Drinking alcohol during pregnancy can cause fetal alcohol syndrome (FAS), which is associated with stillbirths, physical and mental retardation and brain damage. Even moderate alcohol use can cause infertility, miscarriage, placental abruption (separation of the placenta from the uterine wall) and low birth weight babies.

Alcohol interferes with your body's ability to absorb folic acid, which is essential for the fetus' development, especially of the brain and nervous system during the first trimester. Some doctors feel comfortable allowing women to drink a glass of wine per week during the third trimester – but remember that alcohol is going straight into your fetus' bloodstream, too.