Caffeine, Alcohol, Smoking and Fertility: What Do the Guidelines Say?

When you start planning a baby, you may want to take a fresh look at your daily habits: your morning coffee, the occasional glass, maybe the cigarettes you are thinking of quitting. The good news: these areas are in your control, and the changes you make support both your fertility and your future baby. Let's look together at what current guidelines say.

Caffeine: no panic, just moderation. According to the UK's NICE fertility guideline, updated in 2026, no consistent link has been shown between caffeinated drinks such as tea, coffee, energy drinks and cola and fertility problems. However, you may not realize you are pregnant in the first weeks. The UK's National Health Service (NHS) recommends no more than 200 milligrams of caffeine a day during pregnancy, because too much caffeine has been linked to a higher risk of miscarriage and stillbirth. That is why staying under this limit while trying is also a smart habit.

How much is 200 milligrams? Approximate amounts given by the NHS:

• One mug of instant coffee: 100 mg (filter coffee and coffee from coffee shops may contain more)
• One mug of black or green tea: 75 mg
• One can of cola: 40 mg
• One 250 ml (about 8.5 oz) can of energy drink: 80 mg

According to the NHS, chocolate, guarana, some tablets and some sports supplements can also contain caffeine. So thinking about your total for the day, rather than counting single cups, is a good approach.

Alcohol: when trying to get pregnant, the safest choice is not to drink at all. NICE says the safest approach for women trying to get pregnant is to avoid alcohol completely. The NHS also notes that the safest way to keep risks to the baby to a minimum is not to drink alcohol at all. Because you may not realize right away that you are pregnant, this decision makes sense while trying too.

The male partner and alcohol: The NHS and NICE note that excessive alcohol harms sperm quality. According to NICE, staying within the UK's weekly limit of 14 units and spreading them over several days probably does not affect sperm quality. A unit here is a UK-specific measure and is not the same as a drink; a glass of wine usually counts as more than one unit. Still, cutting down or quitting alcohol together during this time also sends a strong message of support to your partner.

Smoking affects both women and men. According to NICE, fertility is probably reduced in women who smoke. In men, there is a link between smoking and lower sperm quality, but how big its effect on male fertility is remains uncertain. NICE stresses that quitting will improve overall health and that people who want to quit smoking should be supported. For detailed preparation for men, take a look at our Male Partner Fertility article.

Secondhand smoke matters too: NICE and the NHS note that being exposed to other people's cigarette smoke probably also affects a woman's chance of getting pregnant. According to the NHS, if your partner or someone you live with smokes, that smoke can reach you and the baby during pregnancy, and quitting can be harder when someone smokes around you. That is why it is much easier if quitting is a decision you make together.

What about e-cigarettes? According to the NHS, e-cigarettes are fairly new and there are things we do not yet know about them. Current evidence shows they are much less risky than cigarettes, because they do not produce tar or carbon monoxide. However, their vapor contains some of the harmful chemicals found in cigarette smoke, though at lower levels. The NHS says that if vaping helps you quit smoking, it is much safer than continuing to smoke. So e-cigarettes can be considered a tool for quitting, but they are not completely risk-free.

Start with small steps:

• Cut down your coffee gradually, swapping one cup for a decaf drink
• Bring alcohol-free drink options to social occasions
• Set a date to quit smoking and ask your family doctor for support
• Make your home and car completely smoke-free

When should you see a doctor?

• You are finding it hard to quit smoking or alcohol on your own
• You have not gotten pregnant after a year of trying (the NHS recommends going sooner if you are 36 or older)
• You used alcohol or cigarettes before you found out you were pregnant and you are worried

Dear mom-to-be, no one has to be perfect overnight. Every cigarette you give up, every glass you skip and every cup you cut back on is a small but precious promise to your future baby. Walk this path together with your partner.