If giving birth were an Olympic event, Utah women would win the all-around team gold medal plus win several specific category contests among Americans.

Utah women had the nation's highest fertility rate in 2006 — for the "all around" — according to Census estimates released Monday. About one of every 12 Utah women of child-bearing age gave birth that year. Nationally, only one of every 18 did.

Utah also essentially earned gold medals for the lowest percentage of those giving birth who were unmarried, the lowest percentage who were in the work force, and the lowest percentage of births to mothers who receive cash public assistance.

"That's not a real shocker" about Utah scoring the top fertility rate, said Brooke Welsh, a labor and delivery charge nurse at Utah Valley Regional Medical Center in Provo. That hospital had 471 births last month, for example, about 15 per day.

"Usually, someone is in labor here. Rarely does it slow down to the point that you can sit down and do nothing. It's pretty consistent all the time," she said.

"It's clear that Mormon culture is what drives it for the most part," said University of Utah research economist Pam Perlich, who adds the fertility rate in Utah is higher than even in Mexico.

"Women get married here younger and have more babies here than the national average over the course of their whole life. The reason is the LDS culture" and its strong emphasis on families, she said.

Lois Bloebaum, manager of the reproductive health program for the Utah Department of Health, said a lesser, contributing factor could be "that Utah has no state funding for family planning services for low-income women, which is different from the other states."

Still, she said other surveys have shown that only about 30 percent of Utah pregnancies are unplanned, compared to a national average of about 50 percent. "Because Utah has one of the lowest rates of unintended pregnancy, that suggests the reasons for high fertility are philosophical or cultural," Bloebaum said.

Yet another reason why Utah's fertility rate may be high is a growing number of Hispanic women in the state, "and their fertility rate is higher than non-Hispanic whites," said Juliette Tennert, Utah state demographer.

She adds that the high fertility rate is nothing new. "Utah's birth rate on average has been 25 percent higher than the national rate over the past 50 years, and the trend obviously continues."