THE ESSENTIAL
- Between 20 and 25% of pregnant women smoke, according to the 2017 France Public Health Barometer. This smoking is more common among young and less educated women.
- During pregnancy, it is recommended not to smoke or be exposed to other people’s smoke, as tobacco harms the development of the fetus.
- This study shows that the majority of smokers reduce their tobacco consumption even before becoming aware of the pregnancy.
Pregnancy is usually a period that pushes smokers to reduce their cigarette consumption. But if, beyond any desire to preserve his child, there would also be a biological mechanism behind this approach? This is shown by researchers from Northwestern Medicine in the United States. The study was published in the journal Addiction Biologyon October 17th.
1 less cigarette a day before becoming aware of their pregnancy
Much research has focused on the impact of smoking during pregnancy on the baby, but the question of how pregnancy influences the smoking behavior of the mother has never been studied.
“APrior to this article, it was largely assumed that the only thing driving pregnant smokers to cut back was a desire to protect the baby.”, said the author and the study’s lead researcher, Dr. Suena Huang Massey, a psychiatrist and associate professor of psychiatry and behavioral and medical social sciences at Northwestern University Feinberg School of Medicine in Chicago. “Although our study supports the finding of pregnancy as a salient event, smoking levels during pregnancy began to decline before smokers suspected they were pregnant.”
The scientists studied two separate cohorts comprising 416 participants. These women smoked an average of half a pack of cigarettes a day the month before conception. According to the results, pregnant smokers smoked one less cigarette a day, even before they knew they were expecting a child. Once aware of their pregnancy, they reduced their consumption by an average of four additional cigarettes daily.
hCG: do pregnancy hormones reduce the urge to smoke?
“Strikingly, we observed the greatest declines in smoking precisely when hCG levels typically peak, between five and 10 weeks into pregnancy.”, explained the researcher. hCG, or Chorionic Gonadotropin hormone, is secreted by the placenta at the very beginning of pregnancy, and its level then increases steadily throughout the first trimester. It is this hormone that is partly responsible for nausea in the first few months.
“Additionally, pregnant women who do not quit during the first trimester (when hCG levels are high) are unlikely to quit before childbirth, even with the help of medication or financial incentives.”, clarified Dr. Massey. According to the specialist, the precise identification of these processes could lead “the development of new drugs to stop smoking”.