According to the "China Smoking Health Hazard Report 2020", the total number of smokers in China is estimated to be 350 million, of which 180 million are already addicted. In addition, more than 700 million nonsmokers are exposed to secondhand smoke and become passive smoking victims, among which the family is one of the main places of secondhand smoke exposure, and mothers and children are the most affected group.

Passive smoking is a risk factor for spontaneous abortion in pregnant women and an important risk factor for the occurrence of gestational hypertension syndrome and pregnancy complications, and it also affects embryonic development with adverse pregnancy outcomes such as miscarriage, stillbirth, intrauterine growth retardation, preterm birth, immune deficiency, birth defects, and mental retardation.

Helping smokers quit is the fundamental solution to reducing secondhand smoke exposure. The accessibility and effectiveness of traditional offline smoking cessation intervention services do not meet the needs of society. With the development of mobile communication technology, digital cessation such as SMS cessation, WeChat cessation, and APP cessation have emerged, which combine clinical cessation guidelines with software technology and present rich product features and interactive design, providing a new solution to expand the accessibility of clinical cessation interventions and address the problem of secondhand smoke exposure.We hope to explore the impact of different digital cessation tools and their combinations on reducing smoking prevalence and maternal tobacco exposure.

This project is a two-arm, practical-utility randomized controlled trial.The study was designed to enroll 2214 quitters, and maternal cessation of enrollment after completion of the quitter enrollment.After self-reported exposure to secondhand smoke has been tested with a free cotinine urine test and the pregnant woman has signed an informed consent, she invites the smoker who is causing her secondhand smoke to quit, which may include her husband, family, friends, colleagues, neighbors, etc., or the pregnant woman herself.

Invited smokers will choose a quit day within two weeks of enrollment, use a cognitive behavioral therapy-based cessation package and online coaching from medical staff, as well as additional digital cessation tools, and receive a 12-week follow-up (smoking/quit status). Enrolled pregnant women will receive general education on maternal and child health management and the dangers of tobacco, and will be encouraged to provide psychological support and encouragement to invited quitters in the mini-program (provided both parties volunteer). The pregnant women will receive a 16-week follow-up (secondhand smoke exposure).

At the end of the study, all pregnant women and those who self-report successful cessation will receive a free cotinine test as an objective test of cessation effectiveness.

Inclusion Criteria:

1. Pregnant women's inclusion criteria A. Adult females during gestation and within 42 days after delivery B. I do not smoke, but I self-reported secondhand smoke exposure problems
2. Inclusion criteria for smoking quitters A. Adults over the age of 18 who smoke every day; B. I have a clear intention to quit smoking;

Exclusion Criteria:

1. Maternal maternal exclusion criteria A. I am a smoker (pregnant women who are willing to quit smoking can join the smoking cessation group) B. Self-report had no risk of secondhand smoke exposure
2. Exclusion criteria for smoking quitters A. Receiving other smoking cessation interventions; B. having a severe mental illness or psychological disorder C. No smart phone or not skilled to use WeChat mini program