Obstetrics, Sao Lucas Hospital da Pontificia Universidade Catolica do Rio Grande do Sul, Rio Grande do Sul, Porto Alegre, Brazil.
BMC Pregnancy Childbirth. 2011 Mar 31;11:24. doi: 10.1186/1471-2393-11-24.
Despite the existence of various published studies regarding the effects of tobacco smoking on pregnancy, and especially in regards to placental blood flow and vascular resistance, some points still require clarification. In addition, the amount of damage due to tobacco smoking exposure that occurs has not been quantified by objective means. In this study, we looked for a possible association between flow resistance indices of several arteries and the levels of urinary cotinine and the concentration of carbon monoxide in the exhaled air (COex) of both smoking and non-smoking pregnant women. We also looked for a relationship between those findings and fetal growth and birth weight.
In a prospective design, thirty pregnant smokers and thirty-four pregnant non-smokers were studied. The volunteers signed consent forms, completed a self-applied questionnaire and were subjected to Doppler velocimetry. Tobacco smoking exposure was quantified by subject provided information and confirmed by the measurement of urinary cotinine levels and by the concentration of carbon monoxide in the exhaled air (COex). The weight of newborns was evaluated immediately after birth.
Comparing smoking to non-smoking pregnant women, a significant increase in the resistance index was observed in the uterine arteries (P = 0.001) and umbilical artery (P = 0.001), and a decrease in the middle cerebral artery (P = 0.450). These findings were associated with progressively higher concentrations of COex and urinary cotinine. A decrease in the birth weight was also detected (P < 0.001) in association with a progressive increase in the tobacco exposure of the pregnant woman.
In pregnant women who smoke, higher arterial resistance indices and lower birth weights were observed, and these findings were associated with increasing levels of tobacco smoking exposure. The values were significantly different when compared to those found in non-smoking pregnant women. This study contributes to the findings that smoking damage during pregnancy is dose-dependent, as demonstrated by the objective methods for measuring tobacco smoking exposure.
尽管已经有许多关于吸烟对妊娠影响的研究发表，尤其是关于胎盘血流和血管阻力方面，但仍有一些方面需要进一步阐明。此外，吸烟暴露造成的损害程度尚未通过客观手段进行量化。在这项研究中，我们试图寻找吸烟孕妇和非吸烟孕妇的几条动脉的血流阻力指数与尿可替宁水平和呼气中一氧化碳浓度（COex）之间的可能关联，同时也关注这些发现与胎儿生长和出生体重的关系。
采用前瞻性设计，研究了 30 名吸烟孕妇和 34 名非吸烟孕妇。志愿者签署了知情同意书，完成了一份自我应用的问卷，并接受了多普勒流速测定。吸烟暴露量通过志愿者提供的信息进行量化，并通过尿可替宁水平和呼气中一氧化碳浓度（COex）的测量进行验证。新生儿体重在出生后立即进行评估。
与非吸烟孕妇相比，吸烟孕妇的子宫动脉（P=0.001）和脐动脉（P=0.001）的阻力指数显著增加，而大脑中动脉（P=0.450）的阻力指数降低。这些发现与 COex 和尿可替宁浓度的逐渐升高有关。还检测到出生体重下降（P<0.001），与孕妇吸烟暴露量的逐渐增加有关。
在吸烟的孕妇中，观察到较高的动脉阻力指数和较低的出生体重，并且这些发现与吸烟暴露量的增加有关。与非吸烟孕妇相比，这些值有显著差异。这项研究证实了吸烟对妊娠的损害是剂量依赖性的，这是通过客观的吸烟暴露测量方法来证明的。
