The fertility rate in the United States is continuing to decrease. The most recent demographic assessment reported a fertility rate of 1.9, which is below the replacement level necessary for a population to grow.
This rate even puts the United States below some European countries such as France and England, which have been historically low.
The large generation of baby-boomers gave birth to the echo boom generation, who are now of childbearing age. Therefore, one would expect a growing population.
However, the decreased rate may be a result of the slow economy, as young people put off having children in hopes of saving money.