This would be Romania, specifically shortly before and during the fall of communism, there were all kinds of weird incentives in place to encourage the birth rate, for example military engineers (like my FIL) where able to get out of deployment to rural infrastructure projects if they had a (pregnant) wife or a newborn. So a good chunk of his unit had children in a span of give or take 4 months, which coincidentally was about a year after an upcoming deployment to build a dam in a godforsaken area of the country was announced.