E-cigarettes are an alternative to traditional cigarettes, and although they have less nicotine and tar compared to traditional cigarettes, they still have harmful substances, such as nicotine, so it is not recommended for men to smoke e-cigarettes during pregnancy preparation. There are many harmful substances in e-cigarettes, such as nicotine, heavy metals, aldehydes and ethylene glycol, which may damage men’s health and affect sperm viability and sperm quality, and reduce the ability of eggs to be fertilized, so the possibility of conception is reduced. In addition, although conception may be successful, the high rate of sperm malformation may also lead to congenital abnormalities in the development of fertilized eggs, thus causing embryonic abortion or miscarriage, so it is not recommended for men to smoke e-cigarettes during pregnancy preparation. In addition to not smoking e-cigarettes, men should not drink alcohol, be exposed to radiation or toxic substances, or take drugs that affect sperm quality and activity to prevent sperm levels from being affected, and they should get enough sleep, have a healthy state of mind, and exercise regularly to improve their physical fitness. If you mistakenly smoke e-cigarettes or once in a while, there is usually no serious effect, and you can promote the metabolism of harmful substances by drinking more water and eating more fresh fruits and vegetables.