Sperm donations have resulted in the births of an estimated 1 million children.

Since the first commercial sperm bank opened in the early '70s, it's estimated that more than a million sons and daughters have been conceived using donated sperm. As these children grow into adults, many are starting to ask questions and search for answers.

This 21st-century family drama is affecting everyone involved, including the parents who depended on donated sperm and donor dads who never imagined meeting their biological offspring.

Many sperm donors are now faced with an important decision...should they meet the children they helped create?

Every year, thousands of men visit sperm banks across the country to donate sperm. Some choose to donate for financial reasons, while others are hoping to help single mothers and infertile couples become parents.

Matthew, a pediatrician from Michigan, says he first donated sperm at the suggestion of a patient's parent. "I was in a long distance relationship at the time, so I sure wasn't using it," he says. For the next four or five years, he says he donated several times a month.

"My initial motives for being a donor are the same kinds of motives that somebody has when they donate blood or sign up on a marrow registry or sign their organ donor card on their driver's license," he says. "It says, 'If I'm not using it, and it's useful to somebody else you know, that's a good thing.'"

After years of donating sperm, Matthew decided to start a family of his own. In 2006, he and his wife welcomed a little girl, Arwyn, into the world.

Though he only considers himself a father of one, he knows of five other boys and girls conceived with his donations...but there may be more. His sperm bank says he could be the biological father of as many as nine children.

"I've received photos of the children conceived with my donations," he says. "I don't look at them and think of them in any shape or form as my children. I mean, these are children who have families."

As a pediatrician, Matthew says he tries his best to involve young children when making decisions about their future. "My disposition toward these children and the families that have contacted me is one of availability, but in a very passive way. I don't want to insert myself into their lives," he says. "I think it's really hard to predict whether or not a donor-conceived child would want a donor in their life. ... It would be my preference that if there's any kind of relationship that would evolve with them, which I'm receptive to, that would be at the initiation of the child."
Mary chose to use Matthew's sperm to have a child.

Every potential parent who visits a sperm bank has different criteria for the perfect donor dad—height, weight, hair color, IQ.

When Mary was given a stack of donor profiles to sort through, she says Matthew's stood out from the rest. Though privacy concerns prevented her from seeing more than half of his face in a photograph, she chose him to be her unborn child's biological father. "He was a pediatrician. He had very diverse interests, which made me think that he [used his] left brain and right brain," she says. "I just thought that was a wise choice."

Mary got pregnant using Matthew's sperm. Now, she's the mom of a 2-year-old daughter, Alexandra. When the time is right, Mary says she plans on telling her daughter the truth about her birth. "I don't want to keep any secrets from her because I just don't believe in it," she says. "She doesn't ask me too many questions yet. ... Right now, she's living in a perfect world. I love her, and she's loved by a lot of people, so she's not missing anything."

Todd—also known as sperm donor #2053—was working toward his PhD at Stanford University when he decided to donate for the first time.

"There were the newspapers on campus always running ads that were trying to recruit for sperm donors," he says. "I was a poor graduate student. So it always crossed my mind that it might be a good way to supplement my income and to kind of help people out, as well."

When Todd first visited his local sperm bank, he says they were offering men $35 or $40 per donation. Over the next four years, he says he donated sperm up to three times a week. "It really became part of my routine," he says. "I'd wake up, go to class, do some research, and then around lunch time or right after lunch, I'd donate, which doesn't take very long. Then, [I'd] go right back to class."

Todd says over four years he earned $16,000 for his donations
Todd and Oprah

Many donors choose to remain anonymous, but Todd has decided to be a part of his biological children's lives. Since registering on the Donor Sibling Registry, a website that helps children conceived by sperm donations find their half siblings and biological fathers, Todd has met three of his offspring, though he says he could have as many as 10 children.

"When we first got together and met each other, we went to the museum, went to dinner and went to Disneyland," he says. "I bought them all presents for their birthdays. I bought them all presents for Christmas, as well. I also got several Father's Day cards."

Since meeting his children, Todd says his life has become richer. "It's really been wonderful to get to know these kids," he says. "I love them, and I really feel like we're developing a really close family connection."
Cheryl chose to use Todd's sperm to have a child.

