Maternal smoking during pregnancy (MSDP) is associated with lower birth weight, childhood obesity, and elevated blood pressure (BP) in offspring. We aimed to examine whether birth weight and body mass index (BMI) mediate the effect of MSDP on BP in children. The study included 14,713 children aged 8 to 15 years from the National Health and Nutrition Examination Surveys from 1999 to 2018. General third-variable models were used to examine the mediating effects of birth weight and BMI on the association of MSDP with BP. A total of 1928 (13.1%) children were exposed to MSDP. MSDP was associated with reduced birth weight (p < 0.001), increased BMI (p < 0.001), and elevated systolic BP (p = 0.005). MSDP was not associated with systolic BP after adjustment for birth weight and BMI z-score (p = 0.875), with 95.0% of the effect of MSDP on BP mediated by birth weight (39.1%) and BMI (55.9%). In conclusion, lower birth weight and increased obesity measures mediate the adverse effects of MSDP on BP in children. These findings provide novel mechanistic insight into the adverse effect of MSDP on BP in children and have implications for preventing hypertension in later life.

母亲怀孕期间吸烟 (MSDP) 与后代出生体重降低、儿童肥胖和血压升高 (BP) 相关。我们的目的是研究出生体重和体重指数 (BMI) 是否介导 MSDP 对儿童血压的影响。该研究纳入了 1999 年至 2018 年全国健康和营养检查调查中的 14,713 名 8 至 15 岁儿童。采用一般第三变量模型来检验出生体重和 BMI 对 MSDP 与血压关联的中介作用。共有 1928 名 (13.1%) 儿童接触过 MSDP。MSDP 与出生体重减轻 ( p  < 0.001)、BMI 增加 ( p  < 0.001) 和收缩压升高 ( p  = 0.005) 相关。调整出生体重和 BMI z 分数后，MSDP 与收缩压无关（p  = 0.875），MSDP 对血压的影响 95.0% 由出生体重 (39.1%) 和 BMI (55.9%) 介导。总之，较低的出生体重和增加的肥胖措施介导了 MSDP 对儿童血压的不利影响。这些发现为 MSDP 对儿童血压的不利影响提供了新的机制见解，并对以后生活中预防高血压具有重要意义。