Posh Spice has three, and says she'd love more. Will Smith and Jada Pinkett have three. So do Tom Cruise, Angelina Jolie, and Madonna, thanks to adoption. With celebrities breaking the two-kid barrier, big families suddenly seem as trendy as jumbo-sized sunglasses and handbags.

And if you read the news reports, you might think it's not just Hollywood but regular American families that are going super-sized. "Get ready for the new baby boom," proclaims a headline from Life magazine. "For more parents, three kids are a charm," says USA Today.

We decided to cut through the buzz and find out whether big families really are on the upswing, and — more important, if you're one of the 50 percent of BabyCenter moms who want a big family — what life is like for multiple-kid moms. Here's what the experts, both the academic and the real-mom kind, had to say:

Are big broods back?

Not really, says Steve Martin, a sociologist at the University of Maryland. When Martin crunched the numbers from a 2004 government survey — the most recent available — he found that 28 percent of women age 35 to 44, who are winding up their childbearing years, have three kids or more. Ten years ago, it was 29 percent. The numbers for younger women haven't budged much, either.

Martin says it's not so much that big families are back, as that they never disappeared in the first place. "Large families have consistently been common," he points out. "Two is the norm, but for every 34 mothers who stop at two, there are 28 who have three, four, or more."

So why does it suddenly seem like you can't walk down the street without tripping over a double-wide stroller and a few toddlers?

Despite the nationwide numbers, big broods could be a trend in certain areas, says S. Philip Morgan, sociologist and demographer at Duke University. "You do get clusters of behavior that are very real," he says. "But it's not appropriate to generalize them across the country, because there are other pockets that are behaving very differently."

Morgan doubts that America will see a 1950s-style baby boom — when women had four kids, on average — anytime soon. "My forecast is more of the same in the United States," he says. "There are people who want substantially more than the two-kid average, but that's been going on for a long time."

Who's having three or more kids

While the percentage of moms having Brady Bunch-sized broods has held steady, the women who make up their ranks have changed somewhat. These days, professional and wealthy moms are having bigger families — traditionally more common among certain religious groups and poorer women with less education, according to government surveys.

Professional moms have twice as many kids at home, on average, than their high-powered counterparts did back in 1977, according to a 2002 report from the Families and Work Institute. And in a 2000 study, sociologist Martin found that college-educated women who put off motherhood until their 30s are suddenly having families almost as big as everyone else's. "That's historically unprecedented," he says.

Carolyn Moe fits the profile of this new kind of big-family mom. The mother of three is vice president of sales for a global technology company, and says she never doubted she could combine a successful career with more than two kids. "In the past, women may have felt they had to fit some label of what a working woman should be. This generation is all about creating the life you want," she says.

Wealthier families in general seem to be warming up to the idea of moving past a tasteful two. "Our survey from 2002 found that 12 percent of higher-income women had three or more children," says Anjani Chandra, a researcher at the National Center for Health Statistics. "The figure from 1995 is only about 3 percent."

Part of the reason that wealthier people are having more kids may simply be that there are more of them. "In this country there's been a pretty dramatic increase in people with higher incomes," says demographer Morgan. "And if you like kids and can afford them, why not?"

Finances played a role in the Newmarks' three-kid family. Mom Kate says she and her husband, who runs his own engineering business, discussed how they would be able to comfortably afford each child. "We talked about whether I would be able to stay home," she says. "And with each kid we were like, 'Here's another college tuition.'"

It may seem as though women such as Moe and Newmark have nothing in common with the more stereotypical big-family mom — working class, religious. But there is a common thread, says Julie V., who was at one time the moderator of BabyCenter's Large Families bulletin board and mother of four. Julie saw all sorts of women on the board, and the only description that fit them all, she says, is the obvious one: They love kids and want lots of them.

Pediatrician JoAnn Rohyans of Columbus, Ohio, says that's what unites her big-family patients, too. "They just really enjoy their kids and think that two is not enough. They don't want their jobs as parents of school-age kids to end so quickly!"

Why moms want large families

Statistics show that big broods tend to, well, run in families: Women who grow up with lots of brothers and sisters are more likely to have lots of kids themselves. But on our Large Families bulletin board, that's not the case.

"Some of our moms are onlies, and most have just one or two siblings," says moderator Julie V. And at least a few of them are looking to give their own kids the companionship they say they missed out on.

"I was an only child," says Patience Soares, mother of five. "I always get so jealous of people who are close to their siblings. My husband's family does everything together — birthdays, Christmas, cookouts. I want my kids to have that. And they'll always have each other, even if something happens to us."

