Endometriomas (endometriosis cysts) can have a negative impact on the surrounding ovarian tissue. As a result, the egg cell reserve decreases and egg cell quality can be impaired. In the context of IVF therapy, a reduced egg cell retrieval is therefore to be expected. Surgical removal of the endometriomas is a very effective therapy, but this damages the surrounding ovarian tissue and results in the loss of egg cells, in the worst case even the removal of the entire ovary.