E-cigarette usage may impair fertility and pregnancy outcomes, according to a mouse study published in the Journal of the Endocrine Society.
Researchers led by Kathleen Caron, PhD, of University of North Carolina at Chapel Hill, N.C., point out that while the dangers of cigarette smoke are well established, the England Public Health system has ruled e-cigarettes to be 95% safer than conventional cigarettes and subsequently, the public is encouraged to use e-cigarettes as an effective smoking cessation tool. “Contrastingly, the European Respiratory Society reported that the safety of extended use of e-cigarettes compared with conventional tobacco is unknown,” the authors write. “Thus, studies of the safety of e-cigarettes are needed, especially among pregnant women and future offspring.”
Caron and her team write that recent literature shows that e-cigarette exposure in utero causes changes in metabolic, inflammatory, neurologic, and pulmonary factors in exposed mouse offspring. “However, the reproductive fitness and fetal outcomes of dams exposed to e-cigarettes before and during pregnancy have yet to be determined,” the authors write. “Here, we directly examine the effects of e-cigarettes on pregnancy initiation and second-generation fetal reproductive health and find that e-cigarettes delay implantation and impair the health of future offspring.”
In this study, researchers used a mouse model to examine whether e-cigarette exposure impairs fertility and offspring health. After exposure to e-cigarette vapor, female mice showed decreased embryo implantation and a significant delay in the onset of pregnancy with the first litter. Female offspring exposed to e-cigarettes in utero also failed to gain as much weight as control mice by the 8.5 month mark.
The researchers write that e-cigarettes are being used more and more by reproductive-age and even pregnant women, so it is important to evaluate whether and how e-cigarettes contribute to pregnancy success and fetal health. They go on to write that further clinical investigations are needed to examine how e-cigarettes may affect pregnancy initiation in women. Based on the results of this study, the authors write that “e-cigarettes negatively influence implantation success and the future health of the in utero exposed fetus, resulting in abnormal pregnancy outcomes.”
“We found that e-cigarette usage prior to conception significantly delayed implantation of a fertilized embryo to the uterus, thus delaying and reducing fertility (in mice),” Caron says. “We also discovered that e-cigarette usage throughout pregnancy changed the long-term health and metabolism of female offspring—imparting lifelong, second-generation effects on the growing fetus. These findings are important because they change our views on the perceived safety of e-cigarettes as alternatives to traditional cigarettes before and during pregnancy.”