News that Janet Jackson is pregnant at age 49 has been met with no shortage of curiosity (donated egg?) — or judgment.

It's a rare older mother (usually defined as being 37 or older) who hasn't faced some unkind commentary regarding her growing belly.

She's being selfish.

She's putting herself, and the baby, at risk.

She'll be forever mistaken as Grandma.

And just try to find a playgroup.

We might want to rethink all that, not just because it's uncharitable, but because new research suggests a different reality — except maybe for that playgroup.

While health concerns are real, most older moms manage well during their pregnancies and report great satisfaction as parents. Perhaps most interesting, the benefits to their children outweigh the biological risks.

Children born to older mothers are less likely to quit school and more likely to attend a university, and tend to perform better on standardized tests than siblings who were born before them, said Kieron Barclay, a researcher with the London School of Economics and co-author of a large study published in April in Population and Development Review.

Kids born to older mothers are taller, too, he said.

Barclay, with Mikko Myrskylä of the Max Planck Institute for Demographic Research, looked at more than 1.5 million Swedes born between 1960 and 1991, examining the relationship between a mother's age when she had her kids and certain attributes of those children.

"The main finding in our paper was that, for any individual woman, delaying childbearing or continuing childbearing at an older age means that their children do better," Barclay said. The reason, Barclay said, is that every year mom waits to carry that baby is another year of improvements in medical care, knowledge, social and environmental conditions.

"For example, a woman born in 1950 who has a child at age 20 gives birth in 1970," he said. "If she waits until age 35, she gives birth in 1985." Improvements over time counterbalance, or even outweigh, the negatives for children born to older mothers, he said.

"We were most surprised to find that this applied even to children born to mothers older than 40."

Similar positive results have been noted among American and British children.

Rare, but growing

While the number of older mothers remains small, entertainer Jackson (who hasn't officially announced her pregnancy) is part of a, well, growing trend. The number of births to women ages 45 to 49 rose by 3 percent in 2014, according to the Centers for Disease Control and Prevention.

Births by women ages 50 to 54 grew from 255 in 2000 to 743 in 2014. Most moms in this age group conceived using in vitro fertilization, sometimes with their own eggs, other times with a donor's eggs.

Concerns such as Down syndrome and other genetic abnormalities can be minimized if younger donor eggs are used, but health risks are real. Older women with diabetes, high blood pressure or obesity may face additional complications in pregnancy. That's why women surprised by a late-in-life pregnancy, or those who want to get pregnant, should consult with a specialist.

One big — and largely unaddressed — risk is the feeling of isolation that many older moms experience. But the number of websites and blogs offering guidance, tips and empathy is exploding. There's motherhoodlater.com, ­grayhairedmom.com and my favorite (having given birth to my third child at 39), antiquemommy.com.

One Twin Cities Meetup group, called Later-in-Life-Moms-in-Minneapolis-St-Paul-Metro, lists nearly 90 members, including one 44-year-old mother of a 3-year-old nearly desperate to find women with this shared experience.

"I need support!!!" she wrote. "All my friends have older kids that are mostly out of the house now. They are just not really understanding when it comes to me not having the energy of being able to do the things I used to do."

Others openly and honestly mourn the loss of spontaneity with their partners, of being unable to travel effortlessly, of not saving more money, of picturing being 60 or 70 when that child begins college.

Plenty of positives

Drained energy and emotional roller coasters aside, older mothers typically step up to the plate with joy and much to offer their children.

"By the time you're in your late 30s or early 40s, you already have a few decades of real life experience," said Dr. Donna Block, an obstetrician and founder of Clinic Sofia in Edina and Maple Grove.

"You're established in your career, you're economically comfortable enough, and you probably are a little better prioritized about how to spend time and money. Women who come to me at this point, who make the choice, really want it and are committed to changing their lives."

Barclay's co-author Myrskylä emphasized, however, that their study is not meant to be taken as a family-planning guide. The findings simply suggest that for older women who are gifted with a healthy baby, that child may enjoy certain advantages down the road.

Or sooner.

One Twin Cities woman who had her first two children in her 30s, then her third child at age 45, sees a positive difference in how she parents now.

While not about to "get in that swimming pool" again, she said with a laugh, she finds that "things are not as dramatic" with parenting in general.

"I worried too much early on," she said. "I micromanaged too much. I tried to control too much. I feel less anxiety now.

"You know it's going to work itself out."

gail.rosenblum@startribune.com 612-673-7350 • Twitter: @grosenblum