NEW YORK (Reuters Health) – In vitro maturation of oocytes may be safer, but less successful, than traditional in vitro fertilization in women with polycystic ovaries, a new study has found.
The technique, in which oocytes are taken from unstimulated ovaries, circumvents the risk of the potentially fatal ovarian hyperstimulation syndrome that can occur in IVF.
With a 16.5% live birth rate, however, IVM’s success on that measure was about two-thirds less than with IVF in the retrospective study, which was published online June 1 in Fertility and Sterility.
“(IVM) may never supersede IVF as the gold standard assisted conception treatment, but is available as an option to those requiring an alternative,” Dr. Anne-Sophie Gremeau of the Institute of Reproductive Sciences in Oxford, UK, and colleagues wrote in the paper.
It might be particularly relevant for patients who are concerned about avoiding ovarian hyperstimulation syndrome, especially those who may have suffered the complication during a past IVF treatment and who do not want to risk it again, the researchers suggest.
Dr. Gremeau and colleagues compared 97 first IVM cycles to 97 IVF cycles in matched women with ovulatory or anovulatory polycystic ovaries.
There was little difference in the fertilization rates (just higher than 60% in each group), but the IVF group had significantly higher rates of implantation (39.4% vs 12.9%), clinical pregnancy (ultrasonic evidence of a fetal heart beat at eight weeks gestation; 50.5% vs 19.6%), and live birth (44.3% vs 16.5%).
The live birth rate per cycle observed in this study is in line with the 41.5% U.S. national average for women less than 35 years old, according to the U.S. Centers for Disease Control and Prevention’s 2010 report on assisted reproductive technology.
Miscarriage and multiple pregnancy rates were also similar in the two groups.
Dr. Nanette Santoro, a reproductive endocrinologist at the University of Colorado School of Medicine in Aurora, who was not involved in the research, commented on it for Reuters Health.
“It is easier from a patient’s perspective, to avoid the stimulation medications, monitoring, and side effects — and IVM ‘wins’ in that area, without a doubt. However, this has to be balanced against the substantially lower live birth rate per attempt,” she wrote in an email. “For most patients, the desire for a high live birth rate trumps the simplicity factor associated with IVM.”
There are a few issues that the study did not address, Dr. Santoro says, and they might be targets for future research. For example, do some women have very poor results with IVM and is that predictable? And how do cumulative pregnancy rates over time compare between the two methods?
“It is also likely that IVM techniques will improve over time, and we may see those live birth rate numbers edge up closer to the IVF numbers,” Dr. Santoro said. “That would make this more of a game changer, in my opinion.”
Fertil Steril 2012.