Alcohol
Official guidance advises that if you’re trying to have a baby, you should stop drinking alcohol. This is to protect the baby in case you’re pregnant and don’t realise it. If you are worried about how much you have been drinking in the early stages of pregnancy, you should talk to your GP or midwife.
However, alcohol doesn’t cause problems only once you are pregnant. There is evidence that alcohol can affect fertility in both men and women. It’s another reason why, if you’re trying to have a baby, both you and your partner might want to cut back on drinking.
Drinking over the guideline amounts also puts you at higher risk of miscarriage during the first trimester. A large study found a more than three times increased risk of miscarriage in women drinking just five or more units per week.
Not drinking alcohol is the safest approach
Drinking alcohol at any stage during pregnancy can cause harm to your baby and the more you drink, the greater the risk. This is why the low risk drinking guidelines advise pregnant women that the safest approach is to not drink alcohol at all during pregnancy.
If you’re pregnant or think you may become pregnant, you’re also advised not to drink. But please be aware if you’re already pregnant and drank only small amounts of alcohol in the early stages of pregnancy, the risk of harm to the baby is low. However, if you are worried, you should talk to your GP or midwife.
The Department of Health recommends that women who think they may become pregnant should not drink alcohol at all; this is to keep risks to the baby to a minimum.
Useful links
https://www.nhs.uk/conditions/pregnancy-and-baby/alcohol-medicines-drugs-pregnant/
Drugs
If you took a drug without realising you were pregnant on a one-off occasion, try not to worry – it's unlikely to have affected your baby. But if drugs are part of your life, getting help can really improve the outlook for you and your baby.
Using illegal or street drugs during pregnancy, including cannabis, ecstasy, cocaine and heroin, can have a potentially serious effect on your unborn baby.
If you regularly use drugs, it's important to tackle this now you're pregnant.
It's best not to stop abruptly without first seeking medical advice as there may be withdrawal problems or other side effects.
https://www.nhs.uk/conditions/pregnancy-and-baby/illegal-drugs-in-pregnancy/