I worked on the assumption if you wouldn't give it to a baby ease off having it yourself, in terms of guidelines.
The control is an interesting question though. When I was pg with ds1 I was at a wedding, I had not drank for the duration, but my FiL had (at my request) poured me a small glass of wine which I had kept back for the toasts.
A man at our table had been steadily drinking and reached over to take my glass "stating that's not for you, I'll take care of it for you", when I objected he was utterly incredulous and kept insisting I was not allowed to drink it, and "it wasn't on" despite myself and others at the table pointing out it was fine.
About 5 minutes later after everyone forcibly changing the conversation, my dh wanted my attention (he was Best Man) before I had got a metre from the table he leaned over, snatched my glass and drained it.
FiL and others were furious, I returned to various tempers, his poor wife was alternating between mortified and silently fuming (she had been in the toilet for his initial outburst). He then insisted "it was for you're own good, you do not drink when pregnant". FiL went to the bar and purchased me a glass of wine and he was frostily ignored until he sat elsewhere. (His wife apparently went nuts at him later).
From my POV, their are many conditions you can have that mean you cannot consume alcohol. Pregnancy is a very visible condition though, and one that makes you physically weaker and vulnerable than in your normal state. This (admittedly drunk, but still no excuse) man used my condition to bully and coerce me into handing over my drink. He then used it to justify stealing from me.
If I hadn't been pregnant, he would not have attempted to control me.
But I can't decide whether the vulnerability of pregnancy is the issue, or the alcohol guide lines.