The Comparative Effectiveness of Varenicline and Nicotine Patches for Smoking Abstinence During Pregnancy: Evidence From a Population-based Cohort Study.

This study is the first to measure the comparative effectiveness of varenicline and nicotine patches during pregnancy - women using varenicline were almost three times as likely to quit smoking than those using nicotine patches. This study addressed a clinically important question using an observational study, noting that there is an absence of evidence from randomized controlled trials because of the ethical issues associated with including pregnant women in clinical trials of medicines of unknown safety.