Instituto Bernabeu research looks into whether or not ovarian stimulation factors can affect oocyte morphology and membrane breakage types during ICSI

Instituto Bernabeu research aimed to determine if any ovarian stimulation factors can be linked to oocyte morphology and to the type of membrane breakage when intracytoplasmic spermatozoa injection (ICSI) is performed. This assisted reproduction technique is routinely used in in vitro fertilisation (IVF) laboratories. It has the huge advantage of providing a helping hand when male patients suffer from severe male factors and it stops sperm counts from being a limitation. However, the main disadvantage is that the results depend to a large degree on the operator performing the technique. Although specialists are currently able to perform the process securely, there are some variations in the results that they obtain. Differences between oocytes in ICSI are observed even when an egg donation programme is used.

The research work was presented at the Association for the Study of Reproduction Biology (ASEBIR) Congress. It involved the participation of the Reproduction Biology and Egg Donation Units at Instituto Bernabeu. In order to understand the impact when the technique is performed, egg donors were studied between January and April 2019. The study took the dose and type of gonadotropin, the stimulation initiation phase and duration into account. Both the number of retrieved oocytes and the number of mature oocytes were analysed. When it was time to perform micro-injection, oocyte quality and number of oocytes with a sudden breakage of the plasma membrane were recorded (sudden breakages are an indication of poor quality).

Based on their results, the researchers found that the larger the dose of gonadotropin, the greater the impact in terms of the number of oocytes with a plasma membrane breakage. They point out that additional studies are required in order to determine which factors affect variable results.