Treatment with granulocyte colony-stimulating factor in patients with repetitive implantation failures and/or recurrent spontaneous abortions

• Granulocyte colony-stimulating factor (G-CSF) co-regulates oocyte maturation.
• G-CSF influences embryonic development, implantation, and trophoblastic growth.
• G-CSF seems to be beneficial in repetitive implantation failures (RIF).
• G-CSF is beneficial for certain patients with recurrent spontaneous abortions (RSA).
• At present, there is no increased risk of G-CSF application in RIF and RSA patients.

Granulocyte colony-stimulating factor (G-CSF) belongs to the family of colony-stimulating factors (CSF). As the name suggests, it was initially identified as being able to target and influence granulopoiesis, but was soon shown to be a ubiquitous growth factor, with synthesis and receptors, such as the related granulocyte macrophage colony-stimulating factor (GM-CSF), which is found in a wide variety of tissue types, including the organs and cell populations involved in reproduction. It must now be assumed that both G-CSF and GM-CSF control, or play a role in controlling, key processes in oocyte and sperm maturation, endometrial receptivity, implantation, and embryo and fetal development, possibly extending to birth. The following article offers an overview of the current findings with regard to animal experimental studies, initial clinical applications in reproductive medicine, and potential risks.