Luteinised unruptured follicle syndrome: pathophysiological background and new target therapy in assisted reproductive treatments.

Luteinised unruptured follicle syndrome (LUFS) is a cause of infertility consisting in the unruptured of the dominant follicle after the LH-surge. In fact, during assisted reproductive treatments (ART) clomiphene citrate and letrozole are frequently administered in order to achieve ovulation. However, considering the pathophysiology of LUFS, new possible therapy can be proposed. On this scenario, we performed a review of the literature searching for LUFS recurrency and its impact in infertility and ART. An inflammation theory has been proposed that can be fuel for further therapeutic possibilities. In particular, considering the increase in granulocytes accumulation, the granulocyte colony-stimulating factor (G-CSF) administration has been proposed as target therapy in IUI cycles hampered by LUFS. Although data are encouraging, randomised controlled trials are needed in order to confirm the efficacy of G-CSF administration for LUFS patients.