Champix (Varenicline) Should Not Be Used During Pregnancy
Champix (varenicline) is not recommended for use during pregnancy due to insufficient evidence regarding its safety and efficacy, and behavioral counseling interventions should be the first-line approach for smoking cessation in pregnant women. 1
Guideline Recommendations
The US Preventive Services Task Force (USPSTF) provides clear guidance on this issue:
The USPSTF concludes that evidence on pharmacotherapy interventions (including varenicline) for tobacco cessation in pregnant women is insufficient because of a lack of studies, and the balance of benefits and harms cannot be determined. 1
The USPSTF identified no studies on varenicline pharmacotherapy for tobacco smoking cessation during pregnancy when evaluating interventions for pregnant persons. 1
According to FDA labeling, available studies cannot definitively establish or exclude varenicline-associated risk during pregnancy. 1
Evidence Quality and Gaps
The evidence base for varenicline in pregnancy is extremely limited:
There are no adequate, well-controlled studies of varenicline use during pregnancy in humans. 2
A 2020 French expert panel concluded that available data are very inadequate and low level of evidence to assess the impact of varenicline during pregnancy, and therefore varenicline cannot be recommended for smoking cessation during pregnancy. 2
The currently available studies are insufficient to provide evidence for the safety or efficacy of varenicline use in pregnancy. 3
There are insufficient data at this time to recommend the use of varenicline for smoking cessation during pregnancy. 4
Recommended Approach: Behavioral Interventions First
The USPSTF concludes with high certainty that the net benefit of behavioral interventions for tobacco cessation on perinatal outcomes and smoking abstinence in pregnant women who smoke is substantial. 1
Benefits of Behavioral Counseling in Pregnancy:
- Substantially improves achievement of tobacco smoking abstinence 1
- Increases infant birthweight 1
- Reduces risk for preterm birth 1
- No increase in adverse effects from psychosocial interventions 1
When Behavioral Counseling Alone Fails:
For pregnant persons for whom behavioral counseling alone does not work, clinicians are encouraged to consider the severity of tobacco dependence in each patient and engage in shared decision-making to determine the best individual treatment course. 1
Important Clinical Context
Risks of Continued Smoking During Pregnancy:
- Reduces fetal growth 1
- Increases risk of preterm birth 1
- Doubles the risk for delivering an infant with low birth weight 1
- Increases relative risk for stillbirth death by 25% to 50% 1
- Quitting smoking early in pregnancy can reduce or eliminate the adverse effects of smoking on fetal growth 1
Contrasting Evidence on Effectiveness:
While varenicline is not recommended, one 2021 observational study from Australia found that varenicline was almost three times more effective than nicotine patches in assisting pregnant women to quit smoking (33.3% vs 13.3% quit rate). 5 However, this single observational study is insufficient to overcome the lack of safety data and cannot change current guideline recommendations against its use.
Common Pitfalls to Avoid
Do not prescribe varenicline during pregnancy based on its superior efficacy in non-pregnant populations—the safety profile in pregnancy remains unknown. 1, 2
Do not assume that because a medication works well outside pregnancy, it is appropriate during pregnancy—the risk-benefit calculation fundamentally changes when considering fetal outcomes. 1
Do not withhold behavioral interventions while waiting to prescribe pharmacotherapy—behavioral counseling has proven substantial benefits with no harms. 1
FDA Drug Label Information
The FDA-approved varenicline labeling states: "Patients who are pregnant or breastfeeding or planning to become pregnant should be advised of: the risks of smoking to a pregnant mother and her developing baby, the potential risks of varenicline use during pregnancy and breastfeeding, and the benefits of smoking cessation with and without varenicline." 6
The label also advises: "Advise breastfeeding women to monitor the infant for seizures and vomiting." 6
Clinical Algorithm
Screen all pregnant women for tobacco use at first prenatal visit 1
Initiate behavioral counseling interventions immediately for all pregnant smokers (this has proven substantial benefit with no harms) 1
If behavioral counseling fails and severe tobacco dependence persists, engage in shared decision-making about pharmacotherapy options, but varenicline should not be offered due to insufficient safety data 1, 2
Consider nicotine replacement therapy (NRT) as an alternative if pharmacotherapy is deemed necessary, though evidence for NRT in pregnancy is also limited 1
Continue behavioral support throughout pregnancy regardless of pharmacotherapy decisions 1