FSH replaced by low-dose hCG in the late follicular phase versus continued FSH for assisted reproductive techniques.

During controlled ovarian hyperstimulation (COH) follicle-stimulating hormone (FSH) is frequently used for several days to achieve follicular development. FSH is a relatively expensive drug, substantially contributing to the total expenses of assisted reproductive techniques (ART). When follicles achieve a diameter greater than 10 mm they start expressing luteinising hormone (LH) receptors. At this point, FSH might be replaced by low-dose human chorionic gonadotropin (hCG), which is less expensive. In addition to cost reduction, replacing FSH by low-dose hCG has a theoretical potential to reduce the incidence of ovarian hyperstimulation syndrome (OHSS).