Katrina Clark and Lindsay Greenawalt have much in common. Bright women in their 20s, raised by single mothers, keenly curious about the men whose donated sperm helped give them life.

Clark's search for her father succeeded after only a month, though with a bittersweet aftermath. Greenawalt is still searching, seven years after she started — persisting despite doubts and frustrations.

"I've dreamt of you since I was a little girl," Greenawalt wrote to her unknown dad in a Father's Day blog posting in June. "There are so many things I want to know about you."

Greenawalt, who lives near Cleveland, and Clark, a college student in Washington, D.C., are part of an increasingly outspoken generation of donor offspring. They want to transform the dynamics of sperm donation so the children's interests are given more weight and it becomes easier to learn about their biological fathers.

One specific goal — a ban on anonymous sperm donations — seems far-off in the United States, although Britain and several other European countries have taken that step.

But the voices of donor offspring are being heard more widely and clearly than ever, thanks to Internet-based social networking and other recent developments.

A new film, "The Kids Are All Right," depicts two teenage siblings who track down their sperm-donor father and introduce him to their lesbian moms. Complications ensue, but the teens' yearning to meet their dad is portrayed empathetically.

The film opened just weeks after the release of a provocative study by the Commission on Parenthood's Future, titled "My Daddy's Name is Donor." It surveyed 485 donor offspring, concluded they were more troubled and depression-prone than other young adults in comparison groups, and recommended an end to anonymous sperm donation.

The study's authors said they sought to ignite a debate, and they succeeded — reaction included swirls of pro-and-con blogosphere commentary and op-eds in several major newspapers.

"The adult voices of donor offspring are a welcome counterbalance to an array of cultural forces aimed at further marginalizing fathers," wrote Washington Post columnist Kathleen Parker. "At the very least, as this study implores, it is time for a serious debate on the ethics, meaning and practice of donor conception."

An increasing number of U.S. sperm banks now offer identity-release policies, in which donors agree to let their offspring contact the donor when they turn 18. But many donors still opt for anonymity, producing the kind of frustrations encountered by Lindsay Greenawalt.

A Kent State University graduate who aspires to be a medical librarian, Greenawalt has been searching since 2003 for the biological dad she knows only as "Xytex donor 2035" — the number assigned to him in the 1980s by the Xytex Corp. sperm bank in Augusta, Ga.

She knows the man is now 49, attended college, and — like Lindsay — has brown hair and greenish eyes. She also knows a few medical details, thanks to an update the man recently sent to Xytex after Greenawalt requested it.

But learning of the medical update saddened Greenawalt, because no note came with it.

"He knows I'm looking for him — and he doesn't want to make contact," Greenawalt said, conceding that this gave her doubts about what she'd do if she did manage to identify him.

Her lengthy search has taken a toll in other ways.

"It's been a very sore topic with my mom — she felt it was a personal attack against her, that she hadn't been a good parent," Greenawalt said. "It's none of that. It's something we've got to do that's separate from how we were raised."

Since 2008, Greenawalt, 25, has been chronicling her quest on a blog, "Confessions of a Cryokid." One of the most wrenching entries came last Thanksgiving, when she addressed the oft-repeated refrain that donor-conceived children ought to be grateful they were born.

"If I had to choose between being conceived with half of my identity and half of my kinship deliberately denied from me for eternity — or never being born — I'd choose never being born," she wrote. "We were created to carry a loss. A loss that no human being should have to endure."

The plight of donor offspring like Greenawalt deeply touches Katrina Clark, who surprised herself in 2006 by discovering the identity of her father on the Internet after a few weeks' research. She sent him an e-mail and got a prompt, friendly reply, with a photograph included.

Since then, however, "our communication has been pretty much nonexistent" and they have not met face-to-face, said Clark, a 21-year-old student at Gallaudet University who admits to being frustrated by the impasse.

"Maybe I pushed or pulled too much," Clark said. "He wasn't ready to be out in the open about it. ... Perhaps he was embarrassed or ashamed.

"I still wonder about him," she added. "There's so much about him I still don't know."

At one point, Clark soured on the entire idea of donor conception. Now she accepts that it can be a blessing for some families, but she favors ending donor anonymity and hopes more parents will tell the truth early on to their donor-conceived children.

"The most damaging thing I've seen is when parents wait to tell," she said.

In an article she wrote for The Washington Post in 2006, Clark described the emotions that wracked her as an adolescent.

"I realized that I am, in a sense, a freak," she wrote. "I finally understood what it meant to be donor-conceived, and I hated it."

She evolved into a dedicated activist, even lobbying for an unsuccessful bill that would have made Virginia the first state to ban anonymous sperm donations.

The American Society for Reproductive Medicine, which represents many sperm banks and fertility clinics, encourages parents of donor-conceived offspring to tell their children the truth about their conception.

