have been donated from donated sperm, a website the donor sibling registry has been connecting them to their fathers and half siblings for the last 13 years. >> i'm brianna. >> kyle. >> nice to meet you. >> adriana and kyle found each other through that registry. >> no legal or social binding but it's half sister, that's cool. >> reporter: so far more than 10,000 connections with been made. todd whitehurst eventually met his daughter, virginia. >> we have a remarkable amount in common. >> it's surprising, really, it's like we're related or something. >> reporter: one more version of the modern american family. ron claiborne, abc news, new york. here's a number for you. 30 to 60,000 children born in the u.s. every year are born via artificial insemination. >> staggering figure. you look at that one woman there.