IVF patients ignore data, keep hoping for twins

It's long been the Catch-22 of in-vitro fertilization: The chances of a successful pregnancy increase with the number of embryos implanted, but so does the likelihood of multiple pregnancies, which are riskier for both mother and offspring.

Now a new study and a growing body of research suggest that, ultimately, implanting only one embryo is just as likely to lead to pregnancy.

More and more doctors are lauding and promoting the practice of these so-called single-embryo transfers. At Massachusetts General Hospital, Dr. Thomas Toth, director of reproductive endocrinology, said it's been his "personal passion" in recent years. In 2006, he said, fully 25 percent of the 500 IVF cycles Mass. General performed were single-embryo transfers.

But other local doctors say that most of their infertility patients simply aren't interested.

That's because with single-embryo transfers it takes more tries -- and therefore more time -- to get pregnant. And when it comes to infertile patients, time is crucial.

"If you were a cancer patient and I told you you'd know if you were cured in two or 12 months, which would you pick?" said Dr. Michael Alper, medical director of Boston IVF, where about 4.5 percent of IVF cycles in 2005 involved an elective single-embryo transfer. "Studies show the stress of infertility is felt to the same degree as the stress associated with cancer."

Dr. Elizabeth Ginsburg, the medical director for Brigham and Women's IVF center, said that until the science exists to help doctors identify which embryos will result in a pregnancy, single-embryo transfers will force many women to wait too long to get pregnant. And the longer they wait, the older they get and the lower their chances of success will be.

"It's a fine line between helping someone get pregnant and not helping them," she said. About 10 percent of the 1,800 IVF cycles performed at Brigham and Women's last year were single-embryo transfers.

IVF science has greatly improved in recent years, increasing pregnancy success rates. That, combined with increasing medical concerns about multiple births, has convinced some infertility doctors that it is time to work on reducing high twin pregnancy rates. Multiple-birth babies are more often born prematurely and more likely to have low birth weight, putting them at risk for health problems later in life.

But according to Dr. Samuel Pang, medical director of Reproductive Science Center in Lexington, this risk doesn't deter patients from wanting multiple embryo transfers.

"Those who have been on the long journey of infertility are quite desperate and are willing to accept the risk of multiples," he said, adding that he's a "strong proponent" of single-embryo transfers and wishes he could bring up his clinic's rate of 11.4 percent in 2005.

In fact, doctors say, research reveals that most patients actually want twins because they see it as a way to assure themselves of two children.

In Massachusetts, where insurance must cover the costs of IVF -- which otherwise would cost about $12,000 per cycle -- the single-embryo transfer rates are generally much higher than in states where IVF is not routinely covered. In 2005, according to the Society for Assisted Reproductive Technology, just over 2 percent of IVF cycles performed by its member clinics across the nation involved single-embryo transfers.

In Europe, however, the practice of single-embryo transfers has taken hold in many countries.

Several local IVF doctors said they hope a new study from the Netherlands will help persuade more patients in the United States to try implanting just one embryo. The study, published earlier this month in the British medical journal The Lancet, compared a group of women under 38 years of age who underwent a milder ovarian stimulation and the transfer of a single embryo -- a process known as Mild IVF -- with a group of women who underwent standard stimulation and multiple embryo transfers.

After one and two IVF cycles, success rates are greater for standard treatment. But the study revealed that if success was measured over the course of a year, the rates of live births were the same in both groups.

"The traditional approach has been to stimulate the ovaries as hard as possible, generate as many eggs as possible and transfer many embryos. The public and the physicians focus on maximizing outcomes in a given cycle," said the study's lead author, Dr. Bart Fauser of the University Medical Center of Utrecht in the Netherlands.

Part of the reason why there is so much focus on maximizing outcomes each cycle in the United States, doctors say, is because the federal government requires clinics to report pregnancy success rates per cycle.

"Patients look for the per-cycle success rate when choosing a clinic," says Dr. Kelly Pagidas, associate chief of reproductive endocrinology at Tufts-New England Medical Center. "They ignore the column lower down that says 40 percent twin rate."

And in Massachusetts, doctors say insurance companies also pay attention to these figures when including clinics in their coverage. It is for these reasons, some specialists say, that doctors themselves may likely be resisting single-embryo transfers for fear of losing business and standing. That's why Fauser said the main message of his study is a broad one: The entire IVF industry needs to change the way it defines success.

"Pregnancy itself is not good enough," Fauser said. "Couples don't come for pregnancy, they come for a healthy child."