For white non-Hispanics, a little over 600k births in 1992 were the third live baby or higher. This represented just under 1/4 of all births. Over 75% of all births for 1992 were first or second births.
The approximate distribution of the 600k higher birth orders (less than 100% due to rounding) was:
3rd order: 66%
4th order: 22%
5th order: 7%
6th order: 2.6%
7th order: 1%
8th order or higher: 1.1%
In 2014, there were over 50k fewer such births, a bit over 550k and that represented just OVER 25% of all births for that year.
The distribution of these 550k higher-order births over 20 years later was:
8th or higher: 2%
The total births for 1992 were around 2.5 million, while for 2014 they were around 2.1 million. So people were having fewer children overall, but the ones having many are chugging along pretty impressively. The problem is that there’s no filtering for how much of that chugging along is in little horse-powered buggies, so there’s that to keep in mind.
To put this distribution of higher-order births in context, here’s the “white” distribution for 1970, ten years after the Pill and IUDs were introduced.
Total white births: approx 3.1 million
Total third or higher order white births: approx 1 million
Percentage distribution of third and higher order births:
Admittedly this includes some Hispanics, but only about 4-5%, not enough to shift the overall pattern. This pattern from 1970 could be returning at the higher orders, but it’s too soon to tell.