Successful in vitro maturation of human oocytes not exposed to human chorionic gonadotropin during ovulation induction, resulting in pregnancy

Objective: To report a case of successful in vitro maturation of human oocytes not exposed to hCG during ovulation induction, resulting in pregnancy after transfer of a frozen-thawed embryo resulting from intracytoplasmic sperm injection (ICSI) of the in vitro-matured human oocytes. Design: Clinical study. Setting: Hospital-based private IVF center. Patient(s): A couple with infertility due to severe oligospermia. Intervention(s): Five immature oocytes were retrieved from a patient who failed to use hCG during ovarian stimulation and were cultured for 48 hours in B2 medium containing FSH and hCG. Five oocytes extruded the first polar body and underwent ICSI with frozen-thawed husband spermatozoa. Main Outcome Measure(s): In vitro maturation, fertilization after ICSI, embryo development, and pregnancy. Result(s): All five oocytes extruded the first polar body and were injected using ICSI. Three oocytes were fertilized, but two showed three pronuclei. The remainder, a two-pronuclei embryo subsequently cleaved and was cryopreserved. An ongoing pregnancy was obtained after the transfer of this frozen-thawed embryo. Conclusion(s): Immature human oocytes at the germinal- vesicle stage that have not been exposed to hCG during ovarian stimulation can be matured in vitro and a normal pregnancy can result from ICSI of the in vitro-matured oocytes.