When Chelsea Christensen found she was carrying twins, she was surprised, to say the least.

"I laughed really hard and I was really excited," said Christensen, 24, of Ogden. "I love babies ... it was fun to see two babies with the ultrasound."

Today is Mother's Day, and Christensen is one of the nation's estimated 82.8 million mothers who will be honored. The odds of delivering twins is one in 31, according to federal statistics.

Now, Christensen's twins are 2 years old. Her family will be celebrating at church and will have dinner at her parents' home. And the stay-at-home mom who works from home is looking forward to a facial and pedicure.

"I always request something fun for me," Christensen says, "something I can't go out and buy every day."

The first Mother's Day was organized in 1908 by Anna Jarvis in Grafton, W.Va., and Philadelphia. The celebration became popular across the country and in 1914 was recognized by Congress.

In Utah, the state with the nation's highest birthrate, women tend to marry and become moms at relatively young ages, said Juliette Tennert, the state's top demographer.

"Utah is unique," Tennert said. "We focus on family here, we get married at younger ages than the nation. ... We have more kids in Utah."

In Utah, an average woman is 23 years old when she has her first child, Tennert said. Nationally, the average age is 25.

And Utah has the nation's highest birthrate at 94.1 per 1,000 women in the childbearing years, according to the National Center for Health Statistics. Vermont's birth rate of 52.2 is the nation's lowest.

The trend, according to federal statistics, is that women are waiting longer to have children. The average age for having a first child has increased by nearly four years since 1970.

And, the proportion of women who are mothers is also decreasing. In 1976, only 10 percent of women age 40 to 44 weren't moms. Today that figure is 18 percent, according to census statistics.

Jo Ellen Ashworth of Bountiful is 62 and not a mother. But that doesn't diminish her dedication to children as an aunt to 12 nieces and nephews and a Primary teacher for young children at her LDS ward.

"If I get a Mother's Day present from a niece or a nephew, that's a bonus," she said. "Sometimes I do, and sometimes I don't. But they are very good to me all year."

Ashworth said her sister's six children are like her own. And she once had legal custody of a nephew so he could attend a gifted program.

"I lived in Salt Lake where the gifted programs were and he lived in Bountiful where they weren't," she said. "I drove to Bountiful every school day for six or seven years."