Nobody knows how much alcohol can reduce your chances of conceiving but alcohol can reduce fertility, and excessive drinking can lead to early miscarriage. When trying to conceive your safest bet is to cut out alcohol altogether or at least , no more than one or two units of alcohol once or twice a week. Is an advisable limit.

The effects of alcohol are greater in women who drink large amounts of drinks containing caffeine, smoke and have a poor diet.

A unit is half a pint of ordinary strength beer, lager or cider, a small glass of wine or a single 25ml measure of spirit.

Women who are frequent drinkers are at risk of having babies with Fetal Alcohol Syndrome (FAS). This only usually occurs with higher levels of drinking, but even moderate alcohol intake (more than three units per day) can lead to mental and growth retardation, behavioral problems, and facial and heart defects.

One unit of alcohol is approximately equivalent to:

half a pint of ordinary strength beer, lager, or cider

a quarter of a pint of strong beer or lager

one small glass of wine

one single measure of spirits

one small glass of sherry

Reducing your alcohol
Try sticking to soft drinks
cut down on your caffeine intake also
ask your partner not to drink in the house
don`t keep alcohol in the house

If you think you may have a drinking problem, talk with your doctor or midwife or contact Alcohol Concern on 020 7298 7377.

Smoking
Smoking increases your chances of a miscarriage during the first trimester. Mothers who smoke are also more likely to go into premature labour; have a premature rupture of membranes; experience third trimester bleeding; have slower fetal growth, and deliver underweight babies. Prospective fathers who smoke should also quit, as exposure to “passive smoking” during pregnancy is also harmful. Smoking also impairs a woman's fertility. Smoking affects sperm and may impair male fertility too. You can't count on quitting smoking overnight, so it's best to start trying to withdraw from cigarettes well before attempting to conceive.

Caffeine
Pregnant women should limit themselves to the equivalent of one cup of coffee daily. Caffeine may increase the risk of late first or second trimester miscarriage. So start weaning much before conception.

Drugs
Illegal drugs are bad for your health, whether or not you are pregnant and they can only harm a baby. If you use them, it's imperative to stop before trying to conceive. Even over the counter drugs can do harm when trying to conceive and can even cause miscarriages.