Fox S H, Koepsell T D, Daling J R
Department of Epidemiology, University of Washington School of Public Health and Community Medicine, Seattle.
Am J Epidemiol. 1994 May 15;139(10):1008-15. doi: 10.1093/oxfordjournals.aje.a116940.
Cigarette smoking during pregnancy is an important, avoidable factor associated with low birth weight. Maternal age is also associated with variations in birth weight. Using birth certificate data from all 347,650 singleton births for which maternal age and birth weight were recorded during 1984-1988 in Washington State, this study investigated birth weight and smoking during pregnancy (yes/no) for mothers of different ages. In multiple linear regressions adjusted for race, marital status, parity, adequacy of prenatal care, and urban/rural residence, the decrement in mean birth weight associated with smoking grew steadily from 117 g for the youngest mothers (age less than 16 years) to 376 g for the oldest (age 40 years or more). Similarly, the adjusted relative risk of having a low weight birth (less than 2,500 g) for smokers compared with nonsmokers was lowest for mothers aged 16-17 years, at 1.43 (95% confidence interval 1.22-1.68), and increased steadily to 2.63 (95% confidence interval 1.77-3.90) for mothers aged 40 or more. This result suggests that the effect of exposure to cigarette smoking during pregnancy is modified by advancing maternal age. Further research using data that more precisely measure the exposure (cigarettes per day, years smoked) could help further clarify this issue and better address the public health question of whether smoking cessation programs ought to focus limited resources more selectively toward pregnant smokers in particular age groups.
孕期吸烟是导致低出生体重的一个重要且可避免的因素。母亲年龄也与出生体重的变化有关。本研究利用华盛顿州1984 - 1988年期间记录了母亲年龄和出生体重的347,650例单胎分娩的出生证明数据，调查了不同年龄母亲的出生体重及孕期吸烟情况（是/否）。在对种族、婚姻状况、产次、产前护理充足程度以及城乡居住情况进行调整的多元线性回归分析中，与吸烟相关的平均出生体重下降幅度从最年轻母亲（年龄小于16岁）的117克稳步增加到最年长母亲（年龄40岁及以上）的376克。同样，吸烟者与非吸烟者相比出生体重低（小于2500克）的调整后相对风险在16 - 17岁母亲中最低，为1.43（95%置信区间1.22 - 1.68），并稳步上升至40岁及以上母亲的2.63（95%置信区间1.77 - 3.90）。这一结果表明，孕期接触吸烟的影响会随着母亲年龄的增长而改变。使用能更精确测量接触情况（每天吸烟支数、吸烟年限）的数据进行进一步研究，可能有助于进一步阐明这一问题，并更好地解决公共卫生问题，即戒烟项目是否应该将有限的资源更有针对性地集中于特定年龄组的孕妇吸烟者。
