the association between developing type 2 diabetes and the age at first childbirth. Adjustments were made in each model on sociodemographic, socioeconomic and reproductive covariates. Subgroup analyses were further carried out to investigate the effects of reproductive factors, body mass index at 25 years of age and hypertension on the above-mentioned association.

Women who have their first child at age <20 years (odds ratio [OR] 1.33, 95% confidence interval [CI] 1.22-1.44) and between the ages of 20 and 24 years (OR 1.16, 95% CI 1.10-1.23) were more likely to be diagnosed with type 2 diabetes compared with those who have their first child between the ages of 25 and 29 years; equal to or more than three parities (OR 1.44, 95% CI 1.30-1.60), premenopausal status (OR 1.58, 95% CI 0.99-2.54), overweight at age 25 years (OR 1.62, 95% CI 1.37-1.93) and hypertension (OR 1.37, 95% CI 1.22-1.53) are all conditions found to increase the odds of developing type 2 diabetes in those who have their their first child at an early age (<20 years).

The study concluded that having the first child at an early age is associated with an increased likelihood of developing type 2 diabetes later in life; reproductive factors, overweight at age 25 years and status of hypotension could modify such an association.