When did it start to become well known that one shouldn't get drunk while pregnant? In the book, the main character gets angry at his wife for other reasons, but it's not ever presented as something that could be harmful to the child, just as something annoying the parent is doing. Was this common at the time?
A French study in 1968 first made the link between drinking and fetal defects. "Fetal Alcohol Syndrome" was coined as a term in 1973. And the Surgeon General first recommended pregnant women not drink alcohol during pregnancy in 1981. So basically, in the US, it wasn't really heard of until the 1970s, and it took awhile for the news to trickle into the public consciousness. The New York Times first published an article mentioning fetal alcohol syndrome on July 3, 1973. Initially the concern was for the children of alcoholics, and later the concern was extended to social drinkers.
Anecdotally: the writer Michael Dorris wrote the fictionalized account of his own adopted son's fetal alcohol syndrome. It was called The Broken Cord published in 1989. It was one of the things that helped publicize the existence of fetal alcohol syndrome. When he adopted his son in 1971, born to an alcoholic woman who was drunk during the childbirth, he said no one had any clue that this sort of problem existed, and for him, it was a huge ordeal to gradually uncover what happened and why his son had the problems he had.