New York ? Laura Bennett isn’t bound by convention. Professionally, at age 42, she’s pursuing a midcareer switch into big-time fashion design. At home, she’s a mother of five – with No. 6 due next month.

“It was nothing that we planned ahead of time,” Bennett says. “It’s more that we were enjoying all the kids.

“We have a happy home. Why not have as many children as we can?”

It’s barely a blip on the nation’s demographic radar – 11 percent of U.S. births in 2004 were to women who already had three children, up from 10 percent in 1995. But there seems to be a growing openness to having more than two children, in some case more than four.

The reasons are diverse – from religious to, as Bennett reasons, “Why not?”

The families involved cut across economic lines, though a sizable part of the increase is attributed to a baby boom in affluent suburbs, with more upper-middle-class couples deciding that a three- or four-child household can be both affordable and fun.

The Bennetts still stand out. Among other well-off families in Manhattan, three children generally is the maximum – one or two is much more common as parents contemplate private-school tuition of $25,000 a year even for kindergarten, and a real estate market that is far from family-friendly.

Bennett’s husband, Peter Shelton, is a successful architect, and the family can afford child-care help while Bennett – also an architect by training – pursues her fashion-design aspirations as a finalist on the TV reality show “Project Runway.” But their motives sound similar to those of other, less wealthy parents nationwide who have opted for five or more children.

Dr. Jeff Brown, a pediatrician affiliated with Greenwich Hospital in Connecticut’s wealthy southwestern suburbs, has noticed a clear trend in recent years.

“I don’t hear people say, ‘We’ll have two and then we’re done,’ where I used to hear that before,” he said. “People are much more open to three-children families than they were 10 years ago.”

No population fears

However, really big families remain rare, Brown said, in part because many women are giving birth at older ages – they may not have their third child until in their 40s, when the prospect of a fourth might seem too daunting.

The Census Department says it has no national data specifying which demographic sectors are having more kids these days. But a leading expert on family size, Duke University sociologist Philip Morgan, says it makes sense that some well-off couples are opting for more children as concern about global overcrowding eases because of lowering birth rates overall.

“The population explosion – fears about that are over,” he said. “People used to think that having more than two kids was not only expensive but immoral. Now, people say if you can afford three kids, four kids, that’s great.”

Yet Morgan, who has three children of his own, doubts there will be a boom in extra-large families.

“No matter how much money the parents have, most think each of their kids should have their own place and time,” he said. “More than four – that’s when people start thinking you’re crazy, that you’re shortchanging the ones you already have.”

Bonny Clark, a mother of five from the Minneapolis suburb of Circle Pines, has encountered such skepticism. When pregnant with twins four year ago – with three other children already on hand – even some of her friends were dismayed.

“There were a lot of unwelcome comments, like, ‘If I had three kids and was having twins, I’d kill myself,'” Clark said.

Clark, 38, is aware of the buzz that large families – in the suburbs, at least – are a new status symbol.

“I thought it was kind of funny,” she said “Most people who have a lot of kids don’t have the time or energy to care about what others think.”

Enjoying the challenges

Carmen and Frank Staicer of Virginia Beach, Va., have an even bigger brood – six children aged 2 through 14. The two youngest – including 2-year-old Riley, who is autistic – are at home with Carmen during the day; the others go to local Roman Catholic schools.

Carmen embraces the challenges of raising so large a family but doesn’t minimize them.

“There are many nights I go to bed mentally exhausted, after trying to deal with high school bullies and first-grade spelling words,” she said. “But I can’t think of anything that I’d rather do than be dealing with these incredibly funny, wonderful individuals.”

Even with her husband’s income as a car dealership finance manager, Staicer says budget-balancing can require buying secondhand sports gear and controlling food bills with coupons and leftovers. Each weekday afternoon, she switches into chauffeur mode, driving her children to after-school activities.

“I don’t want them to grow up thinking that because we had all these kids, they couldn’t do anything,” she said.

One gauge of the Staicers’ home life is laundry – 20 loads in an average week. In South Orange, N.J., where Diana and Ronald Baseman have raised 10 children, trash output is the challenge – at one point, garbagemen needed to be tipped before they would haul away the family’s refuse.

The Basemans had six biological children, then – after Diana suffered three miscarriages – adopted four more from Guatemala, the oldest 8 and the youngest barely a year old.

One factor was Diana Baseman’s refusal, as a Roman Catholic, to use artificial birth control, but even as a child she aspired to have a big family.

“I have learned so much from children that I never would have learned otherwise,” she said.