Almost 13 years ago, Cheryl chose to use Todd's donated sperm to have a child. "I desperately wanted a baby, and I was hearing my biological clock ticking," she says. "I wasn't in a relationship that I thought was going to lead to that, and I felt like an anonymous sperm donor would not be a legal hassle for me."

For many years, Cheryl raised her son, Gavin, without a father figure. Then, less than a year ago, they connected with Todd. Since that day, Todd says he's seen Gavin several times. "I've been out to the house," he says. "We go on vacations together."

Unlike many donor-conceived children who never learn their father's true identity, Gavin now has someone to call Dad.

"It's been wonderful for my son," Cheryl says. "This has just totally enriched our lives. ... We are definitely a family."

 For many donor-conceived children, not knowing who their biological father is has led to many mixed emotions.

Kathleen learned she was a donor-conceived child when she was 8 years old. "My mom sat on my bed upstairs, and she just said that, 'Your dad is still your dad on your birth certificate, but I had to go to a sperm bank to conceive you,'" Kathleen says.

Now 26, Kathleen says having no information about the donor's medical history, heritage or family has been frustrating. She isn't even sure if her donor father knows she exists. "To me, it feels like the death of my biological father and half of my family. I've been searching, and I can't find them."

Kathleen's search has centered on the few facts she knows about her donor dad—he was enrolled in medical school at Baylor College in 1981. Over the years, she's written 600 letters to men who fit that description and received 220 responses. Despite 15 DNA tests in one year, she still doesn't have any answers.

Over the years, Kathleen says her feelings about not knowing her biological father have changed. "When I was younger, it was more of the curiosity, like why am I who I am and what did I get from my biological father? How am I like him? How am I different from him?'" Kathleen says. "Then as I got older, it became more grief and more anger, and I just feel like it should be my right to know who this man is."

Finding the donor, Kathleen says, would make a big difference in her life. "I feel like it would put the pieces of my life together and it would provide information about who I am that many people just take for granted."

Susan grew up thinking she knew both of her biological parents. But when she was 27 years old, her mother told her the secret she had kept since 1967. "I felt lied to. It seemed like a big secret. It was hard for me to imagine why you would keep something like that secret for so long." Susan says it had never crossed her mind that she might not be related to one of her parents. "I happen to look a lot like my mother, and it absolutely never occurred to me," she says.

Susan says her mother had several reasons for waiting 27 years to tell her daughter the truth. "At the time I was conceived, the doctor specifically told my parents not to tell me and not to tell anyone, to pretend that this had never happened," she says. The father she grew up with was also a consideration. "My father was very ashamed of his inability to have children at that time. It was very hard for him, and he just didn't want anyone to know, and my mother respected that and kept the secret."

After years of silence, Susan says her mother chose what she thought was the right time to tell her daughter the truth. "My father and I were no longer in contact. My parents had gotten divorced," Susan says. "A little late, in my opinion, but she felt like it was the right time."

At age 39, Susan says she would like to meet her biological father. But because she was conceived in 1967, before sperm banks were common, she says it would be very hard to find him. "My mother was told that they were using a dark, eastern European donor that would match my father so it would be easier to pretend," she says. "That's all I know."

Nineteen-year-old Katrina has known for her entire life that she is a donor-conceived child. "My mom has always been very open and honest with me," she says. "It totally lessens the amount of secrecy involved, so there's less pain in the process of finding out who I am."

Although she knew the truth about her biological father growing up, Katrina says it hurt to see her friends with their fathers. "I didn't understand why I couldn't have a relationship like that," she says. "Even when I approached my mother, she couldn't say anything. It's already been done. I've been born. It was more a sense of loss, a sense of grief." At times, Katrina says she also felt angry. "I felt that I was a product. I am a product of an industry," she says. "It kind of dehumanizes everything."

Katrina began a search for the donor in order to learn the answers to some important questions. "What is my complete medical history? Does he have an interest in music? Where does he live? Does he have any kids of his own? Does he ever think about me?" she says. "I just wanted to know anything and everything I could."

Katrina's efforts paid off, and she found her biological father. She says she wants to have a relationship with him, but that hasn't really happened. "Just basically e-mails back and forth," she says.

