Finding your sperm donor not as easy as in movies

The Donor Sibling Registry reports more than 7,400 matches through the service since its founding in 2000. Nearly 28,000 donors and offspring are registered.

Cairo of CryoGam believes failure is more likely than success in attempts at donor-offspring bonding - another reason she supports donor anonymity. Those who wish to remain anonymous should be able to do so, she said.

"Sometimes these donors are 19 or 20. They don't think that far down the road," she said. "Some might even forget they were a donor in college, and then suddenly there's a person on their doorstep. They're not family. They're genetically linked."

Some are fighting for the United States to require disclosure. The Institute for American Values, a nonprofit group in New York "whose mission is to study and strengthen key American values," released a study called "My Daddy's Name Is Donor," which outlines what it deems the harms of anonymous donation.

The Web-based study of more than 1,600 found that 65 percent of donor offspring agree with the statement "My sperm donor is half of who I am" and that "family relationships for donor offspring are more often characterized by confusion, tension, and loss." The study also found that 53 percent agreed that "It hurts when I hear other people talk about their genealogical background."

Kathleen LaBounty, 28, of Houston, hopes the United States will require disclosure to prevent others from knowing the pain she has felt during a so-far-unsuccessful search for her biological father. After half a decade, 16 DNA tests, and her interviews for The Oprah Winfrey Show and other national shows and publications, her father has not come forward.

"I hope with time he decides to know me," she said. Although she is at peace with the idea that she may never find her father, she hasn't given up her search. "I don't like to live with regrets."