Electronic cigarettes are relatively new devices. They were invented in 2003 with the aim of reducing the harm caused by cigarette smoking. Since their debut, they have achieved worldwide popularity, which continues to grow. The public believes that e-cigarettes are harmless or only slightly harmful. This leads to dangerous trends - increased use of e- cigarettes by young people and pregnant women. Indeed, e-cigarette aerosol contains much lower concentrations of toxic and carcinogenic substances compared to traditional cigarettes. Furthermore, e-cigarettes are a much safer option for most adults. However, this does not mean that they are entirely safe - particularly for a group such as pregnant women. Electronic cigarettes deliver the same or even higher concentrations of nicotine as traditional cigarettes. However, the placental barrier is no obstacle to nicotine. There are many reports of its harmfulness to fetal development. Nicotine impairs the development of the respiratory, nervous, and cardiovascular systems, among others. In addition, the aerosol of electronic cigarettes has a significant number of additives, which are highly dependent on the manufacturer. As a result, we are unable to know all their side effects. Furthermore, despite reports of the harmfulness of e-cigarettes, it is still uncertain whether they are an effective method of quitting the smoking habit. There are some works which indicate a decrease in the effectiveness of attempts to stop using cigarettes. What is more, there are also those which
demonstrate that the use of e-cigarettes can lead to dual use with traditional cigarettes. Given the current state of knowledge, pregnant women should not be advised to use e-cigarettes to stop smoking traditional ones. Certainly, the use of e-cigarettes during pregnancy should be strongly discouraged.