BOSTON - Fertility clinics have put a new twist on how to make babies: A "two-mom" approach that lets female same-sex couples share the biological role. One woman's eggs are mixed in a lab dish with donor sperm, then implanted in the other woman, who carries the pregnancy.
A New York doctor described 18 of these cases Tuesday at a fertility conference in Boston that featured other research on ways to help same-sex couples have children. Dr. Alan Copperman is medical director of Reproductive Medicine Associates, a New York City clinic that does the "two-mom" approach.
A New York couple -- Sarah Marshall, 40, a recruiter for law firms, and Maggie Leigh Marshall, 35, a real estate broker -- used it to have their daughter, Graham, now 18 months old. Maggie's eggs were used to make embryos that were implanted in Sarah, and both women are listed as parents on the birth certificate.
"It allowed us both to participate," Sarah Marshall said. "I had to mentally and psychologically give up the idea of, is she going to look like me or my family. But from the time I started carrying her up to now, she is definitely mine."
Maggie Marshall said she had no interest in being pregnant, but "Sarah really wanted to have the experience. We also thought it would be a great way to bond with a kid that ultimately would look a lot like me."
It wasn't cheap -- the couple spent nearly $100,000 on multiple failed attempts before the last one worked. A single in vitro fertilization attempt can run $15,000 to more than $20,000, depending on how much embryo testing is done and whether some embryos are frozen to allow multiple attempts from one batch.
One Canadian study suggests that more lesbian couples have been seeking fertility services in Ontario since same-sex marriage was legalized in the province a decade ago. Some doctors think interest also is up in the U.S. For male couples, many clinics offer egg donors and surrogate moms, using one or both men's sperm.
"The modern family is created in a way that would be humbled by traditional fertility treatments," said Copperman. "We're seeing more and more couples come in and want to share the parenting experience," and their medical forms more often say "wife" rather than "domestic partner."
"This is something that a lot of lesbian couples choose to do" if they can afford it, said Melissa Brisman, a reproductive law specialist in Montvale, New Jersey, who has advised many such couples. "Some doctors really have a problem doing this for non-medical reasons" because any medical procedures carry risks of infections or other complications, she added.
Many fertility specialists are willing, though, and see the risks as small.
"We get same-sex couples from all over the world" because some nations don't allow surrogacy or egg donation, said Roger Good, chief executive officer of HRC Fertility, which runs nine clinics in Southern California.
In the U.S., "there is greater awareness and acceptability" of same-sex relationships, and "less prejudice has allowed them to look at what their options are" for having children, he said.
About 65 gay women and 275 gay men or gay couples have been treated at his clinics in the last year, and doctors there report that "there seems to be an increase over the past couple of years," he said.
In the Canadian study, doctors from the CReATe Fertility Center and the University of Toronto checked patient records for the last 17 years and found that the percentage of women in same-sex relationships using the center's donor sperm rose from 15 percent before gay marriage was legalized in 2003 to 20 percent after the change. Units of donor sperm used by same-sex couples rose from 133 before 2003 to 561 after.
The Boston conference is a meeting of the American Society for Reproductive Medicine and the International Federation of Fertility Societies, a group of 50 fertility societies from around the world.
Follow Marilynn Marchione on Twitter at