Washington, Oct 4 (IANS/RIA Novosti): Birth rates in the US fell for the fourth straight year, the government said Wednesday.

Experts blamed the bad economy for low birth rates.

"Children are very expensive and people may look at the situation and think this is not the best time," said Brady E. Hamilton, lead author of a government report.

But, Hamilton said it is "not really a matter of births foregone, but births postponed," as the study also revealed the birth rate for women 35 and older rose.

Birth rates for women in their early 20s dropped, and Hamilton said younger women have the "option of postponing having a child for a few years."

Fewer than four million births were counted in 2011, a one percent drop from the year before, and the lowest number of births since 1998, according to the report of the Centers for Disease Control and Prevention.

The report's most significant findings show that the birth rate for Hispanic women declined by six percent and birth rates for teenagers are at a historic low, dropping by 49 percent since 1991.

There was a one percent decline in the number of births for white women and a two percent decline in the birth rate for African-Americans.

The birth rate for single women dropped by three percent in 2011, and the birth rate for married women rose by one percent.

Cesarean sections, which had been rising since 1996, accounted for about one-third of all deliveries in 2011, Hamilton said.