Gas prices, food prices and climate change are all factors when looking at a demographic trend of this magnitude.
Miriam Vourgourkakis gave birth to a daughter today in a Los Angeles hospital. She and her husband Yanni already have a son who is a year and a half old.
"When I told him we're having a girl, he said, 'Check please,'" Vourgourkakis said, laughing.
Her husband agreed that after two children, they were done.
Most Americans stop at two, but even at that rate, the numbers add up fast. And while experts say its too soon to tell if it's a bona fide baby boom, the numbers speak for themselves.
ABC News' Lauren Sher contributed to this report.