- Male cannabis use once or more times per week in the 2 months prior to conception was associated with an approximate doubling of the risk of spontaneous abortion (SAB) in his partner.
Why this matters
- As cannabis use is common and increasing with decriminalization, clinicians should be aware of this factor in pregnancy loss.
- Prospective study using Pregnancy Study Online preconception cohort.
- Females 21-45 years; males ≥21 years; attempting to conceive; not using fertility treatment.
- Male cannabis use in 2 months prior to baseline: none;
- Follow-up with female partner for 12 months or until pregnancy reported.
- SAB defined as pregnancy loss at
- Study funded by National Institutes of Health.
- n=1535 couples.
- Total SABs: 17.5%.
- Only users ≥1 time/week had elevated SAB: adjusted HR (aHR) vs nonusers: aHR, 2.04 (95% CI, 1.28-3.24).
- Only users ≥1 time/week had elevated aHR for ≥3 cycles pregnancy attempts at baseline vs nonusers (aHR, 3.8; 95% CI, 1.7-5.0).
- SAB risk was higher at
- No data on time-varying cannabis use.
- Cannabis exposure misclassification likely.
- Possible selection bias.
- Residual confounding.