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Multiple Births: The More the Merrier?


High Stakes, High Risk

While using fertility drugs alone is relatively affordable, it's also the approach that offers the least control. Whether due to inadequate monitoring or a couple's decision to ignore warnings when a large number of eggs is detected, the majority of very high-order multiple pregnancies result from using just fertility drugs.

Well-publicized examples include the McCaughey septuplets born in Iowa in November 1997 and the Chukwu octuplets born in Texas a year later, both cases involving women in their twenties who only took fertility drugs. While the McCaughey and Chukwu families expressed their joy at having so many children at once, news stories about these dramatic pregnancies and deliveries prompted considerable criticism because of their inherent dangers.

"The risks of multiple gestation for the mom include diabetes, serious blood pressure problems, and bed rest for many months," explains Dr. Copperman, "For the fetuses, the most common risk is prematurity. Babies are being born three and even four months prematurely when they are part of a higher-order gestation. There are problems with the lungs, the eyes, the brains—every major organ system. The baby really needs at least seven or eight months inside to fully mature."

One of the Chukwu babies died shortly after the octuplets' birth, four months premature, and the rest required months of hospitalization. The McCaugheys have disclosed some of the serious problems their babies, born nine weeks early, are experiencing. Two of the seven suffer from different forms of cerebral palsy which prevent them from walking or even sitting up, and scans reveal they have underdeveloped areas in their brains. A third baby requires feeding through a tube in her stomach.

Jody's triplets, Amanda, Hunter and Alexi, were born six weeks early, with only minor complications. Hunter remained on a respirator for a few days and the girls were placed under sun lamps to treat jaundice. But the risks of severe complications, even in a triplet pregnancy, are fueling a drive within the assisted reproduction community toward greater caution and a shift toward techniques that reduce or eliminate the chance of high-order multiples.

"Multifetal pregnancy is a problem that must be solved," one recent editorialist wrote in Fertility & Sterility, the journal of The American Society for Reproductive Medicine (ASRM). The ASRM has urged revision of IVF guidelines to lower the recommended number of embryos placed in women under 35 to two instead of three. The Society has also touted a new IVF technique called blastocyst transfer, which increases pregnancy rates while requiring fewer embryos to be transferred, as "the most promising clinical trend in in vitro fertilization."

Blastocyst Transfer: Later is Better Typically, IVF embryos are transferred to a woman's uterus after two or three days in a culture where they've grown to a size of about eight-to-12 cells. But recently new growing media have made it possible to culture embryos for five or six days before being transferred. The extra time allows them to grow to the larger and more differentiated blastocyst stage. Since generally only the healthiest embryos in a group will survive the additional days, those eventually transferred are of high quality and more likely to result in a successful pregnancy.

Scientists also suspect that blastocyst transfer may be more effective because it is closer to what happens in the body after normal conception. A naturally-conceived embryo is still developing in the fallopian tube at day two or three after fertilization, so the uterine environment might be hostile to an embryo at that stage in some way that is not yet fully understood. By day five, though, a normal blastocyst would already have arrived in the uterus, so a transferred blastocyst may adapt more readily to that environment too.

So far, studies have demonstrated pregnancy rates of 40 percent to 60 percent using the blastocyst transfer technique, compared with the average IVF success rate of 9 percent to 25 percent. And, because of the increased chances for pregnancy, Dr. Kenigsberg points out, "It allows us to put back fewer embryos at one time and avoid the problem of multiple pregnancies, and specifically high-order pregnancies. It's obviously much more natural and much healthier for women to have one baby at a time."


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