One recent data analysis suggests those in the top 1% are more likely to have 3 or more children:

In an analysis of the Federal Reserve’s recent Survey of Consumer Finances, Mike Konczal, vice president of policy and research at the left-leaning nonprofit Economic Security Project, found that 49 percent of U.S. families in the top 1 percent of incomes had three or more children, compared with 40 to 43 percent for most other income groups.
The same pattern held for the top 1 percent of earners by net worth; 50 percent of Americans in that group had three or more children.
This does not necessarily line up with the number of children Americans say they want to have:
Overall, Americans want an average of 2.7 children; they actually end up having an average of 1.6.
What might this lead to?
Haspel put it simply. “You don’t want children to be a luxury good,” he said.
This reminds me of sociologist Viviana Zelizer’s book Pricing the Priceless Child where she argues children shifted around the turn of the twentieth century from being economically valuable to emotionally valuable. Could we then see this as a continuation of a long process?
The article discusses policy implications. Multiple countries have tried financial incentives to promote adults having more children. Others argue it would take a larger reordering of the whole system to help potential parents. Is there anything that actually works right now on a broad scale?
And if this is the way it is playing out in people’s lives, at what point does the ideal number of children shift significantly? As noted above, there is a gap between how many children people have versus how many they want. What might happen to that gap in the coming years? Or what does that gap – hopes that are not realized – turn into?