Give it to me straight...

Does alcohol have any effect on fertility?

My wife and I have been trying for about 4 years.
The first time she got pregnant was after about a year or so of trying.
She's been pregnant in total three times:
1) I had not been drinking for a about 6 months
2) It was a few months after the first miscarriage and I don't remember what I was drinking.
3) I stopped drinking for about 2 months and she got pregnant.

The first pregnancy and third were about a year + apart. I've been drinking regularly (aka - maybe 3 beers a night? Nothing too intense imo)

There may be other issues, but I just keep thinking about me drinking beer and its effect on me. (She doesn't drink at all so it's not an issue with her)

What's the scoop?