When Christina's mother decided to conceive using donated sperm, she had a specific kind of man in mind. "My mom decided to use African-American sperm because she's actually a white woman, and she wanted her children to match, and [my siblings'] fathers are both black," Christina says.

Although Christina always knew how she was conceived, she says something was missing from her life. "This education, this medical background, this knowledge, these looks, you know?" she says. "I wanted to know the black side of me. I just wanted answers." Growing up, Christina says she always looked forward to finding out more about her biological father. "I knew when I turned 18 that I was allowed to meet him," she says.

When she was old enough, Christina finally learned her biological father's name—Phillip. Eager to end her yearslong wait, she made a phone call that would change her life. "When I first called him, I was absolutely nervous. I was shaking," she says. "I gave him my number if he wanted to call back, and he did."

In a marathon conversation lasting four to five hours, Phillip and Christina shared everything about their lives—from where Phillip grew up to their shared sense of humor. "I was able to dip into this bucket of information to find out all the answers that I was looking for," she says.

Since that first phone call, Christina, who is now 22, and Phillip have forged a relationship that Christina says has enriched her life. "I call him Dad," she says. "He's like my second dad."
Christina and Phillip

When Christina contacted Phillip, he was the father of young twins. Now that his children are 13, what do they think about the situation? "That's a work in progress," Phillip says.

In the years since he donated sperm, Phillip says he occasionally would think about the children he might have helped to conceive. "But then your life just goes forward. You keep doing things," he says. "When [Christina] called and we talked, right from the start everything just came flooding to me. When we first met, it was awe-inspiring."

Now that they have known each other a few years, Phillip says he does feel in many ways like a father to Christina. "In a sense I do because of the things that we have in common, which are just incredible, just the things that we talk about in the flow," he says. "As far as cracking the whip or anything, [I do] nothing like that. I know she has a real dad. But if she calls me for advice, I give her advice. First I say, 'What did your dad say? What did your mom say? Now I can give you advice.'"

In all, Phillip says his sperm donations resulted in the births of seven children. Besides Christina, only one other child has contacted him. "We talked about five minutes, and then he said, 'Call me back.' I called him back, and then he never returned the call," Phillip says. "I'm not going to interject myself into his life. If he wants to talk to me, hey, he can call."
Nicole and Matthew

Reactions from family members of sperm donors can vary greatly when donor-conceived children come into their lives. While Phillip's family struggled to make the adjustment, Matthew's wife Nicole says she was happy when Matthew heard from the mothers of his biological children.

"When they first contacted us—well, contacted Matthew—I was pregnant with our child, and that was hard. It took us several years for us to conceive, so I think it would have been harder had I not been able to conceive," she says. "But [since we were] carrying our own child, we were just so happy, and I was so proud of him."

As a pediatrician, Nicole understands why donor-conceived children would want contact with their biological fathers. "I care about kids, and I know kids have questions," she says. "I can understand the need to get to know Matthew, and I think that would be great, because I think he's great, obviously."

Throughout his life, Chris has only known his father by one name...#46. As the only child of a single mom, he learned he was the offspring of a sperm donor early on.

"I knew that I was conceived differently from a very early age," he says. "But I've always felt very loved."

Becky, Chris's mom, taught her son to embrace his history. "I said, "You know what Chris, a man donated his sperm, and you are a gift. This man already has a family, and he gave the gift of life. You are a love child.'"

Little did Chris know, Stacy, a woman who lived less than 30 miles away, also grew up knowing very little about the man her mom chose from the sperm bank.

When Stacy was in middle school, she says she had a hard time explaining where her father was to other kids. "So I just told them that my dad was not around," she says. In reality, Stacy didn't know much about the man who donated the sperm used in her conception.

Kim, Stacy's mom, says her daughter always yearned for a larger family. "She's an only child. ... I think she would have liked to have had siblings when she was growing up," she says. "She's grown up wondering about that other side of her family."

As she got older, Stacy's curiosity about her biological father grew stronger. She logged onto the Donor Sibling Registry to search for more information, but instead, she discovered Chris. She immediately noticed their mothers went to the same fertility clinic. After seeing his photo, she began thinking they might have a lot more in common.

