Artificial insemination is creating new families, and new kinds of stories. The first recorded case was in 1884, when a wealthy Philadelphia couple who was having trouble conceiving, looked to their doctor for help. Without their consent, the doctor secretly conducted an experiment. He chloroformed the woman, and then persuaded his best-looking medical student to donate his seed, and it was injected into the uterus. The woman got pregnant. Twenty-five years later, the medical secret became public and was met with disbelief and outrage. But within a decade or two, artificial insemination had become a treatment for infertility.

In the early days, the procedure was arranged – discreetly through a woman’s fertility doctor. Couples didn’t ask questions about who the man was. And they were advised to keep quiet. By the end of the 1980’s, artificial insemination was becoming big business. Sperm was frozen and banked and a “donor” could be selected from a catalogue. But still the procedure remained secretive.

Today, it’s estimated there could be over one million children conceived through donor insemination. Now, great waves of these children are young adults – and they’re telling us things we never realized. First and foremost, genes do matter - despite what doctors and parents and donors believed. Many offspring genuinely want to know where they came from and who these mystery men are.

Kathleen LaBounty

Kathleen LaBounty was 8 years old when her mother told her that she’d been conceived by artificial insemination and that the father she was growing up with was not biologically related to her. Her genetic father, an anonymous sperm donor, would never be known.

Kathleen was conceived back in the days of fresh donations. A man simply dropped off his sample a few hours before the insemination was to take place. Often, would-be parents didn’t even choose the donors – although Kathleen’s mother did make a special request for one with blue eyes. Because this was considered a “treatment” for infertility, records about these men were scant, if they were kept at all. But Kathleen wants to find this man, her biological father.

All she has to go on is that he probably attended Baylor College of Medicine in 1981 and he probably has blue eyes. So she has photocopied pictures of every male graduate from the Baylor College of Medicine between 1979 and 1984 and has systematically contacted them.

Ryan and Wendy Kramer

Until recently, every search for a sperm donor or half-sibling was a solitary one like this. But in 2003, Wendy Kramer and her teenage son, Ryan, created the Donor Sibling Registry. This is a website designed to help donor-conceived people find their relatives. Over 9,000 people are now members of the DSR and almost 4,000 matches have been made since it started.

Danielle Pagano (top photo), for instance, found her half-sister, JoEllen, in 2005. Since then, she has found out about several other half-siblings. Several of them even met up in New York. Then, in February, 2007, her donor father made himself known. Danielle flew out to meet him in early summer.

Every family tree has an unexpected branch or two. But sperm donation takes this to a whole new level, creating complex family webs. Half-siblings bonding as true siblings. Mothers getting to know each other because they have the same sperm donor. Offspring tracking down and meeting their biological fathers. These family units are so new, it’s hard to even know what to call them.

- Alison Motluk