Nilsen S T, Sagen N, Kim H C, Bergsjø P
Am J Obstet Gynecol. 1984 Mar 15;148(6):752-8. doi: 10.1016/0002-9378(84)90561-1.
Of 811 otherwise healthy, nonanemic, pregnant Norwegian women, 43% smoked during the third trimester. No significant association existed between smoking habits and hemoglobin levels during the third trimester, but the fairly small number of heavy smokers (greater than 10 cigarettes per day) may have precluded the discovery of subtle true differences. Birth weights were transferred to a weight-for-dates percentile scale, based on the distribution of the total Norwegian birth population over an 11-year period. With a grouping in quartiles according to this scale, a strong correlation between smoking habits and low birth weights emerged, with 47% of newborn infants of heavy smokers falling in the lowest quartile. Levels of hemoglobin were inversely correlated to birth weight quartiles, equally in mothers who smoked and those who did not smoke. However, when birth weights were grouped according to maternal hemoglobin at term, the tobacco-related effect on birth weight appeared only with levels of hemoglobin above 12 gm/dl, being particularly strong for levels above 13 gm/dl. Hemoglobin levels of 9.0 to 11.9 gm/dl appeared to protect from growth retardation the fetuses of nonanemic mothers who smoked. Studying ponderal, or weight-by-length, indices, we found that growth-retarded babies of mothers who smoked tended to be thin, thus indicating that they had been deprived of nutrients.
在811名身体健康、无贫血症状的挪威孕妇中，43%的人在孕晚期吸烟。吸烟习惯与孕晚期血红蛋白水平之间不存在显著关联，但重度吸烟者（每天超过10支烟）数量相对较少，可能妨碍了对细微真实差异的发现。根据挪威11年期间出生人口总数的分布情况，将出生体重换算为孕周体重百分位数。按照此标准将孕妇分为四分位数组后，吸烟习惯与低出生体重之间呈现出强烈的相关性，重度吸烟者中有47%的新生儿处于最低四分位数组。血红蛋白水平与出生体重四分位数呈负相关，吸烟和不吸烟的母亲情况均如此。然而，当根据足月时母亲的血红蛋白水平对出生体重进行分组时，烟草对出生体重的影响仅在血红蛋白水平高于12克/分升时出现，在高于13克/分升时尤为明显。血红蛋白水平在9.0至11.9克/分升之间似乎能保护吸烟的非贫血母亲的胎儿免于生长迟缓。通过研究 ponderal指数（即体重与身长之比），我们发现吸烟母亲所生的生长迟缓婴儿往往偏瘦，这表明他们缺乏营养。
