The impact of endometriosis on IVF efficacy: qualitative and quantitative assessment of ovarian response and embryo development

Research question: The detrimental effects of endometriosis on IVF success are well known, but the underlying mechanisms are still uncertain. The objective of this study was to investigate the possible detrimental effects of the disease on ovarian response and embryo development. Design: IVF cycles performed in the authors' unit between 2014 and 2020 were retrospectively reviewed. Women with a good ovarian reserve who underwent their first IVF cycle were included. A total of 248 women with endometriosis were identified and matched to 248 women without the disease, according to age, type of stimulation, anti-Mullerian hormone concentration and study period. The primary outcome was the number of women without good-quality embryos. Secondary outcomes included the rate of unexpected poor response (retrieval of <= 3 oocytes), the cumulative clinical pregnancy rate and the cumulative live birth rate. Results: The number of women without good-quality embryos did not differ between women with endometriosis (exposed group) and those without it (unexposed group). The adjusted odds ratio was 0.85 (95% CI 0.51-1.44, P = 0.56). The clinical pregnancy rate and the live birth rate were also similar. Conversely, the rate of unexpected poor response was higher among women with endometriosis (23% versus 13%, P = 0.005). Conclusions: Overall, endometriosis does not markedly affect folliculogenesis and embryo development in the context of IVF. Only an increased risk of unexpected poor response emerged.