Comparison of different regimens of human gonadotropins for superovulation of rhesus monkeys: Ovulatory response and subsequent luteal function

This study was designed to identify suitable treatment regimens of human gonadotropin for superovulation of rhesus monkeys. At menses, female monkeys were given one of three regimens: Plan A [days 1 to 6, 60 IU human follicle-stimulating hormone (hFSH); days 7 to 9, 60 IU hFSH/60 IU human luteinizing hormone (hLH)], Plan B [days 1 to 3, 75 IU FSH/20 IU LH; days 4 to 6, 60 IU FSH/20 IU LH; days 7 to 9, 45 IU FSH/45 IU LH], or Plan C [days 1 to 9, 60 IU FSH/60 IU LH]. On day 10, human chorionic gonadotropin (hCG; 1000 IU) was administered. Serum estrogen levels peaked on the day of hCG treatment (day 10) in Plans A and C but earlier (day 8) in Plan B. An oviduct lavage recovered 1 to 3 oocytes in Plan B but 3 to 13 oocytes in the other treatment groups. Peak progesterone levels in the luteal phase were greater (P<0.05) in animals receiving Plan A or C than Plan B. Regardless of treatment group, progesterone levels declined abruptly 7 days after ovulation induction; the length of the luteal phase in all groups was significantly less than that of normal menstrual cycles. We conclude that regimens of hFSH and hLH (i.e., Plans A and C), followed by hCG, reliably superovulate rhesus monkeys. However, the premature decline in luteal function around the typical time of implantation may compromise pregnancy initiation and maintenance.