For the first several months of my pregnancy, I didn’t give much thought to caring for my stretching skin. I was too busy worrying about what I was putting in my body to worry about what I was putting on it. But in my fifth month, I started thinking about stretch marks — the bane of somewhere between 50% and 90% percent of pregnant women — and decided it was time to get serious about skin care for my ballooning belly.

I’m not alone. While market research firms like Euromonitor International and NPD Beauty don’t follow the pregnancy skin care market, anecdotal evidence seems to indicate that expectant moms are helping the category grow.

The pregnancy beauty company Mama Mio launched Tummy Rub Stretch Mark Oil ($30) last year and added Tummy Rub Stretch Mark Cream ($30) in April. The company’s founder and managing director, Sian Sutherland, said her company’s sales of prevention products are growing at a rate of 50% a year.

At Destination Maternity stores, 18 different brands of pregnancy skin care, including Mama Mio, are available. Mustela’s Double Action Stretchmark Cream ($34.50) is a top seller. “Our skin care division continues to be a growing category for us,” Destination Maternity’s president and creative director, Rebecca Matthias, said. “We have monthly recaps of our total sales, and skin care continues to grow.” Much of the growth comes from new lines, with as many as three to five being added each year, according to Ms. Matthias.

Destination Maternity’s in-store maternity spa, Edamame, offers a $115 anti-stretch mark treatment called the Redefine Organic Nutritional Body Mask. At the New York City location on Madison Avenue, it’s among the spa’s most popular treatments, the spa’s manager, Holly Grunsell, said.

Ms. Sutherland attributes the growth to a shift in attitude toward pregnancy. “The maternity skin care market is growing rapidly as women realize that they don’t have to give up just because they are pregnant,” she said. “They want to look after themselves. And the whole celebrity baby boom has certainly made it more difficult to ‘let yourself go’ just because you are a mum now.”

As a result, there seems to be a lotion, cream, or oil, touting ingredients such as essential fatty acids and Vitamin E, for every belly and budget. There are even products designed to be used after pregnancy. But can a cream really prevent stretch marks in the first place?

Some experts — including my obstetrician and two dermatologists I spoke with, an assistant clinical professor at Mount Sinai School of Medicine, Dr. Debra Jaliman, and a clinical assistant professor in the department of dermatology at New York University Medical Center, Dr. Ariel Ostad — are skeptical.

In an e-mail message, Dr. Jaliman said she feels there is no truth to the claims that products on the market today prevent stretch marks.”Stretch marks are caused by the breakdown of elastic tissue,” she said. “They result from rapid weight gain.” (That’s hard to avoid when you’re pregnant, in my experience.) The experts said that while genetics may also play a role, keeping weight gain in a healthy range and exercising can help prevent stretch marks. Dr. Ostad stressed, however, that dieting during pregnancy is not a healthy stretch mark preventing solution.

That’s not to say there’s no reason to use a stretch-mark preventing product. Dr. Ostad said that while moisturizing “is really not a treatment to avoid stretch marks,” it can help keep skin’s collagen layers supple. He also concedes that the essential fatty acids in many products “may help.” And massaging a rich cream or oil can simply feel good on a swollen belly. One Brooklyn mother, Poppy O’Neill, said she enjoyed using Mother’s Special Blend skin toning oil ($11.99 at drugstore.com). “I liked that it felt good, and, because it contained cocoa butter, it smelled a little bit like chocolate,” she said.

Cecilia Phillips, who lived in Manhattan during her first pregnancy, tried three different pregnancy skincare products before finding one that she liked. The first contained chemical ingredients that “scared” her. The second boasted all natural ingredients, but gave her a rash. Her final choice: Beautiful Belly Balm by WiseWays Herbals ($17.60 at wiseways.com). “It has been wonderful,” she said. “No chemicals, no itch, [and] not one stretch mark in my belly.”

Dr. Jaliman said that Ms. Phillips” fear over chemical ingredients was likely unfounded, saying that most chemicals included in these products are not absorbed in the bloodstream. My doctor warned me against using any skin-care product that contained Retin-A or retinol, however, and pregnant women should check with their doctors before using any product. Some skin-care experts also caution against the use of certain essential oils. “We spent over a year reviewing essential oils to determine which would be best for our line,” the co-founder of Basq Skin Care, which launched Resilient Belly Oil in March 2005, Lauren Parisier, said. “We chose to avoid any oil that had been questioned for safety [during pregnancy], using the opinions of experts in the medical and aromatherapy fields, as well as the Basq team.”

As for me, I used a handful of different products, including Palmer’s Cocoa Butter Formula Moisture Enriched Lotion with Vitamin E ($4.49 at drugstore.com), and both Mama Mio’s and Basq’s oils. I finished my pregnancy stretch-mark-free, although that may be due more to luck than lube: I delivered three weeks early. But if there’s another pregnancy in my future, these products will be in my beauty arsenal. After all, when it comes to skin care, a little extra babying never hurts.