Others say they wound up with bundles of babies because the more they had, the more they enjoyed it. "I always say that after three, it's all downhill," says Leslie Biskup, who's working on number six. "I'm so much more relaxed and patient than I was with my first two."

Newmark hadn't planned on having any kids, let alone three, but says that once she became a mother she felt a strong urge to expand her family. "It's hard to put into words, but I just didn't feel done," she says. "I felt like there was someone not here who should be here."

What's life like for big-family moms?

In a two-kid country, a basketball team-sized brood can attract attention, not all of it friendly. "I've heard everything from, 'Five kids, are you nuts?' to, 'You do know what causes pregnancy, right?'" says Billie Jean Sheffron.

Almost all the moms in this story report getting at least the occasional nasty comment, sometimes from their own family. "Every time I tell my mother I'm pregnant she rolls her eyes," says Leslie Biskup. "She says she's supportive, but my parents just don't get why I'd want so many kids."

The most common query isn't mean, though, just curious: "You must have your hands full. How do you do it?" The questioners have a point. Five kids may mean five times the love, but it's also five times the mess, the meal planning, and the chauffeuring.

"I think the hardest thing is how relentless it is," says Talitha Gawkoski, mother of seven. "There is always dirty laundry, no matter how many times you do the wash. Someone is always hungry, no matter how much food you provide."

That said, our moms make it clear that a big-family home may take a lot of work, but it's not as chaotic as some small-family parents might imagine. Most mothers we spoke with who have five, six, seven, or even eight kids have spaced them out fairly widely, and often the eldest are grown and out of the house. And even if they're all still at home, the parents are rarely wrangling all of them, from teenagers to toddlers, at once. "In a way it's like having two families, the little kids and the big kids," says Leslie Biskup.

They also say that parenthood goes more smoothly when you have more experience under your belt. "Going from no kids to one kid, and from one to two kids was actually the harder transition," says Melissa Brown. "By the time the fourth came around, it was like, 'Welcome to the family.' No big deal."

Another common question — how do you afford it? — is also worth asking. You don't have to be rich to afford a large brood, but you probably will have to make some sacrifices. Most of our moms spoke of having a smaller house, older cars, and fewer fancy vacations than their small-family neighbors. "Other people have things, we have children," says Talitha Gawkoski.

But Gawkoski and other large-family moms are happy with the trade-offs. They made the decision to have a big family with their eyes wide open, and wouldn't change a thing if they could. "Everywhere I look I see someone I love, and they're all such wonderful people," says Gawkoski.

Are big families good for the kids?

Most big-family moms think that all the sibling togetherness, including the squabbling, teaches their kids a lot about how to love and get along with others. "To me one of the biggest advantages is that they learn so much from each other, and at such an early age," says Sherry Welden, mother of six. "They learn responsibility, how to share, and how to care for each other. I really notice a difference between my kids and kids from smaller families."

The idea that brothers and sisters teach each other social skills is a popular one among big-family moms, and there's research to back it up. A 2004 study of more than 20,000 kindergarteners across the country found that teachers rated students who had at least one sibling as having an edge in social skills: better at making friends, better at helping other kids, and more tuned to the feelings of others. (The catch: having any siblings was what made the difference, and kids with lots of brothers or sisters didn't have any advantage over those who had just one.)

Researchers have also turned up some downsides to big families, although experts argue about how valid they are. About a hundred years of studies — from the 1870s to the 1970s — found that on average, the bigger the family, the lower the intelligence of the kids. One theory holds that as a family grows, the parents have less time and money to devote to each child's education and intellectual development.

But some researchers think IQ scores have more to do with socioeconomic characteristics — large families are still more common among low-income parents with less education, and kids tend to match their parents' academic achievement. "It's factors like income and education that the studies are actually measuring," says psychology professor Joseph Rodgers of the University of Oklahoma.

Rodgers also believes the effect of family size on both intelligence and social skills pales in comparison to parenting styles.

"Imagine two households, one with four children and one with two," he says. "In one household the parents spend a lot of quality time with their kids, the house is filled with books, and the food on the table is nutritious. In the other the parents pretty much ignore the kids and sit around watching TV. What do you think is more important: The number of children or the quality of the parenting?"

BabyCenter Seven: Life lessons from large families

How do you do it? That's one of the questions our big-family moms hear most often. Every family does it differently, but our moms did have this advice to share with anyone contemplating a bigger brood: