Madeline Bowie scanned the face of a man who walked into the coffee shop. It was his nose that she noticed most.

"It's the same as mine," she thought.

She'd been waiting anxiously for this day: It could be the first time Bowie would look into the face of her biological father. "Would he look like me? Act like me?" she wondered. "Is he a good person?"

Paul Mittelstadt was nervous, too. He'd talked to Bowie on the phone, and her calm voice instantly had put him at ease. But was she his daughter?

It took years of searching — and the evolution of the internet — to bring these two together at a Caribou in St. Paul.

Bowie and Mittelstadt are on opposite ends of sperm donation; Mittelstadt was a donor, Bowie's mother a recipient. For most of their lives, they didn't give much thought to the anonymous transfer of gametes, until something changed. For Mittelstadt, curiosity crept in. For Bowie, a hole opened that she wanted to fill.

Now they, like thousands of others, are struggling to find information about their biological relatives. That's not easy in a lightly regulated industry that was once shrouded in secrecy and shame.

Sperm donation operates on the periphery, and without the strict rules, of medicine. Although sperm banks today keep a paper trail, they didn't in the 1970s. And, because it was introduced primarily for heterosexual couples struggling with infertility, the practice favored anonymity.

But the stigma of infertility is fading as the acceptance of nontraditional families grows. Sperm bank users are spread equally among infertile heterosexuals, single women and lesbian couples, and many of them — along with their children — want to know the identity of their donors.

With the ability to share information online, and the rise of DIY genetic test kits from ancestry websites, offspring are finding their donors, whether they want to be found or not.

Mittelstadt wants to be found.

All my children

He estimates that perhaps as many as 40 offspring have his DNA, after four years of sperm donation as a medical student at the University of Minnesota in the 1970s. Now 64, he long has wondered whatever became of the children conceived from his sperm.

"I had all these questions," he said. "What are these people like? How much of my personality is in their character?"

Bowie, whose mother was inseminated in that same clinic in 1976, is looking for the donor who helped bring her into the world. Now 39, she hadn't thought much of her conception until she had children of her own, and saw her facial features and her personality reflected in them. When her first son, Harrison, was born, she began to wonder: "Who is this other person that is part of me and that's part of him?"

Bowie and Mittelstadt connected in an online registry where donor children can find half-siblings. Mittelstadt signed up years ago, but no one had listed themselves as offspring originating from that clinic at that time. No one, that is, until March, when Bowie joined.

When they met, their conversation wasn't all that unusual for a coffee date. They talked about their families and jobs, their interests and personalities. But they also talked about the unusual circumstances that had brought them together.

Mittelstadt was a handsome 23-year-old with a dream of traveling in 1975, his first year of medical school. He had some friends who had gone off to work in Australia, and he wanted to visit, but he didn't have the funds. Through word of mouth, he found out that the University of Minnesota had a fertility clinic — the now closed Reproductive Medicine Center — and was looking for anonymous sperm donors.

Back then, all donations were "fresh" — that is, a donor came in and made a deposit that was given to a patient the same day. (Today, recipients typically use frozen sperm.) Nine or 10 times a month, Mittelstadt left for class a few minutes early, gave his sample and collected around $12. Pretty soon, he had saved up enough to go on a five-week trip.

When he got back, he kept donating. He had a rare blood type that was in demand among families, and the clinic used him all four years of medical school. He started donating at other banks, too. "It was nice cash," he said.

Married seven years, Kate O'Reilly and her husband had tried and tried, but she hadn't gotten pregnant. In 1975, she read an article about artificial insemination and considered it for herself. "It was kind of a nouveau approach," she said.

The U clinic promised to try to match her husband's characteristics to a donor — blue eyes, athletic build, brown hair. That was the only information about the donor she ever got.

She monitored her temperature for a month to deduce when she was fertile, then came in to the clinic for insemination. It cost her $25, and she got pregnant on the first try. "It was a miracle in my life," she said.

No more anonymity

Much has changed in the industry since then. People can shop online for sperm by filtering for interests or ethnicities, hair color or height, and the samples can be shipped worldwide. Users can browse four generations of a donor's family medical history, get information on their college degrees, even see a donor's baby pictures. And people can select a donor who is willing to be identified to offspring when a child turns 18.

"Over time, we're seeing more and more people interested in that, as recipients and children are speaking out about their experiences," said Michelle Ottey, laboratory director for Fairfax Cryobank, which has an outpost in Roseville. "We're learning that kids want more information and that initial contact, even if it's to ask a question. People find value in that connection."

