It's not just in your head. There really is a bumper crop of baby bumps out there, from the famously fertile, like Heidi Klum, who's flirting with her fourth set of stretch marks in five years, to the infamous Nadya "Octomom" Suleman, who earlier this year bore eight babies at once even though she already had six other kids at home that she could barely afford to take care of.

In 2007 alone, American women birthed more than 4.3 million babies — the highest number ever. More than a quarter of those were to women having their third or fourth child, according to the Centers for Disease Control and Prevention. And despite the infertility freak-out the entire country seems to be currently engaged in, only a small number of these babies — perhaps 100,000 — resulted from medical interventions such as in vitro fertilization, says Jamie Grifo, M.D., Ph.D., director of the division of reproductive endocrinology at the NYU School of Medicine.

That doesn't mean that we're transforming into a nation of Duggars (the Arkansas family with 18 kids often seen announcing their latest conception on NBC's TODAY show) and Novogratzes (the New York City clan of seven kids soon to be the focus of a new Bravo reality show) — the average number of children per American family is still hovering right around two.

Still, certain mothers, like 31-year-old Meagan Francis, who is raising her flock of five in Michigan, have big broods because that's what they're used to. "I grew up in a relatively large family and always loved having lots of people around," she says. "So it's natural that I'd try to re-create that experience with my own family."

But it's not always quite so simple, psychologists say. Some women may like being pregnant a little too much, often driven to rapidly reproduce out of insecurity, a craving for attention, or feelings of abandonment by their own parents.

The high of pregnancy



Having babies isn't addictive in the way that alcohol and narcotics can be. But bumpaholics feel compelled to procreate for many of the same reasons that substance abusers turn to booze or drugs.

"Women who are obsessed with being pregnant are literally filling an emptiness inside of them, just as alcoholics and drug addicts use substances to fill a psychological void," says Beverly Hills psychiatrist Carole Lieberman, M.D. Every one of us at some point encounters this void, adds New York family therapist Bonnie Eaker Weil, Ph.D., author of "Financial Infidelity." "You want to have a purpose in this world. You want to feel less lonely."







For some women, babies fill that gap perfectly. Infants are dependent creatures. They can give their mothers a clear identity; they can also become handy social buffers. At a party or on the playground, a woman struggling with feelings of social anxiety or self-consciousness can hide behind the adorable infant in her arms. Any pressure to be cute or charming or funny disappears — your baby has that covered. "Bumpaholics breed to blot out their feelings of insecurity," Weil says.

Boston psychiatrist and Fox News consultant Keith Ablow, M.D., says some women seem to view having more children as an alternative to addressing their own personal problems. "Bearing another child can sometimes provide a substitute for deciding on a career path, making a marriage work, or even wrestling with questions of self-worth," Ablow says.

And the baby fix can become a cycle. When an infant becomes a more independent toddler, "the mom may feel abandoned and act quickly to fill the void again with a new baby who will rely upon her and her partner and define their lives," Lieberman says.

Procreating isn't just a psychological balm; it also feeds genuine physical cravings. According to Helen Fisher, Ph.D., a professor of anthropology at Rutgers University, humans developed a set of three related brain systems that are intended to push them toward parenthood: sex drive, hunger for the romantic love of one partner, and a desire for the calmness and security of attachment.

Mother Nature prods us by making sex and its aftermath feel amazing. Oxytocin, the so-called "cuddle" hormone that promotes bonding, floods women's bodies during intercourse, pregnancy, childbirth, and breastfeeding. "[Pregnancy] is like a love drug," Weil says. "A baby-love drug."









Then there's the constant attention you garner from others when you're bursting with child. Bumpaholic or not, it can be pretty great. Barb Pomeroy, 42, of Longmont, Colo., is a mother of six girls. She admits that she reveled in the questions and comments her pregnancies elicited from family, friends, and even complete strangers. She also loved the compliments people fed her about how good she looked when she was pregnant with her daughters. Even though she's not planning to have any more children, she misses the heightened interest and confidence pregnancy often brings. "There's this feeling of being special when you're pregnant," she says. "I feel like I become ordinary again when I'm not expecting."

