Ovaries can be stimulated to produce oocytes for collection during the first phase of the menstrual cycle, German scientists have discovered in findings that offer the hope of restoring fertility to women following cancer treatment.
As conventional ovarian stimulation can leave cancer patients waiting up to 6 weeks before collecting oocytes and starting cancer therapy, Michael von Wolff, from the University of Heidelberg, and colleagues conducted a pilot study of stimulation in the first phase of the menstrual cycle.
Twenty-eight women underwent ovarian stimulation in the proliferative phase of the menstrual cycle using standard medication (group 1). A comparison group of 12 women started stimulation during the luteal phase, using GnRH antagonists and recombinant follicle stimulating hormone to reduce the luteal phase (group 2)
Average ovarian stimulation time was 10.3 days in group 1 and 11.4 days in group 2. The average number of oocytes collected was 13 and 10, respectively, of which 77 percent and 73 percent, respectively, were mature. Intracytoplasmic sperm injection led to fertilization in 70 percent and 75 percent of oocytes, respectively.
Dr von Wolff said: "This new protocol would enable patients with cancers such as breast cancer and Hodgkin lymphoma to have ovarian stimulation and oocyte collection. Waiting for 2 weeks before they start cancer treatment is acceptable for most patients while this process happens."