Women who undergo in vitro fertilization (IVF) to conceive are more likely to face various pregnancy-related risks like preeclampsia—maternal high blood pressure associated with pregnancy—and placental abnormalities. That's the conclusion of research released by a group of international medical experts.1
Embedded Risks Possible
But some doctors not connected to the study stress that these pregnancy-related risks are typical of women who had difficulty achieving pregnancy in the first place. "It should not be surprising that women who had a medical problem that made it difficult for them to get pregnant also had problems once they became pregnant," explained William Gibbons, MD, President of the Society for Assisted Reproductive Technology (SART), in a written statement.
"The other complicating factor may be age," said Gibbons, who is a reproductive endocrinologist at the Jones Institute for Reproductive Medicine in Norfolk, Virginia. "Women who undergo infertility treatments are often older than most women who become pregnant. Age, in and of itself, is a risk factor for a more complicated pregnancy."
According to a press release about the study, it's unclear what the underlying reasons for the adverse pregnancy outcomes may be.
Comparative Outcomes Analyzed
The study researchers pulled patient information from a database used in an unrelated clinical trial of singleton pregnancies, known as the First and Second Trimester Evaluation of Risk (FASTER) Trial. They divided the patient data into three groups: those who conceived without the use of assisted reproductive technologies (ART), those who underwent an ovulation induction protocol with or without the use of intrauterine insemination (IUI), and those who used in vitro fertilization, or IVF. (IUI is a procedure in which, unlike IVF, egg and sperm are fertilized in the fallopian tube, similar to what happens naturally. However, sperm is injected into the uterus and is timed with ovulation.)2
The team then looked for any possible association between the type of ART used, as well as whether ART was used at all, and pregnancy outcome.
In all, information on more than 36,000 pregnancies from this original trial was examined. The overwhelming majority involved spontaneous conception; about three-and-a-half percent conceived using ovulation induction with or without IUI; and 1.5% involved the use of IVF, which included gamete intrafallopian transfer (GIFT) and zygote intrafallopian transfer (ZIFT).
The researchers found no association between the use of ART and chromosome abnormalities or birth defects in the children conceived, nor ART and low birthweight in the babies.
However, they did find a link between the use of ART and a higher risk of having an unfavorable pregnancy outcome, especially for those who underwent IVF. Those using IVF were six times as likely to develop certain placental abnormalities like placenta previa, a condition in which the placenta completely or partially covers the cervical opening. IVF patients also had two-and-a-half times the risk of developing preeclampsia, as well as a condition known as placental abruption, which involves the premature separation of the placenta from the uterine wall. Women undergoing IVF were also nearly two-and-a-half times more likely to have undergone a C-section compared to those who used other types of ART or no ART at all.
Miscarriage risk was higher, as well, for those who underwent ovulation induction, the research team found.
The Positive Side
Despite these discoveries, the investigators stressed that the "chances of having a healthy child through ART are, overall, extremely high."
Why is understanding the reality of these risks important? The investigators stress that this knowledge will help doctors counsel patients considering ART about the possibility of adverse pregnancy outcomes.
"We are pleased to see that the study re-affirmed that the children born thanks to these technologies are no more likely to have problems than other children," Gibbons said. "It is important that patients who conceive with the help of assisted reproductive technologies discuss this with their obstetricians."
1. Shevell T, Malone FD, Vidaver J et al. Assisted reproductive technology and pregnancy outcome. Obstet Gynecol 2005 Nov;106(5):1039-45.
2. Fertility Neighborhood. Intrauterine Insemination. Available at: http://www.fertilityneighborhood.com/content/treatment_options/
procedures_for_women_295.aspx. Accessed November 2, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.