VANCOUVER – The Endometriosis Fertility Index accurately predicts a woman’s chances to conceive naturally with endometriosis, according to findings from a prospective cohort study.
“We’re quite confident that this is a very good system to give women a reasonable idea of their chances of conceiving naturally versus a recommendation to have IVF,” Aaron Budden, Bmed, Mmed, of the Royal Hospital for Women in Sydney, said at the World Congress on Endometriosis.
The Endometriosis Fertility Index (EFI) was first published in 2010 (Fertil Steril. 2010 Oct;94[5]:1609-15). In the recent study, researchers found that live birth rates after 3 years closely matched the rates calculated by the tool. “This is one of the most useful systems I’ve ever seen, because it takes into account historical events, as well as the time of endometriosis surgery,” Dr. Budden said.
The researchers enrolled 141 consecutive women who had undergone fertility-saving laparoscopic excision of stage III or stage IV endometriosis and attempted to conceive naturally. During follow-up, the researchers contacted the patients to determine live births, and calculated the EFI score based on a woman’s age, duration of infertility, previous pregnancy, American Society for Reproductive Medicine endometriosis classification, and their least adnexal function score. “The least function score is based off the functional capacity of the fallopian tube, fimbriae, and ovary, where the score is calculated by which of these is least functional on both right and left side,” Dr. Budden said.
The researchers included women with stage III and stage IV endometriosis because this group is often referred for in vitro fertilization (IVF). “But we found that in women with an advanced stage of endometriosis, those with EFI scores of 9 and 10 still had quite a significant chance of conceiving at 3 years, compared to women who had EFI scores of 0 to 2,” Dr. Budden said.
More than a third of the women (35%) had stage III endometriosis, and 65% had stage IV. The mean follow-up period was 56 months. Overall, 46% achieved live births.
In women with an EFI score of 9-10, the success rate was 67% at 3 years. Nearly half (48%) of women with scores of 7-8 were successful at 3 years, as were 38% with scores of 5-6, and 17% with scores of 3-4. Among women with scores of 0-2, there were no live births at 3 years.
About 58% of the women in the study had undergone previous laparoscopic surgery. The researchers found that live births were associated with complete resection of disease (hazard ratio, 2.33; P = .036) and no previous laparoscopy (HR, 2.36; P less than .001).
“One of the things we have to say is that your best chance at conceiving is if you excise all the endometriosis and you do it the first time, rather than needing a second surgery,” Dr. Budden said.
The tool can also be used to help identify patients most likely to benefit from assisted reproduction. Women with EFI scores of 0-2 had a 0% chance of conceiving naturally when followed out to 5 years, but a 39% chance with IVF. “That’s a group that you would thoroughly recommend going to IVF rather than trying to conceive naturally,” Dr. Budden said in an interview.
The study was funded by a variety of non-industry sources. Dr. Budden reported having no financial disclosures.