What is the impact of endometriosis and the AFS stage on cumulative pregnancy rates in IVF programs?

Endometriosis is commonly observed in infertile women and can be staged with regard to severity [e.g. according to the American Fertility Society (AFS) classification]. This condition can cause infertility through impaired oocyte quality, fertilization disorders, tubal lesions, adhesions, deep infiltration, and adenomyosis. Although women with endometriosis often turn to in vitro fertilization (IVF) programs, the literature data on IVF outcomes are sometimes contradictory (i.e. the same as in other etiologies of infertility, or worse). The objective of the present study was to assess and compare pregnancy rates in women with and without endometriosis and according to the endometriosis stage.

We retrospectively studied clinical and ongoing pregnancy rates in IVF and the cumulative pregnancy rates after frozen/thawed embryo transfers, in women without endometriosis (group A) or with endometriosis (group B). We further compared groups in which endometriosis was staged according to the revised AFS classification: stage 1/2 (group C), stage 3/4 (group D, without endometrioma), and endometrioma alone (group E).

We documented 430 cycles in group A and 460 in group B (including 56 in group C, 88 in group D and 316 in group E). After fresh or frozen/thawed embryo transfers, the differences in ongoing pregnancy rates between groups A and B were not significant. However the cumulative rates per couple were significantly lower (p < 0.05) in group D.

We recommend IVF for women with endometriosis because the pregnancy rates are similar to those observed for women with other types of infertility. This approach is in line with the international guidelines issued by assisted reproductive technology societies. These results again raise the question of whether surgical resection of deep infiltrating endometriosis (stage 3/4) should be recommended before admission to an IVF program. Trial registration This study was approved by an institutional review board (CPP Ouest VI, Brest, France): reference: B2020CE.43.