0 957, 887 person years Parity Clomiphene citrate Gonadotropins hCG GnRH Uterine 1 10 RR Increased risk of uterine cancer in women who use gonadotropins, clomiphene and human chorionic gonadotropin Hannibal et al order priligy Contact your doctor for a pregnancy test before inserting a new ring and using additional back up birth control for 7 days