NICE said there may be an increased risk of miscarriage during this period, despite uncertainty over whether the odd drink during pregnancy will harm their baby.
Dr Gillian Leng, NICE deputy chief executive, said: ‘We recommend that doctors and midwives should advise women to avoid drinking alcohol when trying to get pregnant and during the first three months of pregnancy.
‘If they do choose to drink while pregnant, women should be advised to drink no more than one to two units once or twice a week, and to avoid binge drinking because this can harm their unborn baby,’ she said.
Drinking more than 7.5 UK units a week is considered binge drinking and pregnant women are urged not to exceed this level.
NICE also recommends that all women are informed about the importance of the health of themselves and their baby at the booking appointment and that screening for sickle cell diseases and thalassaemias are offered as early as possible.