The critical dose for alcohol consumption during pregnancy has not been determined. It is believed that 'binge' drinking has more detrimental effects on the fetus than a background alcohol consumption.
Alcohol consumption is associated with symmetrical growth retardation. Alcohol influences fetal development particularly in the first trimester. Excessive alcohol intake is associated with the development of fetal alcohol syndrome.
There is a reported increased incidence of spontaneous abortions in pregnant mothers who drink alcohol.
NICE state that (1):
- pregnant women and women planning a pregnancy should be advised to avoid drinking alcohol in the first 3 months of pregnancy if possible because it may be associated with an increased risk of miscarriage
- if women choose to drink alcohol during pregnancy they should be advised to drink no more than 1 to 2 UK units once or twice a week (1 unit equals half a pint of ordinary strength lager or beer, or one shot [25 ml] of spirits. One small [125 ml] glass of wine is equal to 1.5 UK units). Although there is uncertainty regarding a safe level of alcohol consumption in pregnancy, at this low level there is no evidence of harm to the unborn baby
- women should be informed that getting drunk or binge drinking during pregnancy (defined as more than 5 standard drinks or 7.5 UK units on a single occasion) may be harmful to the unborn baby
The Chief Medical Officers' guideline is that (2)
- If you are pregnant or planning a pregnancy, the safest approach is not to drink alcohol at all, to keep risks to your baby to a minimum
- Drinking in pregnancy can lead to long-term harm to the baby, with the more you drink the greater the risk.
- NICE (March 2016). Antenatal care for uncomplicated pregnancies
- DOH (January 2016). How to keep health risks from drinking alcohol to a low level: public consultation on proposed new guidelines.