Initial public offerings capture all of our imaginations. Even in the lackluster past year, you could find lots of news coverage about IPOs in numerous industries. The realm of health care was no exception. So let's look back at four of the most intriguing IPOs from 2007 in the health-care field.

Research on the cheap
As if its being Chinese wasn't exciting enough, WuXi PharmaTech (NYSE:WX) made its U.S. debut in August and hasn't looked back, with shares more than doubling since then.

The company is an outsourcing operation for the biotech and pharmaceutical industries. It conducts research at almost all levels of drug development -- from screening a library of compounds for biological activity to manufacturing drugs for initial research-and-development studies. It's certainly a well-respected company in the industry: Last year, it had nine of the 10 largest drug companies as customers.

WuXi has reported only one quarter's worth of earnings since it went public, but what a stellar quarter it was, with 78% year-over-year revenue growth.

Can WuXi keep up 78% growth? I don't know, but my guess is that the trend of outsourcing isn't going to reverse itself. As companies such as Johnson & Johnson (NYSE:JNJ) and Amgen (NASDAQ:AMGN) cut back on their costs, outsourcing is going to play a bigger role in drug development than it ever has in the past.

A bloody good company
Having nearly doubled since its October IPO, Genoptix (NASDAQ:GXDX) is a company that investors clearly love. What's not to like about the 152% year-over-year increase in revenue that it posted for the first nine months of the year?

Genoptix provides diagnostic services to community-based hematologists and oncologists treating diseases and cancers of blood and bone marrow. However, since there are only so many hematologists and oncologists to go around, I have trouble seeing the company continuing to grow indefinitely without expanding its offerings to other specialties. Even Genoptix itself expects things to slow down a little bit -- but still, the outlook doesn't seem all that bad. Annualized revenue growth is forecast to come in at just 50% next year. In any event, there's no question that the company does have growth potential for the immediate future.

Not a total flop
Although it wasn't a ringing success, Jazz Pharmaceuticals' (NASDAQ:JAZZ) mediocre IPO isn't such a bad choice for the list, especially given the myriad health-care IPOs this year that have been total flops. Its stock price has fallen about 17% since the IPO, but it looks as though Jazz's second year as a public company will be better than its first, thanks to an approvable letter the company received last week for Once-A-Day Luvox CR.

Jazz and partner Solvay Pharmaceuticals are trying to get the drug approved for the treatment of social anxiety disorder and obsessive-compulsive disorder. The companies previously got an approvable letter in February and appear to have taken care of two of the three issues the FDA had at that point. The third concern, having to do with release specifications and expiration dates for the product, could be wrapped up shortly. Since the agency didn't have a problem with the safety or efficacy of the drug, and since it has already proposed labeling information, the drug could be on course for a launch in the first quarter of 2008.

The one that never made it
Adnexus Therapeutics had filed papers with the SEC for an IPO that would have raised $86 million for the company, but the offering never happened. Instead, a month later, Bristol-Myers Squibb (NYSE:BMY) announced its plans to buy Adnexus for $430 million in cash.

That was a pretty large sum of cash for a biotech that had just one phase 1 drug, but Bristol is banking on Adnexus' ability to develop more protein-based drug candidates using its PROfusion drug-discovery system.

Bristol's purchase may be a sign of things to come. As pharmas' appetites for biotechnology grows, we may see more privately held companies getting snatched up before they even have a chance to make a public offering.

While IPOs are fun to watch, I'm not one for jumping into IPOs just because they're exciting. Sure, you miss the boat on the WuXis of the world, but you and your money also don't get caught up in all the hoopla of the many flops. Take your time, and do your due diligence. If the companies are worth investing in, there will still be plenty of time to invest in them.

More Foolishness on new public companies:

As Foolanthropy enters its second decade, join us in working to bring financial education to the world's children. Learn more about Foolanthropy's new direction.

Want to know the latest drug stock that's joined the ranks of our Rule Breakers growth-stock newsletter service? Take a look to take a look all of our recommendations -- drug stocks and otherwise -- with a free 30-day trial.

Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Johnson & Johnson is a selection of the Income Investor newsletter service. The Fool has a disclosure policy.