Besides, internet communication and affordable genetic testing have rendered anonymity nearly extinct.

Researchers from the University College London wrote in April in the journal Human Reproduction, "All parties concerned must be aware that, in 2016, donor anonymity does not exist."

"If they put this out on social media that they're a sperm donor, 100 percent they are going to get found," Ottey said.

Wendy Kramer, founder of the Donor Sibling Registry, where Mittelstadt and Bowie connected, recommends ending all pretense of anonymity. Her son, whom she conceived with donor sperm, found his biological father, but only after a painstaking seven-year search.

"Just like in an adoption, it's an innate human desire to want to know where you come from, so why are we deliberately keeping children from half-brothers and -sisters and biological parents?" Kramer asked. "It doesn't make sense."

She calls sperm banks "sperm sellers," a bottom-line industry that targets young guys who just want to earn money for spring break, and doesn't consider the needs of the donors as they mature, or of the children who result.

"The industry only focuses on infertility and getting pregnant," she said. "No one gives a thought to what happens after pregnancy, and I think parents are really vulnerable. When you are feeling that desperate need to have a baby, you kind of push everything to the side, and for decades the industry laid it out that donors will be anonymous, for their own liability."

But as anonymity becomes harder to maintain, advocates for reform suggest requiring counseling for men who donate sperm — same as women who donate eggs or act as surrogates — to give them a view into a future they might not yet comprehend.

"It's a very complex psychological overlay," said Maple Grove attorney Steven H. Snyder, an expert in assisted reproduction law. "A psychological assessment simply raises these issues for discussion, so when they do it, they are thinking, 'Huh, when I'm 40, I might have 12 kids and I won't know where they are. They may want to know who I am. Or if I don't have [my own] children, I may have a gaping emotional hole and want to know them.' "

While counseling is voluntary at Fairfax Cryobank, where about 20 percent of donors are college students, "we do talk to them about all of this," Ottey said. "We expose them to the ideas. These guys are not just popping in off the street and donating sperm; it's a significant commitment."

That wasn't the case in 1975. No one prepared Mittelstadt for the yearning he would later have to find his offspring. He tried to track down records of his donations in the late 1990s and was told by a doctor that they had been destroyed.

Bowie and her mother also put in requests for their medical records from her birth, hoping to find some identifying information about the donor. Meanwhile, Bowie and Mittelstadt separately took saliva samples and mailed them off to Ancestry.com, the family tree website, for a genetic analysis.

Her mother's eyes

Bowie always had her mother's big eyes and her slim build. But she sometimes wondered about the differences in their chins (hers is pointier), earlobes (hers are shorter) and hair (hers is curlier).

And then, there was her nose, a little rounder at the tip than O'Reilly's. It was more like the nose she saw on Mittelstadt, in a coffee shop on Grand Avenue. Was that enough to prove he was her biological father?

"The times are all right, the blood types are right, the physical descriptors are right," she thought. "He looks the part."

More of a "linear" thinker than her mother, Bowie, an attorney, thought she saw something of her personality, as well, in Mittelstadt, an emergency room physician.

In Bowie, Mittelstadt saw the glimmer of a new possibility in his later years. "When you get to be a certain age," he said, "not having children of my own, it would be nice to be connected to relatives."

He also detected in her something deeper than his own curiosity. "I read between the lines a kind of loneliness, not knowing who you belong to, what you belong to."

An only child, Bowie grew up with a father who loved her and helped shape who she is; she even donated a kidney to him. But despite having loving parents and a husband, she admits to feeling "all alone here in the world," without another biological link. And as she gets older, she's faced with an unknown health history that could show up in her or her three young boys.

"Having children triggers a sense of a bigger universe around you," she said, "and how everything relates to you."

So when she met Mittelstadt, she thought, "I kind of wish he is my dad."

Having both sent their saliva to Ancestry.com, Mittelstadt offered to follow up and see if there was a match.

About a week later, while Bowie was at the eye doctor with her 11-year-old son, Mittelstadt sent her an e-mail.

The technician whom he had spoken with "reviewed both our profiles and told us we are not a genetic match," he wrote. "I was ready to cry."

Tears welled up in Bowie's eyes. She had explained her quest to Harrison, but wasn't sure how much of it he had understood. As her tears began to spill over, she looked at her child's face, so much like her own. He put his arm around her and said, "It's OK, Mommy."

Sharyn Jackson • 612-673-4853

@SharynJackson