It's not hard to understand why: People smile at you, throw you baby showers, buy you lots of gifts. And the rounder your belly gets, the more space you take up in the world, and the more people take notice of you. In many respects, you become impossible to ignore.

Spouses and partners dote on you, gladly delivering soup at 10 a.m. or antacids at 11 p.m. "My husband constantly rubbed and coddled me, and I ate it all up," says Liz Bustamante, a 39-year-old financial advisor from Forest Hills, N.Y., who has one child and is currently planning for the next. "And for the first time in my life, instead of feeling insecure about my body, I wanted to run around naked! I'd never felt sexier."

Magazines conduct celebrity-bump watches, and nude maternity portraits are becoming de rigueur for celebs and civilians alike. Pregnancy lets every woman be a star in her own world, and the rest of us are all too happy to shine the spotlight. A pregnant woman is exciting because the child she's carrying represents "that tie to the future," says Holly Donahue Singh, a Ph.D. candidate in anthropology at the University of Virginia who teaches a class called Anthropology and Reproduction: Fertility and the Future.

Filling a void?



The belly-rubbing high hits the pregnant woman as well as the people who surround her. The expectant mother gets an oxytocin blast and rubs her belly as a way of bonding. Admirers who rub her belly get a hormone rush, too. "As social creatures, our brains have evolved to make positive social behaviors feel good. Touch causes the release of oxytocin, and this causes the release of dopamine in reward regions of the brain," says Paul J. Zak, director of the Center for Neuroeconomics Studies at Claremont Graduate University.

Given all the psychological, physical, and social rewards associated with pregnancy, it's no surprise that so many women like it. But plenty of couples stop at one or two children, despite the fundamental drive to reproduce. This is because we can use our higher brain functions to keep those instincts in check, reminding ourselves that children cost money — about $950 a month until they're 18 — and require an extraordinary amount of time and energy.

This is precisely why the bump-loving Bustamante says she'll stop at two. Much as she loved her pregnant body and adores being a mom, she wants to allow for some financial flexibility — childcare, ballet lessons, summer camp, and college tuition add up. Having sufficient funds isn't a deal-breaker for everyone, though. Nan Mooney, a 39-year-old single mom, is living with her parents in their Seattle home because she doesn't make enough money to support herself and her son. Still, she desperately wants more kids. Her friends and family call her crazy, she says, but "I knew enough people growing up who had plenty of money who were not necessarily loved and not necessarily happy. I don't think it's an essential ingredient to raising well-adjusted children."

Figuring out the right number of kids to have is a personal decision, to be sure. And not all women with lots of children are bumpaholics. But an important question for pregnancy-craving mothers to ask themselves is why they want more children, Weil says. Are you having them because you don't want to deal with your husband? Or so you don't have to go back to work? Or because you love the attention? Nadya Suleman, for one, is blunt about the fact that she got pregnant to fulfill an emotional need. As she reportedly told one journalist, "I just longed for certain attachments with another person that I really lacked."

But psychologists say there are far better ways of making meaningful connections. In order to have a healthy relationship, married moms need to spend quality time alone with their husbands — whether it's taking a vacation without the baby or just going out to dinner together once a week and leaving the kids with a sitter. "Women who focus on their children to the exclusion of everything else inevitably face an emptiness when their kids grow up and become more independent," Weil says.

If you do find yourself feeling a void as your bundle of joy becomes a toddler, "that's a good sign that it's time to look in the mirror and figure out what's going on with you," says Ann Pleshette Murphy, author of "The Seven Stages of Motherhood: Loving Your Life Without Losing Your Mind." "Invest in yourself. Though it may never be as satisfying as what we get from taking care of our kids, it's important to feel proud of something you do outside of child-rearing so that you don't think of yourself as 'only a mom.'"

"Me time" can include big things — like going back to work or starting your own business from home — or small, daily experiences that enrich your life, such as heading to the gym or joining your girlfriends for dinner and cocktails. It's only when you have a balanced life that you can be sure the inner call for a new addition to your family should be answered.