When preparing for IVF, it's natural to focus on medications, scans, and success rates — but what you do outside the clinic matters too. Habits like smoking, drinking alcohol, or having several cups of coffee a day can affect fertility, hormone balance, and even embryo quality.

But here's the good news: even small changes can make a difference. This post breaks down what the research says — without judgment — and offers realistic ways to reduce or eliminate these substances as you prepare for treatment.

Smoking and IVF: What the Science Says

Smoking is one of the most clearly linked lifestyle factors that negatively impacts fertility — for both women and men.

Effects on Female Fertility:

• Reduces ovarian reserve and accelerates egg loss

• Decreases oestrogen production, which is key for follicle development

• Increases risk of miscarriage and ectopic pregnancy

• Smokers often require higher doses of IVF medication and may have fewer eggs retrieved

Effects on Male Fertility:

• Reduces sperm count, motility, and morphology

• Increases DNA fragmentation in sperm, which can impact embryo quality

📈 Studies show smokers undergoing IVF have up to 40% lower success rates compared to non-smokers.

What You Can Do:

• Aim to quit smoking at least 3 months before starting IVF

• Ask your GP or clinic about nicotine replacement or support services

• If your partner smokes, their support in quitting helps your chances too

Alcohol and IVF: The Real Risks

Even small amounts of alcohol can interfere with fertility treatment. While one glass of wine isn’t likely to derail your cycle, regular drinking may reduce your success rate.

Why Alcohol Affects IVF:

• Disrupts oestrogen and progesterone levels

• Reduces egg quality and embryo development

• May increase the risk of implantation failure or early miscarriage

• For men, alcohol can impair sperm health and testosterone levels

📊 One study found that women who consumed more than four drinks per week had a 16% lower chance of a live birthper IVF cycle.

What You Can Do:

• Ideally, stop drinking 3 months before treatment — this covers the egg/sperm development window

• Choose alcohol-free wines, beers, or botanical mocktails to avoid feeling left out

• If you're struggling to quit, try cutting down slowly and get support if needed

Caffeine and IVF: How Much Is Too Much?

Unlike smoking and alcohol, caffeine in moderate amounts is not off-limits — but going over certain thresholds may increase risks.

What the Research Shows:

• High caffeine intake (>300mg/day) may be linked to lower IVF success rates

• Some studies suggest an increased risk of miscarriage with excess caffeine

• Too much caffeine can disrupt sleep and stress hormones, which indirectly affect fertility

🧮 A standard cup of coffee has around 95mg of caffeine. Energy drinks, cola, green tea, and even chocolate can contribute to your daily total.

Safer Limits:

• Stick to 200mg or less per day (roughly 2 cups of coffee)

• Switch to half-caf, herbal teas, or decaf when possible

• Be mindful of hidden sources (pre-workout drinks, dark chocolate, etc.)

Realistic Changes — Without the Pressure

Trying to overhaul your habits all at once can feel overwhelming — especially during the stress of IVF. Here’s how to approach it gently:

Phase Out Gradually:

• Swap one coffee per day for decaf or tea

• Start alternating alcoholic drinks with water or mocktails at social events

• Reduce cigarettes before quitting completely (with your doctor’s support)

Get Your Partner Involved:

• If you're in a couple, making changes together can reduce pressure

• Male fertility is just as sensitive to lifestyle factors — sperm quality responds to improvements in just 2–3 months

Be Kind to Yourself:

• IVF is already emotionally intense — don’t add guilt

• Celebrate small wins (like skipping one drink, or switching to herbal tea)

• Remember: these changes are about supporting your body, not punishing it

Every Choice Counts

You don’t need to be perfect — but being informed helps. Smoking, alcohol, and excess caffeine are all linked to lower IVF success rates. But making small, manageable changes gives your body the best chance to respond to treatment.

Think of this as part of your preparation — just like ordering meds or attending your scans. It’s not about fear. It’s about support, intention, and doing what you can.