Exposure of human oocytes to endometrioma fluid does not alter fertilization or early embryo development

Extensive endometriosis causes a mechanical disturbance in the pelvis leading to obstructive-type infertility. However, minimal or mild endometriosis is suspected to cause infertility, possibly through a humoral agent. Previous studies reported the presence of a factor in the serum of patients with endometriosis which reduced fertilization and early embryo formation in a rat IVF model.

In the present article, we report a comparison of oocytes exposed to endometrioma fluid and oocytes not exposed (controls) in the context of a human IVF setting. We have been in the practice of aspirating oocytes into prewarmed 60-ml syringes containing culture medium. We have shown previously that this technique reduces the length of oocyte retrieval without compromising success. In 14 women undergoing oocyte retrieval, we inadvertently entered an endometrioma. This resulted in retrieved oocytes that were either exposed or not exposed to endometrioma fluid.

In contrast to previous reports, we found no difference in fertilization or early embryo development between the two groups. The fertilization rate for oocytes exposed to an endometrioma was 60%, versus 56% for controls. The good-quality embryo formation rate for oocytes exposed to an endometrioma was 45%, versus 46% for controls.