When he was a cash-strapped college student 20 years ago, Todd Whitehurst didn't think too deeply on the consequences of donating sperm.
Then, when he was 41, he got an e-mail from a girl named Virginia. "She said, basically, 'I'm 14, and I think I'm your daughter,' " explained Whitehurst, now a 45-year-old medical engineer.
Shortly after, he found a son, Tyler, now 14. And another, Gavin, now 16. That led to another child, and another, and yet another.
"It was definitely overwhelming," Whitehurst said. "I'm not even sure how many children there are."
So far he has found nine kids sired by his sperm. Statistically speaking, said one biogeneticist, Whitehurst could be the father of 42 to 60 children.
Thanks to a lack of industry regulation, high totals are all too probable, especially for prolific college kids like Whitehurst -- who donated weekly for about three years, for $50 a pop, at a clinic on the Stanford University campus in the 1980s and '90s. A Web site set up for the children of sperm donors has discovered a number of "superdads" who have fathered dozens, sometimes hundreds, of children.
One top seed in Virginia has sired an astounding 129 kids and counting, according to the Donor Sibling Registry, a nonprofit that helps connect families with biological fathers and siblings. Another donor, in the Boston area, has been traced to 72 kids, said Wendy Kramer, a mother to a sperm-donor child who started the online registry when her son began asking questions about his pop.
The registry has found 92 groups of 10 or more offspring, and 336 groups that have up to nine siblings, said Kramer.
There's no limit on how many banks a donor can sell his sperm to -- about 21 percent of donor dads have given to more than one, according to Kramer.
In theory, said Albert Anouna, director of Biogenetics and Sperm Bank of New York, cryo clinics should destroy a donor's sperm after it has produced about 10 live births. Birth numbers are self-reported by pregnant moms -- an incomplete and inconsistent system, Anouna acknowledged.
Compounding the problem, donors are screened so that the most fertile get selected, because high sperm count and good motility are most likely to produce a pregnancy, said Anouna. High-performers who rack up many pregnancies are among the most popular donors selected by women.
"Up until 1999, physicians could order a pool of vials for their patients. They'd come in and the doctor would say, 'This one works fine -- it's already gotten three women pregnant. Why don't you try it?' " said Anouna.
Whitehurst is one of a handful of donor dads to step forward and connect with his kids.
"It was pretty wild," he said of receiving his initial e-mail from Virginia. "She had my donor number, which I hadn't ever given anybody, and she sent a picture. She looked a lot like me."
He e-mailed her back, and Virginia encouraged him to go to the Donor Sibling Registry. His donor number immediately turned up two other families, and later, three more. One of his donor moms actually has three kids from his semen.
A few years ago, Whitehurst, who has two kids from a prior marriage, traveled to meet Virginia, Tyler and Gavin.
Now Tyler and Gavin frequently share e-mails and phone calls with him, and Virginia, about to set off to his alma mater in the fall, seeks dating advice.
Whitehurst can't help but regard his progeny like a typical proud papa -- especially on this day, when the cards and phone calls roll in.