Income and the birth rate
Income and high birth rates are strongly linked, not just in the United States, but around the world. Women in lower income brackets tend to have higher birth rates across the board. There are many factors at play in birth rates, such as the education level of the mother, ethnicity of the mother, and even where someone lives.
The fertility rate in the United States
The fertility rate in the United States has been falling steadily, and it seems that more and more women are waiting longer to begin having children. In 2017, the average age of the mother at the birth of their first child was 26.8 years old, although this figure varies for different ethnic origins.