New technique cuts test-tube multiple birth risk

May 17, 1999
Web posted at: 11:56 a.m. EDT (1556 GMT)

From Medical Correspondent Rhonda Rowland

(CNN) -- Researchers say they may have found a way to achieve a high pregnancy rate without the risk of triplets or more. A new technique, blastocyst transfer, may cut down on the number of multiple births associated with in vitro fertilization.

More than 20,000 babies were born with the help of fertility treatments in 1996, according to the Centers for Disease Control and Prevention. Close to 40 percent of the deliveries were multiple births, compared to 2 percent in the general population.

Multiple births are a major complication of IVF, the test-tube baby technique. Fertility experts do not consider it a success, and for parents, it's an enormous emotional and financial challenge.

Blastocyst transfer appealed to Jennifer and Mark Reiser, who spent four years trying to have a baby.

"I just wanted to have a child, and I wasn't necessarily interested in having four at one time," she said. "I wanted a child, and I was going to do everything I could to get the best odds."

With typical IVF, three days after fertilization, up to four embryos are placed in the uterus to maximize chances for a pregnancy.

With blastocyst transfer, the embryos are grown an additional two days -- to the blastocyst stage. Fewer embryos make it this far, but the ones that do are healthier, so doctors place just two in the uterus.

"This is a very, very important breakthrough, and this is the first step in reducing multiple pregnancies," said Dr. Hilton Kort of Reproductive Biology Associates. "The additional bonus is the success rate has increased dramatically."

In Kort's practice, the pregnancy rate with blastocyst transfer is 65 percent. That compares with a pregnancy rate of 30 to 40 percent with typical IVF.

With the procedure, it is unlikely patients could get pregnant with triplets or more, but twins are a very real possibility. At Reproductive Biology Associates, 40 percent of patients got pregnant with twins.

Reiser had two blastocysts implanted, and one has developed into a fetus.

"When it came out to be the one, people asked, 'Are you disappointed?' and I'm like, 'No, I've wanted one all my life,'" she said.

A number of infertility clinics around the world are beginning to offer blastocyst transfer techniques, but not all doctors think it is a panacea.

"The patients that are having difficulty getting pregnant with IVF, blastocyst is not necessarily the answer," said Dr. Michael Steinkampf of the University of Alabama at Birmingham. "The other important point is that blastocyst transfer techniques only decrease the risk of multiple pregnancies if you put fewer embryos back."

Women like Reiser who are 35 or under may be the best candidates for blastocyst transfer.

"I can't wait for it to get here and know how wanted it was," she says. "I just can't wait."

That wait, for a single baby, she says, is the best outcome of all.