How long should men discontinue Tetrahydrocannabinol (THC) use before attempting conception?

THC Discontinuation Before Conception for Men

Men should discontinue THC use for at least 3 months before attempting conception to minimize risks to sperm quality and potential offspring development.

Evidence on THC and Male Fertility

THC use has been associated with several negative effects on male reproductive health that may impact fertility and offspring outcomes:

• Recent and heavy marijuana use is associated with abnormal sperm motility (asthenozoospermia) and morphology (teratozoospermia) in men being investigated for infertility 1
• Paternal THC exposure in animal studies has shown long-lasting behavioral consequences in offspring, including increased risk-taking behavior and memory function impairments 2
• THC can negatively affect sperm quality, which may compromise fertility potential 3

Recommended Discontinuation Timeline

The recommended discontinuation period is based on several factors:

1. Spermatogenesis cycle: One complete cycle of spermatogenesis requires approximately 74 days (about 3 months) 4
2. Clearance of substances: This timeframe allows for the elimination of THC and its metabolites from the reproductive system
3. Sperm quality recovery: Studies suggest that sperm quality parameters may improve after a period of abstinence from THC 1

Comparison with Other Substances

This recommendation aligns with guidelines for other substances that may affect male fertility:

• Methotrexate: Men should wait 3 months after discontinuing methotrexate before attempting conception 4
• Cyclophosphamide: Should be discontinued at least 3 months prior to attempting conception 4
• Zika virus exposure: Men should wait at least 3 months after symptom onset or last possible exposure before trying to conceive 4

Clinical Considerations

When counseling men about THC discontinuation before conception, consider:

• Dose-response relationship: Higher quantities of marijuana use are associated with greater risk of abnormal sperm parameters 1
• Recency of use: Recent users have 2.6 times higher risk of abnormal sperm motility compared to non-users 1
• Combined risk factors: Men with other risk factors for reduced fertility may be more vulnerable to the effects of THC

Practical Recommendations

1. Screen all men planning conception for THC use
2. Advise complete discontinuation at least 3 months before attempting conception
3. Explain the rationale for discontinuation in terms of improved sperm quality and reduced risks to offspring
4. Consider semen analysis for men with history of heavy or long-term THC use
5. Address withdrawal symptoms if needed and provide support for discontinuation

While some studies show limited overall association between marijuana use and fecundability 5, the potential risks to sperm quality and offspring development warrant a cautious approach. The 3-month abstinence period provides sufficient time for new sperm development and elimination of potential negative effects of THC exposure.