In Vitro Fertilization Problems Expand
Even a single baby conceived through IVF may be at risk, new study finds.
MONDAY, Jan. 21, 2002 (HealthDayNews) -- The same fertility problems that can make getting pregnant difficult may also put that pregnancy at risk.
That's the conclusion of a recent study that found that even a single baby conceived through in vitro fertilization (IVF) may be at increased risk for a number of serious problems, including pre-term delivery, low birth weight and even infant death.
While it had long been assumed that an IVF pregnancy involving one baby was far less risky than the more common multiple births, the new study shows pregnancy risks prevail to some degree with all IVF conceptions, even those that produce only one child.
However, the researchers can't explain why.
"The cause could be related to infertility itself -- something inherently different about infertile women that causes them to have high-risk pregnancies. Or it could be related to the [IVF] procedure," says study author Dr. Rebecca Jackson, medical director of the Women's Health Center at San Francisco General Hospital.
Because IVF involves many steps, Jackson adds, there could be problems anywhere along the way.
Risk factors include "the medicines used to induce ovulation, the process of fertilization and growing of the embryo in vitro, the process of re-implanting the embryo back into the uterus," says Jackson, who presented her findings at the recent annual meeting of the American Society for Reproductive Medicine.
For Dr. Jaime Grifo, president of the Society for Assisted Reproductive Technology, the answer is far more likely to be linked to a woman's inherent reproductive problems than the IVF procedure itself.
"The main reason is because the percentage of women who experience these problems is very small in comparison to the large number of women who have IVF," says Grifo, director of the Division of Reproductive Endocrinology at New York University Medical Center.
"If there was something inherently wrong with any step involved in the IVF treatment, then clearly it would be affecting the majority of women who undergo this procedure, and not this very small subset group," Grifo says.
Jackson's study was a comprehensive analysis of 13 studies that examined more than 10,000 IVF pregnancies and 1.5 million natural conceptions. Her goal was to compare the risks of infant mortality, pre-term delivery, low birth weight, and small size for gestational age between the babies of women who conceived naturally and those who became pregnant using IVF.
After taking maternal age into consideration, as well as the number of previous pregnancies, Jackson says the study revealed an overall higher rate of all the complications in the babies of women who conceived via IVF.
From Grifo's viewpoint, the study has some serious flaws, beginning with the comparison of fertile women and infertile women.
"While from a statistical standpoint this is a very sound study, still, you can't compare women who have no fertility problems with those who have inherent problems within their reproductive system, and then hang the outcome on the treatment," says Grifo.
Also important to note, Grifo adds, is the number of healthy women whose babies experience these problems is very small. Even when you see a significant increase in the number of infertile women whose babies have these same difficulties, you are still talking about a very small group, he explains.
"Again, we have to go back to the idea that if, in fact, the problems were the result of the IVF, then we would be seeing much larger numbers of babies with these problems. And this just is not the case," says Grifo.
The "take-home" message of this study, he adds, "is not that IVF causes problems, but that infertile women who finally do conceive should take extra steps to protect their pregnancy by seeking out the care of a high-risk obstetrician."
Jackson contends her study should "serve as a reminder to obstetricians and others who care for pregnant women that IVF singleton pregnancies have higher risks ... [and that] women undergoing IVF should be apprised of this increased risk so that they may make informed decisions about their infertility and obstetrics care."
What To Do: To learn more about IVF, as well as other treatments for infertility, visit The American Society for Reproductive Medicine or the The International Council on Infertility Information Dissemination. For more information on high-risk pregnancies, visit The National Institutes of Health.