Overview

• Heavy drinking among women highly determined to avoid conception raised their unintended pregnancy risk by about 50% compared with moderate or non-drinking peers.
• Cannabis use was not associated with an increased unintended pregnancy rate, with 28 of the 71 pregnancies occurring in frequent users.
• The study tracked over 2,000 non-pregnant women aged 15–34 across five southwestern US states and focused on 936 participants with the highest Desire to Avoid Pregnancy scores.
• Researchers collected baseline self-reported substance use only once and enrolled patients from safety-net clinics, which may limit the broad applicability of results.
• Lead author Dr. Sarah Raifman recommends integrating alcohol reduction strategies into preconception care to prevent unintended pregnancies and reduce fetal alcohol spectrum disorders.