Gennser G, Marsál K, Brantmark B
Am J Obstet Gynecol. 1975 Dec 15;123(8):861-7. doi: 10.1016/0002-9378(75)90863-7.
Pregnant, habitually smoking women were studied during the last trimester when smoking a standard cigarette, smoking a nontobacco cigarette, or chewing a piece of chewing gum containing 2 or 4 mg. of nicotine. The effects of the experimental interventions were followed on the concentration of nicotine and the percentage of carboxyhemoglobin (COHb) in maternal blood, on the amount and pattern of the fetal breathing movements, and on the maternal heart rate, breathing rate, and blood glucose level. The maternal blood concentration of nicotine was increased by the standard cigarette, the 4 mg. nicotine chewing gum, and the 2 mg. nicotine chewing gum in descending order. The COHb percentage in maternal blood was increased by the standard cigarette and to a lower degree by the nontobacco cigarette. A significant increase of apnea and periodic breathing movements in the fetus followed the smoking of a standard cigarette; a similar but nonsignificant change occurred in a dose-related way after the 4 mg. and the 2 mg. chewing gum. The maternal heart rate was positively correlated to the level of blood breathing movements occurring after smoking one standard cigarette. The suppression of the fetal breathing movements in utero poses the question whether iterated maternal smoking might influence the prenatal assessment of fetal maturity using determination of pulmonary surfactants in the amniotic fluid.
对怀孕且有吸烟习惯的女性在妊娠晚期进行了研究，她们分别吸标准香烟、吸不含烟草的香烟或咀嚼含有2毫克或4毫克尼古丁的口香糖。跟踪实验干预措施对母体血液中尼古丁浓度、碳氧血红蛋白（COHb）百分比、胎儿呼吸运动的数量和模式以及母体心率、呼吸频率和血糖水平的影响。母体血液中尼古丁浓度因吸标准香烟、4毫克尼古丁口香糖和2毫克尼古丁口香糖而依次升高。母体血液中的COHb百分比因吸标准香烟而升高，吸不含烟草的香烟则使其升高程度较低。吸标准香烟后胎儿呼吸暂停和周期性呼吸运动显著增加；4毫克和2毫克口香糖后也出现了类似但不显著的剂量相关变化。母体心率与吸一支标准香烟后出现的呼吸运动水平呈正相关。子宫内胎儿呼吸运动的抑制引发了一个问题，即母亲反复吸烟是否会影响通过测定羊水肺表面活性物质来对胎儿成熟度进行的产前评估。
