Jessica Miglio / DreamWorks DELIVERY MAN

Those of you busy buying tickets to Thor or The Hunger Games, may have missed a movie premiering this week about a man who fathers 533 children. Yes, you read that correctly. In Delivery Man, Vince Vaughn plays a guy who donates to a sperm bank in his 20s and discovers years later that due to a “mixup” at the clinic, he is progenitor of 533 offspring.

And that’s not the only sperm donation story pervading pop culture this week: a new docu-drama premiering on MTV Monday called Generation Cryo follows a teenage girl whose father was a sperm donor as she tries to track down her biological dad and half-siblings; next week, a book by the founder of the Donor Sibling Registry website — the site the teens use in the MTV show — called Finding Our Families: A First-of-Its-Kind Book for Donor Conceived People and Their Families hits shelves.

All this talk of sperm donations has left us with quite a few questions. So we asked experts what you were too embarrassed to ask yourself.

1. Okay, wait. Could someone really father more than 500 children via a sperm bank?

“It would be very difficult logistically to have that many offspring,” says Alice Ruby, Executive Director of the Sperm Bank of California, the only non-profit sperm bank in the country. “Is it possible? Maybe. Is it highly unlikely, yes.”

Grace Centula, Lab Director at Cryos International Sperm Bank in New York estimates that even men with a very high sperm count who donate every week for a year could accomplish maybe thirty pregnancies in that year. It would take decades to have 500 children.

So far, there haven’t been any reports of people fathering 500 children. But there have been reports of people fathering hundreds. In September 2011, the New York Times reported on a man who had fathered 150 children. According to Wendy Kramer, the head of the Donor Sibling Registry Website (which for 13 years has helped donor children and parents to locate and connect half-siblings and biological parents or children and currently has 40,000 members), that group has grown. “That group is now hovering around 200,” she says. “And they’re not the only group.”

2. Two hundred is still a lot of kids! Is that common?

The problem is that there isn’t a regulatory agency governing who is donating sperm, how often and how many pregnancies result from these donations.

“Because nobody is collecting data, we actually have no idea whether 75 or 150 births are an unusually large number or if that’s the norm,” says Rene Almeling, associate professor at Yale and author of Sex Cells: The Medical Market for Eggs and Sperm. She says the last national survey on sperm donation was taken in 1988 by the now-defunct Federal Government Office of Technology Assessment.

3. So are there any regulations on how many children one donor can father?

The national regulations for sperm donation concentrate more on how healthy the sperm is than on how much is donated. “It’s about quality control rather than quantity control,” says Eleanor Nicole at the American Society for Reproductive Medicine, who provides health guidelines for sperm donation. They recommend no more than 25 births per population of 800,000, but nobody enforces that rule. So different banks determine different limits. The Sperm Bank of California limits the number to 10 families per donor. The norm at other banks across the country are in the range of 25 to 50 families.

But even if a bank sets a limit on the number of children a donor can father, the bank depends on families who purchase the sperm reporting back to the bank about successful pregnancies (though a single vial may have millions of sperm, it may take a woman several tries to get pregnant, depending on her age, the method or fertilization, etc.). Sometimes that doesn’t happen.

Kramer at the Donor Sibling Registry thinks this is a major problem: “There’s no oversight. So you can’t limit the number of births until you actually start keeping track of the number of births, you know? And nobody mandates that the sperm industry do that.” Kramer says that the for-profit industry is incentivized to use as many sperm samples from a single donor as possible for pregnancies because a vial of sperm sells for anywhere from $300 to $600. She points to countries like England that do regulate the number of pregnancies that can come from a single donor (10) as a possible model for future regulation.

4. Is it difficult to become a sperm donor?

Donors must be under the age of 40 and free of STIs and HIV. After filling out an application that can be 24 pages long, donors must provide three generations of health information and be tested for diseases that could affect the baby. Many banks also require genetic testing (though the FDA doesn’t require it) and interviews to get a sense of the donor’s personality. The entire screening process takes about eight weeks. And after 18 months, all the sperm (which has been frozen) is tested again for HIV.

Once they’re approved, and only five to 10 percent of applicants actually make the cut, donors have to make deposits at the bank at least once a week for about a year. They’re paid about $100 for each ejaculate that meets the necessary sperm count. “It costs a lot of money to screen the donors, so banks need to make sure they make that money back by getting enough sperm samples from the men,” says Almeling.

During the donation process, donors must abstain from sex 48 before every donation. Plus, donors only get paid when their sperm count meets a certain standard, so “they have to watch how much sleep they get, how much alcohol they’re drinking, how they’re eating. They really have to take care of their bodies,” says Almeling.

It’s not the one-and-done process we usually see on TV that any schlub could do. “A lot of people think it’s like donating blood, and you can just walk in and walk out,” says Ruby at the Sperm Bank of California. “It’s not.”

(MORE: How Eating Fatty Foods May Harm Sperm Quality )

5. Only 5-10% of men qualify–and they have to donate once a week for a year? That’s a more rigorous process than I expected. Who are the men who tend to donate?

Mostly college students. According to Almeling, sperm banks purposely locate themselves near campuses and advertise there to attract young, virile men who need some extra cash. She says, based on her interviews of donors across the U.S., about 80% of them donate purely to make extra cash.

And depending on your credentials, you can earn a decent sum. Some banks charge pay more to men who have PhDs, and at the Cryos bank in New York, men are paid a little bit extra based on how many vials they can fill per ejaculate.

But, according to Ameling, the other 20% of sperm donors are driven by a different motivation: “They’re older men in their 30s. They maybe have children. And they are donating to help people. Usually, they know somebody personally who suffered for infertility, and this is how they’ve decided to give back.”

6. How many men donate sperm every year?

Because nobody regulates sperm donation it’s impossible to tell. Any speculations are based on guesses, not data, according to all the experts interviewed.

7. Do they donate anonymously?

Some do, some don’t.

For most of the 20th century, the sperm donation process was extremely secretive and totally anonymous, catering to couples who could not conceive themselves and didn’t want to advertise their use of a donor. But in the Bay Area in the early 1980s, a feminist health center began asking men if they would be willing to reveal their identities to their offspring when the child turned 18. Why? Because the center realized that it was serving mostly lesbian couples and single women — people who weren’t as concerned about donor secrecy.

The center became the Sperm Bank of California, and they were the first to offer a non-anonymous option (now widely available). Now, donors can choose to make themselves known. Even if the man chooses to be anonymous at the time, banks can connect donors and children once the child has turned 18 with the donor’s permission.

8. How would the child of a sperm donor locate and contact his or her biological father?

Banks of even anonymous donors offer some information to single women or couples looking for sperm: basic physical information, family history, likes and dislikes. Sometimes they share a baby photo, a recording of their voice, educational information and the like. This information can be passed down to the child of the donor.

Those who can’t find their donor through a bank can try the Donor Sibling Registry.

9. How does society feel about sperm donation right now?

Sperm donors, it seems, get a worse rap than they deserve. (This is true in Delivery Man as well in which Vaughn’s character gets criticized for his actions by the media.) “Because sperm donations require masturbation and because of our cultural understanding of what it means to father a child, sperm donation has an unsavory reputation that I don’t think it deserves,” says Ruby at the Sperm Bank of California. “Our donors are very generous men who are helping people make the families they have always dreamed of.”