Hit or MissJumping on a hot trend at just the right time can be a great way to launch a business. But how can you tell if a trend has enough staying power to stake your startup on it?

Three years ago, Rebecca Cutler and Jennifer Krane saw bigchanges happening in the athletic wear and maternity industries.Women were wearing athletic clothes for going out, not just workingout. Obstetricians were encouraging pregnant women to keep up amodified exercise regimen to stay fit, whether it be yoga, walkingor another favorite sport. Designers were creating fashionableclothing lines for pregnant women, and celebrities were makingpregnancy look hip, beautiful, fashionable, even athletic. Cutlerand Krane did some research and learned that 4 million babies areborn every year in the United States, and American women spend anestimated $1.2 billion annually on maternity wear.

There was a pregnant pause, however, when they compared whatthey saw to what was on the racks at sporting and maternitystores-especially when it came to tennis, a sport Cutler and Kraneboth love. "[Pregnant women] were buying extra-largenonmaternity tennis skirts-pulling them on, feeling awful and notreally fitting into them," says Cutler, a mother of two. Theythought a box set of fashionable maternity athletic clothes thatincluded a mix-and-match reversible tennis skirt, a few V-neckshirts, and shorts that could transition from the tennis court to anight on the town just might sell.