Extended in vitro maturation of immature oocytes from stimulated cycles: an analysis of fertilization potential, embryo development, and reproductive outcomes.
OBJECTIVE
To investigate 24 h in vitro maturation (IVM) of cumulus-stripped immature oocytes from stimulated cycles.


METHODS
263 oocytes identified as immature after cumulus stripping for ICSI were subjected to in vitro maturation (IVM). Fertilization rates and reproductive outcomes of matured oocytes were compared against 234 in vivo matured sibling oocytes (IVO-MII-Sib) from the same cycles (n = 41). Day 2 embryo development was compared against 116 embryos from ICSI cycles having no IVM (IVO-Ext controls).


RESULTS
While fertilization rates were similar between IVM and IVO-MII-Sib oocytes (62.1% vs. 64.0%, p = 0.9909), day 2 embryo quality was reduced in the IVM group compared with IVO-Ext controls as evidenced by fewer embryos having 4 cells (28.3% vs. 54.3%, p = 0.0026), low fragmentation (30.0% vs. 65.2%, p < 0.0001) or perfectly symmetric blastomeres (28.6% vs. 46.9%, p = 0.0371). 0 of 17 IVM embryos with known fate implanted.


CONCLUSIONS
Efficacy of 24 h IVM for cumulus-stripped GV and MI oocytes for either clinical use or study of normal meiotic maturation is questionable.
Reichman
David E
DE
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA.
Politch
Joseph
J
Ginsburg
Elizabeth S
ES
Racowsky
Catherine
C
D000328:Adult; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000378:metabolism; D047108:Embryonic Development; D005260:Female; D006801:Humans; D009865:Oocytes / Q000254:growth & development*; D010062:Ovulation Induction; D011247:Pregnancy; D018873:Pregnancy Rate; D020554:Sperm Injections, Intracytoplasmic / Q000379:methods*