Married couples seeking fertility treatment are quite common.  The number of single mothers by choice keeps growing.  There is greater public acceptance for same-sex couples becoming parents.  But single men choosing to have children?

That's right.  Single men are in the spotlight of the most recent procreational trend.

Jack Potenza was one of the first single men to take advantage of Dr. Denker's fertility services.  In his late forties, and recently divorced, Potenza told a WPLG TV news reporter about how he fulfilled his dream of becoming a father.

Dr. Denker handled that concern by joining Potenza's sperm with the eggs of a female donor.  A resulting embryo was placed in a surrogate mother.

A few months later, even before his first child was born, Potenza asked Dr. Denker to use another embryo from the same batch to initiate a second surrogacy with another woman.  Potenza now is the proud father of two boys, Sagan and Andrew, both of whom turned 5 this year. 

There are scores of other single men who, like Potenza, are utilizing the marvels of medical technology to have children.

Many are finding their way to the door of Growing Generations, a large surrogacy agency in California.  Stuart Miller, CEO of Growing Generations, says that about 12 percent of his client base is single.

One such client is David, a 51 year-old attorney who told his story to ABC News last year on condition that his last name not be used.

Growing Generations helped David select an egg donor and chose a "gestational carrier."   A "gestational carrier" is a woman who carries an embryo formed by the sperm and egg of the donors.

Financial costs for gestational surrogacy are significant.  The average single man in the Midwest spends between $60,000 and $80,000 in donor, gestational carrier, legal, and medical fees.  Costs on the East Coast and West Coast where medical expenses are higher, come closer to $100,000.

According to statistics kept by the clinic, about 80 percent of the single male clients at the Palm Beach Fertility Clinic are heterosexual.  But single gay men are looking to fertility clinics to become parents too.

Take Chuck Strobel, 40, for example.  This Minneapolis resident told the Pioneer Press that he had considered adoption, but ultimately decided he wanted a child who shared his genes.

Strobel, who is gay and single, went to the International Assisted Reproduction Center.  Baby boy Jacob was born in September 2005.

These three single dads are not unique in America's diverse parenting scene. 

Gail Taylor, president of Growing Generations, says the number of single men using surrogacy services has increased 20 percent in the past two years.  Most are well educated and financially successful.  About half are gay men.

The International Assisted Reproduction Center says that its client base of single men has increased more than 50 percent in the past two years. 

These single men are joining the ranks of unmarried women over 30 who are becoming parents by choice.  The number of such women has increased 50 percent since 1970.

But despite the growing demand, many fertility clinics refuse to provide services to single people. 

The Center for Disease Control found that 16 percent of such clinics in the United States would not treat single women.  I could not find data to document the extent of discrimination against single men.

A report by the American Society for Reproductive Medicine finds that denying such services to single people is unethical.  Before reaching this conclusion, the society considered the reproductive interests of unmarried people, the interests of the children, and the interest of service providers in deciding who to treat and who not to treat.

Ultimately, the society found no sound ethical basis for licensed professionals to deny reproductive services to would-be parents because of their marital status or sexual orientation.

Legal, moral, and ethical debates will likely continue as more single people choose parenthood and seek medical help to accomplish this result.  But in the meantime, more single men are choosing to become parents through unconventional means.