Age at issue in aneuploidy screening: questions raised about IVF screening practice.(Gynecology)

MONTREAL -- Aneuploidy screening of embryos created through in vitro fertilization will not improve pregnancy rates in women over age 37 if centers already transfer at least three embryos per cycle in this age group, results of a recent study suggest.

"You will not have a higher pregnancy rate if you are [transferring] three embryos anyway. Do not invest a penny in this approach. It is not useful to do this for these patients," said study investigator Dr. Paul Devroey of Dutch-speaking Brussels Free University. He presented the study findings at the 18th World Congress on Fertility and Sterility, sponsored by the International Federation of Fertility Societies.

Recent studies have suggested that between 40% and 64% of in vitro fertilization (IVF) embryos are abnormal in women over age 37, and that preimplantation aneuploidy screening can both increase implantation rates and decrease spontaneous abortion rates.

The rationale for aneuploidy screening of embryos from older but otherwise low-risk women has been to help select the best embryos for transfer, thus improving pregnancy rates.

But Dr. Devroey's study--the first prospective, randomized, controlled trial of this approach--casts doubt on the practice.

In the study, Dr. Devroey and his associates randomized 80 infertility patients (mean age 40) to preimplantation genetic aneuploidy screening or no screening, followed by embryo transfer on day 5. The mean number of embryos transferred in the screened group was 2, compared with 2.8 in the controls.

Although the implantation rate was higher in the screened group (16.5% vs. 10.4%) and the spontaneous abortion rate was lower (7% vs. 10%), the pregnancy rates per embryo transfer were not significantly different between the two groups (36% vs. 32%).