Everson R B
Lancet. 1980 Jul 19;2(8186):123-7. doi: 10.1016/s0140-6736(80)90007-0.
Studies which provide evidence suggesting that cancer could result from transplacental exposure to maternal smoking include animal experiments showing that: (1) compounds present in tobacco smoke and cigarette smoke condensate itself are active transplacental carcinogens; (2) the fetus has greater sensitivity to some carcinogens than the adult, so that estimates of doses necessary for transplacental carcinogenesis cannot be accurately predicted from effects in adults; (3) carcinogens administered transplacentally can increase sensitivity to later carcinogenic exposures; and (4) many (at lower doses probably most) tumours resulting from transplacental exposure are not evident until adulthood and their morphology and sites do not differ from those of spontaneously occurring tumours. Studies in man have shown that components of tobacco smoke can reach the fetus and that human fetal tissues are capable of activating carcinogens similar to those in tobacco smoke. These findings suggest that conditions causing transplacental carcinogenesis in animals may be duplicated in man by prenatal exposure to maternal smoking, and that resulting tumours could occur in adulthood. In view of the widespread prevalence of smoking during pregnancy, epidemiological studies of cancer in adults should investigate the possible role played by maternal smoking in increasing cancer risk.
一些研究提供的证据表明，经胎盘接触母亲吸烟可能会导致癌症，这些研究包括动物实验，实验显示：（1）烟草烟雾和香烟烟雾冷凝物中的化合物本身就是活性经胎盘致癌物；（2）胎儿对某些致癌物的敏感性高于成年人，因此不能根据对成年人的影响准确预测经胎盘致癌所需的剂量；（3）经胎盘给予的致癌物会增加对后来致癌暴露的敏感性；（4）许多（可能大多数在较低剂量下）经胎盘接触导致的肿瘤直到成年才显现出来，其形态和部位与自发产生的肿瘤并无不同。对人类的研究表明，烟草烟雾的成分可以到达胎儿体内，并且人类胎儿组织能够激活与烟草烟雾中类似的致癌物。这些发现表明，动物中导致经胎盘致癌的情况可能会因产前接触母亲吸烟而在人类中重现，并且由此产生的肿瘤可能在成年期出现。鉴于孕期吸烟的普遍存在，对成年人癌症的流行病学研究应该调查母亲吸烟在增加癌症风险中可能扮演的角色。
