Meyer M B, Tonascia J A, Buck C
Am J Epidemiol. 1974 Dec;100(6):443-52. doi: 10.1093/oxfordjournals.aje.a112056.
Increased perinatal mortality among smokers' babies has been observed in many but not in all studies, with a statistically significant difference in some. This paper explores the hypothesis that maternal smoking may interact with other risk factors, so that a dose-related increase in perinatal mortality may be enhance or masked depending upon the presence or absence of these factors. Data are from the Ontario Perinatal Mortality Study of all single b irths in 10 teaching hospitals in Ontario in 1960-1961 a total of 51,490 births, including 701 fetal deaths and 655 early neonatal deaths. Perinatal mortality increased significantly with smoking, and was also affected by such factors as maternal age, parity, hospital status, previous pregnancy history, hemoglobin level, and others. Smoking frequencies also varied by many of these characteristics. Perinatal mortality was therefore analyzed by the amount smoked during pregnancy within subgroups of these antecedent risk factors. When smoking and other risk factors were cross-tabulated among 52 data subgroups, only the light smokers (less than 1 pack per day) under age 20 had lower perinatal mortality rates than their nonsmoking counterparts. In almost all subgroups the mortality increase with smoking was dose-related, but not in a simple, linear way. The increased risk of perinatal mortality associated with light smoking among young, low-parity, non-anemic mothers was less than 10 percent. At the other extreme, mothers of high parity, public hospital status, with previous low birthweight births, or with hemoglobin less than 11 gm had increased perinatal mortality risks of 70-100 percent when they were heavy smokers. The failure of some studies to find a significant increase in perinatal mortality with maternal smoking may be due to selection of study populations from the end of the spectrum where light smoking is associated with only a slight increase in perinatal risk. Other studies may select higher risk populations, where the influence of smoking on mortality is stronger. Depending on the magnitude of the difference, the amount smoked, and the size of the study, results might or might not be statistically significant.
许多研究观察到吸烟孕妇的婴儿围产期死亡率上升，但并非所有研究均如此，部分研究中存在统计学上的显著差异。本文探讨一种假说，即母亲吸烟可能与其他风险因素相互作用，从而根据这些因素的存在与否，与剂量相关的围产期死亡率增加可能会增强或被掩盖。数据来自安大略省围产期死亡率研究，该研究涵盖了1960 - 1961年安大略省10家教学医院的所有单胎分娩，共计51,490例分娩，包括701例胎儿死亡和655例早期新生儿死亡。围产期死亡率随吸烟显著增加，并且还受到母亲年龄、产次、医院状况、既往妊娠史、血红蛋白水平等因素的影响。吸烟频率也因这些特征中的许多因素而有所不同。因此，在这些先行风险因素的亚组中，根据孕期吸烟量对围产期死亡率进行了分析。当在52个数据亚组中对吸烟与其他风险因素进行交叉制表时，只有年龄在20岁以下的轻度吸烟者（每天少于1包）的围产期死亡率低于不吸烟的同龄人。在几乎所有亚组中，吸烟导致的死亡率增加与剂量相关，但并非以简单的线性方式。年轻、低产次、非贫血母亲中，轻度吸烟导致的围产期死亡风险增加不到10%。在另一个极端情况下，高产次、公立医院分娩、既往有低体重儿出生或血红蛋白低于11克的母亲，在重度吸烟时围产期死亡风险增加70 - 100%。一些研究未能发现母亲吸烟导致围产期死亡率显著增加，可能是由于从范围末端选择研究人群，在该范围内轻度吸烟仅与围产期风险略有增加相关。其他研究可能选择了风险较高的人群，在这些人群中吸烟对死亡率的影响更强。根据差异的大小、吸烟量和研究规模，结果可能具有或不具有统计学显著性。
