Fewer babies are being born in the economic downturn
Newly-released US census figures show a strong slowdown in the birth-rate that began before the economic crisis hit.
The number of babies born grew by only 0.9% in the year to July 2008, compared with a rise of 2.7% the year before.
The figures have given rise to speculation that families anticipated hard times by having fewer children.
"If prospects look worse for families, they're going to be very likely to have fewer kids," said Mark Mather of the Population Research Bureau.
The surprising part of the figures is that they reflect family planning decisions made from early 2007, when there were only a few signs of an economic slowdown in the US.
The first real sign of the financial meltdown was in August 2007 when credit markets froze up, but unemployment was still low and consumer confidence high.
Stephanie Ventura, a demographer at the National Center for Health Statistics, which compiled the figures, told the Associated Press news agency it was too early to be sure why there were fewer pregnancies.
But "it is a very good question" to ask about the effect of the economic slowdown, she said. "They might have wanted to hold back" until economic conditions were more settled.
There were absolute declines in the number of births in 13 of the 50 US states, including some of the poorest, such as Louisiana and Mississippi, while North Dakota, which showed strong economic growth due to an oil boom, had the biggest increase in births.
High house prices, which peaked in 2006, may have also played a role in discouraging couples from having more children.
And more recently, there is evidence that immigration into the US has dropped sharply, further lowering the population growth rate.
Half of all children under five in the US are from minority households.