My husband drinks. Does that cause possible birth defects or any concerns for our baby?
How much drinking? If you're referring to an alcoholism situation, besides increasing the risk of infertility and miscarriage, especially if compounded by age, you also need to worry about his ability to raise a child. Fatherhood is more than just providing sperm, of course.
If it's in moderation--an occasional beer, cocktail, or wine, there shouldn't be any concern. But there's no study that has determined what the maximum safe amount is, nor can there be, so it's a judgement call on your part. Chances are if the drinking is interfering with other aspects of your relationship, that's enough to increase other risks. If it's purely a social consumption, in moderation, there's no need to heed dramatic warnings.