The effects of alcohol on a growing fetus are such that no woman pregnant, or considering pregnancy should drink alcohol. If they are drinking alcohol, they should stop drinking until after the pregnancy so as to minimize the effects of alcohol.
The effects from alcohol vary from the most serious, fetal alcohol syndrome, and then to less severe, but still concerned symptoms such as alcohol related neurological disorders and alcohol related birth defects. The above link gives more information on feta alcohol syndrome. In my career doing foster care I supervised a couple children who were living with their grandmother and had fetal alcohol syndrome. They were very difficulty with learning problems and behavioral issues. But at the same time they were beautiful children. That was some time ago, so they must be grown up now.