Birth from cryopreserved embryos following in-vitro maturation of oocytes and intracytoplasmic sperm injection

This case report describes the birth of a baby following the transfer ofcryopreserved embryos generated from intracytoplasmic sperm injection(ICSI) carried out on the second day after oocyte pick-up ofin-vitro-matured metaphase I and germinal vesicle stage oocytes. The couplehad a history of three failed intrauterine insemination attempts andreduced fertilization rates in two previous in-vitro fertilization (IVF)cycles. In the IVF-ICSI treatment cycle, 6/11 mature oocytes becamefertilized following ICSI on the first day. However, the patient failed toconceive following the transfer of three embryos. Five oocytes wereimmature (two at metaphase I stage and three with a germinal vesicle) andthese were cultured overnight. All had extruded a polar body by thefollowing day and ICSI was therefore performed; four oocytes becamefertilized, and were cryopreserved at the pronulear stage in propanediol.In the next treatment cycle, transfer of frozen embryos was planned. Thepronuclear zygotes were thawed and cultured for 24 h prior to the transferof two embryos in a cycle stimulated with low doses of follicle stimulatinghormone. This resulted in a pregnancy and the delivery of a healthy babyboy. In-vitro maturation of metaphase I and germinal vesicle oocytes whichare routinely collected in IVF-ICSI cycles, followed by second day ICSIfertilization, may provide a valuable source of embryos for infertilecouples.