There are a couple of other reasons for Cuba's birthrate problems.
The first one is a health care system that provides abortions for free. I heard from one of these young Cubans that hospitals in Cuba have more abortions than births. Abortion is hailed as part of a woman's health care package. The result is that very few women are choosing to have babies.
The second factor is that the regime marginalized faith and the church. As we see in the U.S., religious young men and women are more likely to get married and have children. My parents' Cuba was a very Catholic and traditional country. Today's Cuba is nothing like that!
We often talk about the dinosaurs who run Cuba, or the 80-something Castro brothers and all of those aging members of the political class. Needless to say, they are not the only ones getting old.
The entire island is a demographic disaster!