There are a number of ways that a couple or a woman can have children, and artificial insemination has been a leading option for many.

An New York Times report tells the story of one of these women - Cynthia Daily, a social worker in Washington. She and her partner used the services of a sperm donor to become pregnant seven years ago. Their son is part of a world wherein children from sperm donation continue to grow.

By accessing a Web-based registry for children fathered by the same donor, Daily has been able to track her son's half-siblings. She has created a online group to be updated on them, and even joins get-togethers with some of them. They constitute an extended family in these modern times.

Today the group has reached a total of 150 children from that one sperm donor. And more and more groups of half-siblings through artificial insemination continue to crop up in Internet.

Concerns On Unlimited Sperm Donation

Parents, donors and experts in the medical field are now having concerns about the negative effect of having so many children from one donor. There is the "possibility that genes for rare diseases could be spread more widely through the population. Some experts are even calling attention to the increased odds of accidental incest between half sisters and half brothers, who often live close to one another," said the New York Times report.

Sperm banks and fertility clinics tend to make much money from people wanting to have children that the ethical side of the business has been overlooked.

According to the report, other countries such as Great Britain, Sweden and France put a limit on how many children a sperm donor can father, but there is specified limit in the United States. There are only guidelines by the American Society for Reproductive Medicine, recommending conceptions by individual donors be limited to 25 births per populations of 800,000.

Families are now calling for legal limits on the number of children allowed per donor.

"Just as it's happened in many other countries around the world," Ms. Kramer said, "we need to publicly ask the questions "What is in the best interests of the child to be born?" and "Is it fair to bring a child into the world who will have no access to knowing about one half of their genetics, medical history and ancestry?" said Wendy Kramer, founder of the Donor Sibling Registry. The Web site donorsiblingregistry.com offers information on a child's half-siblings.

She adds donor families have been treated unfairly by some sperm banks, and that it is time for new legislation.

The Warnock Report produces some recommendation, including the regulation of the sale of human sperms and embryos. It also calls for limiting the number of children a donor could father to 10.

Without limitations, it is possible that a donor can father hundreds of children. It is even possible that accidental incest could occur among these unknown half-siblings, explains Naomie R. Cahn, law professor at George Washington University and the author of "Test Tube Families: Why the Fertility Markets Need Legal Regulation."