Calculating the Odds of a Baby Through IVF

By Tiffany Sharples, TIME MAGAZINE

Thursday, Jan. 15, 2009--For any woman undergoing in vitro fertilization (IVF) to overcome infertility, the big question is: What are my chances of having a baby? Pretty good, according to a new study, which finds that women's chances of live birth via IVF may be similar to those of other women their age in the general population — better for younger women, not as good for older ones.

In an analysis of the overall live-birth rate for 6,164 patients at a Massachusetts fertility clinic, researchers from Boston IVF and Beth Israel Deaconness Medical Center found that in women ages 39 and younger who were treated with up to six cycles of IVF, the rate of live births ranged from 65% to 86%; in women ages 40 and older, the live-birth rate was 23% to 42%.

"It's fantastic," says Dr. Beth Malizia, lead author of the study, published in the Jan. 15 issue of the New England Journal of Medicine, and a former clinical fellow in obstetrics, gynecology and reproductive biology at Harvard Medical School. "When we got these results we were quite pleased...[IVF] does restore in the infertile population the same live birth rates that they have in their own age group."(See TIME's Top 10 Medical Breakthroughs of 2008)

Not all of the study's more than 6,000 participants became pregnant and gave birth, or underwent the full six cycles of IVF before leaving the clinic, which accounts for the range of live-birth rates. Researchers had to extrapolate from their existing data the likely outcomes for patients who discontinued treatment: In the "optimistic" analysis, researchers assumed that the women who discontinued treatment would have had the same success rates as those who continued treatment; the "conservative" analysis assumes a zero success rate among all women who discontinued IVF at that particular clinic. Realistically, say the authors, the actual live-birth rates would fall somewhere in the middle of the range.

Another possible limitation of the study, the authors say, is the fact that all patients seeking infertility treatment in the state of Massachusetts are at least partially reimbursed by their health-insurance carriers, by law. IVF can cost up to $10,000 or more per cycle, and the study group at the Massachusetts clinic likely included many patients less deterred by financial issues than women in the general population, possibly distorting the data. Malizia, who now serves as a reproductive endocrinologist at Alabama Fertility Specialists in Birmingham, Ala., suggests, however, that the live-birth rates of her study group skewed lower than they might have, had the study been conducted elsewhere. "In states where there's no insurance coverage, there's lower access to IVF treatment," she says. "Those who pursue it may have a better chance of pregnancy, so our suspicion would be that the cumulative rates would be higher in states without insurance." (Read "Predicting In Vitro Success")

Malizia's study may not break new medical ground, but it presents a new perspective on IVF, in that most studies that analyze the treatment's success rates look solely at the outcomes of individual implantations, not the overall possibility of a live birth. Read the entire article...TIME Magazine