A new study from Europe questions whether in vitro fertilization (IVF) outcomes are better than other treatments available for infertility.1
While evidence shows IVF can improve the likelihood of pregnancy, the study investigators at the University of Aberdeen in Scotland claim there haven't been many studies to determine whether the procedure results in more live births than other treatments.
A Popular Treatment Option
In vitro fertilization has been available to couples with infertility since the late 1970s. The procedure is often prescribed for women with blocked or absent fallopian tubes, or men who have low sperm counts. It is performed by first removing eggs from the ovary through surgery, then mixing them with sperm in a lab culture. After about 40 hours, the eggs are examined to see if they've become fertilized and are dividing into cells. These resulting embryos are then placed in the female partner's uterus to begin a pregnancy.2
But concerns about cost and potential complications have warranted the need to scrutinize the effectiveness of the procedure against other available therapies, wrote Dr. Zabeena Pandian, a clinical research fellow in the department of Obstetrics and Gynecology at the University of Aberdeen in Scotland and her associates. "With increasing awareness of the role of expectant management and less invasive procedures such as intrauterine insemination [IUI], concerns about multiple complications and costs associated with IVF, it is extremely important to evaluate the effectiveness of IVF against other treatment options…" the research team wrote.
IUI is a procedure in which sperm are separated from semen, then injected through a special syringe directly into the uterus to initiate fertilization. The procedure is performed to coincide with ovulation, and is often used in cases of unexplained infertility and for women undergoing ovulation induction.3
Research Review
In the April issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research, Pandian and her team reviewed previous clinical trials that focused on IVF outcomes, including both pregnancy success and live birth rates. Only randomized controlled trials—which are higher quality—were included in the study, and several databases were searched.
In all, the investigators located a total of 6 studies involving 1,305 women. Each couple involved had tried to conceive for at least one year, and had no obvious fertility abnormalities.
IVF: Live Birth Rates and Pregnancies Achieved
In the end, Pandian and her fellow researchers found that the rate of babies born from IVF procedures was not significantly different than that of artificial insemination and a procedure known as gamete intrafallopian transfer, or GIFT, in which sperm and eggs are placed directly in the fallopian tube, allowing the tube to be the natural incubator.4
Further, the investigators acknowledged that pregnancy rates in the studies focusing on IVF were significantly higher as compared to infertile couples who tried to become pregnant through "watchful waiting". Pregnancy occurred more often after IVF in the studies than after GIFT, as well, the investigators found. For instance, in one study comparing IVF with no intervention, while about 20 of nearly 70 women receiving in vitro fertilization became pregnant, just 1 of 71 women was pregnant after three months with no treatment. In two studies comparing IVF outcomes with those of GIFT, less than half of 84 women became pregnant in the IVF group. But that compares to only 24 of 85 women using GIFT.
The Science is 'Insufficient'
Still, the research team concluded there were too few studies available to draw firm conclusions. "There is insufficient evidence at present to suggest that IVF is more effective than the other treatment options available for unexplained infertility," Pandian and her colleagues wrote. "Various national laws governing IVF treatment, as well as the fact that most IVF treatments are privately funded, make it difficult to randomize clinical trials of infertility treatment," Pandian said. As a result, doctors find it difficult to assign women randomly to non-treatment groups as a comparison in these studies, and often, women who are assigned to no treatment groups eventually drop out, they stated.
Multiple Birth Risk Examined
When Pandian's group examined only the incidence of multiple births in IVF, as compared to IUI and GIFT procedures, there were no significant differences between IVF and artificial insemination, but they did find more multiple births among IVF recipients when they were compared to those who received GIFT. In one study, for example, the rate of multiple births was 53% after IVF, compared to just 17% after GIFT.
The research team could find no studies comparing live birth or pregnancy rates between IVF and treatment with clomiphene citrate (Clomid), a widely used drug prescribed for ovarian stimulation in IVF.
In conclusion, Pandian's team wrote that the effect of IVF compared to other infertility interventions in terms of live-birth rates "remains unknown."
The studies available to date "are limited by their small sample size so that even large differences might be hidden," they added. "Live-birth rates are seldom reported. Periods of follow-up are inadequate and unequal. Adverse effects such as multiple pregnancies and ovarian hyperstimulation syndrome [OHSS] have also not been reported in most studies."
1. Pandian Z, Bhattacharya S, Vale L, Templeton A. In vitro fertilization for unexplained subfertility. Cochrane Database Syst Rev 2005 Apr 18;(2):CD003357.
2. American Society for Reproductive Medicine (ASRM). Frequently Asked Questions About Infertility. Available at: http://www.asrm.org/Patients/faqs.html#Q4:. Accessed May 18, 2005.
3. Fertility Neighborhood. Intrauterine Insemination. Available at: http://www.fertilityneighborhood.com/content/
treatment_options/procedures_for_women_295.aspx.
4. Boston IVF. GIFT – Gamete Intrafallopian Transfer. Available at: http://www.bostonivf.com/undergoing_treatment/
gamete_intrafallopian_transfer.cfm. Accessed May 18, 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.
