The researchers wanted to know if how rich a country is affects how successful assisted reproductive technology (ART) treatments are. They looked at data from the International Committee for Monitoring Assisted Reproductive Technologies (ICMART) to see if there's a connection between a country's wealth (Gross Domestic Product per person) and the success of ART treatments like getting pregnant and having a baby. They found that in countries with a GDP per person over $13,000, the success rates of ART treatments didn't change much even if the country was richer. In the USA, however, there was no clear link between ART success rates and how rich a state was. Overall, once a country reaches a certain level of wealth, the success rates of ART treatments tend to stay stable, regardless of how rich the country gets afterward.