Endometriosis Does Not Impair Implantation After Oocyte Donation

Advanced endometriosis does not appear to impair implantation or pregnancy outcomes after oocyte donation, a 10-year study shows

Key Points

Highlights:

• Endometriosis is a major cause of infertility, affecting up to 40% of infertile women, yet its specific impact on the endometrial capability to support an embryo remains a subject of intense scientific debate.

Importance:

• Endometriosis is a leading cause of infertility, affecting up to 40% of women who struggle to conceive.
• However, whether infertility in endometriosis is driven primarily by impaired egg quality or by reduced ability of the endometrium to support implantation remains one of the most debated questions in reproductive medicine.
• Clarifying this distinction has direct implications for treatment selection and counseling.

What’s done here?

• Researchers conducted a single-center retrospective study at Amiens University Hospital to evaluate pregnancy outcomes after oocyte donation in women with and without endometriosis.
• The analysis included 175 oocyte recipients treated between 2011 and 2021: 34 women with surgically or radiologically confirmed stage III–IV endometriosis and 141 women with idiopathic premature ovarian insufficiency serving as controls.
• All participants underwent a standardized hormonal endometrial preparation protocol and received a fresh embryo transfer following IVF with intracytoplasmic sperm injection (ICSI) using donated oocytes. By relying on eggs from healthy donors, the study design aimed to isolate the effect of endometrial receptivity from that of oocyte quality.
• The investigators compared key laboratory and clinical parameters, including the use of GnRH agonists, fertilization rates, embryo number and quality, transfer timing, and pregnancy outcomes. Obstetrical complications such as pre-eclampsia, gestational diabetes, intrauterine growth restriction, and preterm delivery were also assessed.

Key results:

• No statistically significant differences were observed between women with endometriosis and controls in pregnancy rates, clinical pregnancy rates, live birth rates, or obstetrical complications following oocyte donation.
• Women with endometriosis more frequently received GnRH agonists for endometrial preparation (91% vs. 70%), a factor that may have contributed to reducing pelvic inflammation and optimizing the uterine environment.
• Overall, the comparable outcomes between groups indicate that even advanced endometriosis does not appear to impair implantation when oocyte quality is controlled, supporting the hypothesis that infertility in these patients is largely driven by compromised oocyte competence rather than uterine dysfunction.

Strengths and Limitations:

• Strengths are: design that effectively isolates endometrial receptivity by using donated oocytes from endometriosis-free donors, directly addressing a long-standing mechanistic question; the inclusion of only stage III–IV endometriosis provides clarity for patients with severe disease, who represent the greatest clinical challenge; and the comprehensive assessment of both reproductive outcomes and obstetrical complications strengthens clinical relevance.
• Limitations are the retrospective design limits causal inference and introduces potential selection bias;  the relatively small number of patients with endometriosis reduces power to detect subtle differences; only fresh embryo transfers were analyzed, preventing assessment of cumulative pregnancy outcomes from frozen cycles; and findings may not be generalizable to early-stage endometriosis or to cycles using autologous oocytes.

From the Editor-in-Chief – EndoNews

"This study addresses one of the most persistent questions in reproductive medicine: whether infertility in endometriosis is primarily a problem of the uterus or of the oocyte. By using oocyte donation as a natural experimental model, the authors offer a clean and clinically relevant way to disentangle these two mechanisms.

The finding that pregnancy outcomes remain comparable in women with advanced endometriosis when donor eggs are used challenges the long-held assumption that the endometrium is universally compromised in this disease. Instead, it reinforces the concept that ovarian dysfunction—rather than implantation failure—may be the dominant driver of infertility in many patients with severe endometriosis.

Importantly, these results should not be interpreted as minimizing the complexity of endometriosis or its systemic effects. Endometrial biology in endometriosis is heterogeneous, and subtle functional impairments may still exist that are not captured by implantation rates alone. However, the data provide reassurance that, at least in the context of oocyte donation and controlled hormonal preparation, the uterus can remain a competent environment for pregnancy.

Clinically, this study supports a more individualized fertility strategy. For patients with repeated IVF failure linked to poor oocyte yield or quality, oocyte donation should be discussed earlier and more openly as a viable option, rather than a last resort. Scientifically, the work underscores the value of study designs that isolate specific biological variables, moving the field closer to mechanism-based rather than assumption-driven care.

Together, these findings refine our understanding of endometriosis-associated infertility and highlight the importance of aligning treatment decisions with the dominant biological barrier to conception in each patient."

Lay Summary

Endometriosis is a common gynecological disease that affects up to 40% of women experiencing infertility. It can reduce the chance of pregnancy by damaging the ovaries and lowering the number and quality of eggs, through mechanisms such as chronic inflammation, oxidative stress, and tissue scarring. For women with severe disease, infertility is often one of the most distressing consequences.

To better understand whether endometriosis also affects the uterus’s ability to support a pregnancy, researchers from France examined outcomes in women who received donated eggs from healthy donors. This approach allowed them to separate problems related to egg quality from those related to the uterine environment.

The study, led by Jourdaine and colleagues and published in the Journal of Gynecology Obstetrics and Human Reproduction, showed that women with advanced endometriosis had pregnancy and birth rates similar to women without the disease when donor eggs were used. These findings suggest that even in severe endometriosis, the uterus can remain capable of supporting implantation and pregnancy.

For patients whose own eggs do not lead to successful IVF outcomes, oocyte donation may therefore represent a highly effective option, offering a meaningful chance of achieving pregnancy and a healthy birth.

Research Source: https://pubmed.ncbi.nlm.nih.gov/41317989/