What lifestyle habits hurt fertility?

The lifestyle habits most consistently linked to reduced fertility are smoking, including cannabis, heavy alcohol use, very high caffeine intake, chronic sleep disruption, and carrying substantially more or less body weight than a healthy range for you. Most of these lifestyle habits that hurt fertility are modifiable, which means there is real room to shift the odds.

The habits with the strongest evidence

Smoking stands out. A large meta-analysis cited in reproductive guidance found that women who smoke are significantly more likely to experience infertility, and smoking is associated with earlier menopause and higher miscarriage risk. Heavy alcohol use and very high caffeine intake are each linked to longer time to conception. Cannabis is associated with lower sperm counts in men and reduced fertility signals in women. Extremes of body weight in either direction can disrupt ovulation and hormone balance, and exposure to certain endocrine-disrupting chemicals and air pollution may also play a role.

RELATED: What lifestyle habits support fertility?

What the research suggests

The 2022 ASRM committee opinion on optimizing natural fertility summarizes the evidence and offers a reassuring nuance on caffeine: moderate intake of about one to two cups of coffee per day before or during pregnancy has no apparent adverse effect on fertility. It is high intake, roughly five or more cups a day, that has been associated with reduced fertility. Smoking and cannabis carry clearer signals of harm across the literature.

Practical takeaways

• If you smoke or use cannabis, quitting is one of the most impactful changes both partners can make
• Keep alcohol low while trying to conceive
• Enjoy coffee in moderation, since one to two cups a day appears fine
• Aim for a body weight that feels sustainable and healthy for you, rather than a specific number
• Reduce everyday exposure to endocrine disruptors where practical, such as swapping some plastic food storage for glass

When to talk to your provider

If you are working to change a habit like smoking and want support, or if you are unsure how a medication or health condition affects your fertility, your provider can help you build a realistic plan.

Frequently asked questions on habits and fertility

Do I have to give up coffee completely? 
No. Current guidance suggests moderate caffeine, around one to two cups of coffee a day, does not appear to harm fertility.

Does cannabis affect fertility?
Research associates cannabis use with lower sperm counts in men and reduced fertility signals in women, so pausing while trying to conceive is reasonable.

The habits that work against fertility are, for the most part, the same ones that work against overall health. That overlap makes them a practical place to start.

A note from WeNatal: small swaps, steady progress

You do not have to overhaul everything at once. Consistency matters more than perfection. If you want a starting point tailored to where you are in your journey, the WeNatal quiz can point you toward the right products and habits.