But it does not favor banning anonymous donations, saying the children's rights must be balanced against the interests of donors and the parents who will raise the child.

"The bottom line in the U.S. — we've always been big proponents of individual rights in regard to procreation," said Andrea Braverman, who serves on the ASRM's ethics committee. "We've always taken the approach that we get our own choices in terms of how we build and manage our families."

Parents who want to ensure their sperm-donor offspring can learn the identity of their biological father can arrange that when they select a donor, Braverman said.

A past president of the Society for Assisted Reproductive Technologies, Dr. Jamie Grifo of New York University's Fertility Center, said heavy emphasis on the rights of a child wouldn't always work in the realm of donor-assisted conception.

"It may not be a popular point of view, but when these decisions are made by donor and a parent, the child doesn't have a say," he said. "If the contract is for it to be anonymous, it should remain anonymous, and the child just has to deal with that."

Grifo believes that many donor offspring who do track down their biological fathers end up unfulfilled.

"They take this on as a quest to solve all their issues, the stuff we all go through in adolescence," he said. "Some of the reunions are good. Many are a huge disappointment."

The "good" category would include the remarkable story of Todd Whitehurst, now a 44-year-old physician in New York City, who donated sperm to a California sperm bank while a graduate student at Stanford University.

One of the children conceived with his sperm tracked him down in 2007, using MySpace. Whitehurst soon met with that girl, who is now 17, and two half brothers, now 12 and 15, all three of them raised separately by single mothers who'd used the same sperm bank.

This suddenly connected clan has gotten along so well that they keep in steady contact and have even taken vacations together, to a Pennsylvania resort, to Tennessee and to Disney World.

"It's been much better than I ever imagined," Whitehurst said. "The kids never expected anything from me — they just wanted to get to know me, so we've chosen to spend more time together. It's viewed as a bonus, an extra great thing that happened in our lives."

"I'm really lucky, because all three have turned out to be nice, smart kids," Whitehurst added. "Of course, I may be biased."

One of the mothers, Cheryl Shuler of Butler, Pa., said meeting Whitehurst has been a wonderful experience for her 15-year-old son.

"Gavin always was very accepting of being donor-conceived and, if he had never met his father, I don't think he would have been pining away for him," Shuler wrote in an e-mail. "But it was fulfilling for him to meet, not only his dad, but the rest of Todd's family as well."

Among the bonuses, Shuler wrote, was that Gavin now can observe a second source of his identity, reflecting the pronounced personality differences of his two biological parents.

"Todd is a city person and I am very small town. ... Todd is a night owl and I am in bed by 10 p.m.," Shuler explained. "I am glad that Gavin is getting to see two different sides."

Another notable saga has unfolded in Australia, where Myfanwy Walker met her donor dad, Michael Linden, in 2001 after a determined search that included going public in a newspaper article. He read the article, contacted her, and they've remained friends ever since despite various challenges for their families.

Walker, now 29 with a husband and infant son, was told by her mother at 20 that the dad who raised her had been infertile and that she was a sperm-donor offspring. Walker's parents had recently divorced; the revelation added to the trauma.

"When your sense of identity and self is obliterated like that, it helps to feel you can control at least some aspects of your life," Walker said. "Searching for my father was my way of feeling like I was taking control."

Finally meeting Linden, and his wife, was intense — lots of questions and catching up.

"All of it was so strange, abnormal and upside-down," Walker said. "Michael was a stranger to me but at the same time I felt I'd known him my whole life."

Though grateful they connected, Walker and Linden have publicly criticized donor conception, saying it too often impinges on the rights of the children it produces.

At one forum, Linden described himself and other sperm donors as "unwitting perpetrators of what I believe is an immense and tragic denial of the human rights of our children to know their true identity."

In the U.S., sperm donation is a huge business, though no official statistics are compiled. Some experts estimate there are at least 30,000 sperm-donor conceptions annually — perhaps many more.

More than 28,000 people involved in anonymous donations — offspring, parents and donors — have registered with the Donor Sibling Registry, a Web-based network run out of Colorado by Wendy Kramer.

She started the registry so her donor-offspring son, Ryan, could find his siblings, and she says it has helped more than 7,400 people find half-siblings and biological fathers.

Kramer is part of an international network lobbying to end anonymous sperm donations and improve record-keeping so that tracking becomes easier.

"It's always the rights of the parents, the donor, the clinic," she said. "Why is it that the rights of donor-conceived people aren't even considered in the equation?"



Donor Sibling Registry: http://www.donorsiblingregistry.com

American Society of Reproductive Medicine: http://www.asrm.org

My Daddy's Name is Donor: http://www.familyscholars.org/assets/Donor_FINAL.pdf