Ovarian endometriomas are a common and specific manifestation of the disease endometriosis. In vitro fertilization (IVF) treatment in the words of the European Society of Human Reproduction and Embryology (ESHRE) Special Interest Group (SIG) on Endometriosis appears to be appropriate in patients with advanced endometriosis, which is frequently associated with adhesions, ovarian endometriomas, and tubal obstruction. Ovarian responsiveness to hyperstimulation plays a crucial role in determining the success rate of IVF. There are currently insufficient data to clarify whether the endometrioma-related damage to ovarian responsiveness precedes or follows surgery. Elucidation of this point is of utmost interest since it would strongly impact on the decision of whether to operate on women with endometriomas and who are selected for IVF. At present, there appears to be evidence supporting both an endometrioma-related injury and a surgery-mediated damage. The physiological mechanisms leading to ovulation are abnormal in ovaries with endometriomas.

The European Society of Human Reproduction and Embryology (ESHRE) Preimplantation Genetic Diagnosis (PGD) Consortium data collection shows that the most widely used biopsy procedure is indeed cleavage-stage biopsy. Cleavage-stage biopsy of human preimplantation embryos always involves two steps: opening of the zona pellucida (ZP) and subsequent removal of cellular material. The opening of the ZP by laser technology has been introduced in clinical embryo biopsy practice more recently. Compaction in the mammalian preimplantation embryo is an essential event that leads to the formation of the trophectoderm, the inner cell mass and the blastocele. Embryos for PGD by means of PCR are ideally obtained by micro-injection of a single sperm cell in order to avoid contamination with naked sperm DNA. Embryo post- biopsy development can be evaluated on a day, where doubling of cells and/or signs of compaction represents good evolution.