"The chin and even the nose, especially the eyes...that's the first thing I noticed," she says. "We really have the same eyes. I felt like I was looking at a version of myself, but I didn't want to get my hopes up too high until I knew for sure."

Further research revealed that she and Chris had both lived in Paris during college and were fluent in French. "I was just like, 'This can't be just a coincidence!'" she says.

Stacy asked her mother for her biological dad's donor number—46. She then e-mailed Chris with the news. After discovering he had a half sister, Chris says he jumped around yelling, "Is it possible that I have a sister? I can't believe this is possible!"
Stacy and Chris

 After three months of daily e-mails, Chris and Stacy finally get to meet face-to-face in Seattle.

Chris boards a train in Portland, Oregon, and begins the short journey to see his half sister. "I'm looking forward to hugging her and listening to her and sharing with her," he says. "I feel like my life is about to get quite a bit richer. I'll always have someone to call, someone to cry on their shoulder. That's a pretty rare thing, especially when you've grown up as an only child."

On her way to the train station, Stacy says she's so excited, she gets goose bumps. Around her neck, she wears a scarf Chris sent her for her birthday.

Watch Chris and Stacy's emotional meeting.Watch

Finally, the brother and sister meet for the very first time. They stare at each other with the same pair of green eyes. "This is really bizarre," Stacy says. "Are you sure that we're not twins?"
Chris and Stacy

Though these long-lost siblings have yet to find their father, donor #46, Stacy says she's made peace with it. "Actually meeting Chris has made that kind of okay with me," she says. "It seems like we've been talking about this void that occurs inside of you when you're conceived this way, and you find different ways to fill it. For me, finding Chris has kind of filled that void."

Growing up, Chris says he didn't realize something was missing from his life. "I think if there was a void, there were many wonderful ways to fill that void, [which] bore wonderful fruits," he says.

When Stacy and Chris connected, he was volunteering with the Peace Corps in Togo, West Africa. "Maybe not knowing as much about where I come from and always feeling a bit foreign in other people's places [made me] want to jump into their lives," he says.

Now that they've found each other, Chris and Stacy are hoping to meet other siblings...if there are any more out there. "I mean, the more the merrier," Stacy says.
Wendy and Ryan

Wendy Kramer and her son, Ryan, are the people to thank for bringing thousands of donor-conceived children together with their half siblings and biological fathers.

In 2000, they created the Donor Sibling Registry website to help Ryan track down his sperm donor father. Since then, thousands of members have logged on to learn more about their genetic origins, and many have found success. Wendy says more than 4,200 people have discovered the identity of their half siblings or donor dad. "There's not a day that goes by that at least two or three people don't match up with each other," she says. "[It's] way beyond our wildest dreams."

Ryan says it's amazing to be able to help children like himself. "I know exactly what it feels like to be searching for your half siblings and your donor, as well," he says. "When I hear these figures...it's a really incredible feeling."

Since launching the website, Ryan says the best experience has been connecting with his half sister, Anna. "She's just delightful, and she's got the best parents," he says. "We couldn't be more happy to have met these people, and it's been just an incredibly enriching and wonderful experience."
Wendy and Ryan

Though websites like the Donor Sibling Registry are helping children find answers, Matthew says it's time for the fertility industry to step up and do the same. "You know, 30,000 children a year being born this way with a lot of unresolved issues in an industry that after 30 [or] 40 years is still kind of a wild, wild West in terms of its regulation," he says.

Matthew says fertility clinics that pay men for sperm donations need to be held to a higher standard. "While I think most of the time that people participating in this are well-intending individuals doing good things and helpful things ... I have to wonder if it's really on the up and up every time," he says. "You've got different fertility clinics on different street corners, and the better your donor portfolio looks, you'll be able to recruit a stronger clientele. How does the family or individual using donated gametes confirm, in fact, that the donor had these credentials?"

Many clinics promise to limit the number of times a donor's sperm can be sold, but Wendy says that doesn't always happen. "On our website, there are groups of families with 40 kids, 60 kids, all from one donor," she says. "There's no tracking. There's no accountability."

Wendy says there's one donor on her website who has fathered 66 children—the highest number she's seen. "It's completely out of control," she says. "Nobody's watching."