Women with more severe stages of endometriosis often find that they need to use IVF in order to successfully conceive. One would expect that the more severe the endometriosis, the less success one can achieve trying to conceive, even using IVF.
According to results of a retrospective study in The Journal of Minimally Invasive Gynecology, in vitro fertilization (IVF) clinical and ongoing pregnancy rates deteriorated with worsening endometriosis. Surprisingly, the presence of endometriomas in patients with stage 3 and 4 endometriosis did not impact IVF outcomes. The Canadian and Israeli study also concluded that the best time to perform IVF appears to be between 7 and 25 months after endometriosis surgery.
Study participants consisted of 216 infertile patients with endometriosis and 209 infertile patients without endometriosis as determined by laparoscopy. Patients with endometriosis were classified according to criteria from the American Society for Reproductive Medicine: stage 1 disease (58 patients), stage 2 (67 patients), stage 3 (63 patients) and stage 4 (28 patients). “We found a consistent decline in clinical and ongoing pregnancy rates with increasing stage of endometriosis,” the author wrote.
Patients with time intervals after surgery of 7 to 12 months and 13 to 25 months achieved the more favorable outcomes. The 7- to 12-month group had a pregnancy rate of 50%, compared with 52.4% for the 13- to 25-month group. In comparison, the pregnancy rate was only 32.5% in the 25-month group, the same as for the 0- to 3-month group. “Although the exact mechanism for impaired fertility during the first 6 months remains to be investigated, the reduced pregnancy rates after 2 years may be explained by either endometriosis recurrence and/or age factors,” the authors wrote.
As one would expect, the authors found that endometriosis is more common in women presenting for infertility evaluation (25% to 50%) compared to the general fertile population (3% to 10%).
Two limitations of the study are that it is retrospective, thus the lack of live birth rate evaluation, and that the surgical intervention for treating endometriosis was not uniform, although 86% of women underwent cystectomy.
One interesting observation that we made after converting most of our cycles to freeze-all cycles with only frozen embryo transfers was that this strategy resulted in patients with endometriosis achieving success rates closer to those without endometriosis than in fresh cycles. So the timing of IVF 7 to 25 months after laparoscopy with a freeze-all cycle and medicated frozen embryo transfer seem to provide the best success rates.