Randomized comparison of different ovarian stimulation regimens for assisted reproductive technology in baboons (Papio anubis)

Objective: To compare different methods of ovarian stimulation (OS) for assisted reproductive technology in baboons.

Design: Prospective randomized study.

Setting: Institute of primate research.

Animal(s): Baboons (n = 10) were randomized into two groups (of five animals each) during three different cycles to compare six protocols of OS.

Intervention(s): Cycle 1: clomiphene citrate (CC) alone (group CC) versus CC and GnRH agonist (group CC-Ag); cycle 2: recombinant gonadotropins (GON) without GnRH agonist (group GON) versus GON and depot GnRH agonist (group GON-AgDepo-1); cycle 3: GON and depot GnRH agonist (group GON-AgDepo-2) versus GON and daily GnRH agonist in a classic long protocol (group GON-Ag). Oocyte aspiration was performed 34-36 hours after injecting 5,000 IU rhCG, followed by fertilization via intracytoplasmic sperm injection (ICSI).

Main outcome measure(s): Number and quality of oocytes retrieved and their fertilization rate.

Result(s): More metaphase II (MII) oocytes were retrieved using the GON-AgDepo-1 (n = 12; 64% MII), GON-AgDepo-2 (n = 9; 79% MII), GON-Ag (n = 16; 88% MII), and GON (n = 6; 59% MII) protocols compared with the CC (n = 9; 15% MII) and CC-Ag (n = 14; 20% MII) protocols. Fertilization by ICSI varied between 43% and 71%.

Conclusion(s): In baboons, long and depot protocols yield similar numbers of MII oocytes; however, depot protocol may be preferable because only one injection of GnRH agonist is needed.