title: Developmental potential of in vitro or in vivo matured oocytes.
abstract: This study compared the embryological features of mature and immature oocytes (different stages) collected from stimulated cycles of in vitro fertilization (IVF). Immature oocytes were identified, classified as PI (prophase I - germinal vesicle, GV) or MI (metaphase I), were matured in vitro and fertilized using the intra-cytoplasmic sperm injection (ICSI) technique. Fertilization potential, cleavage, and subsequent transfer/cryopreservation of the embryos derived from these in vitro matured oocytes were compared with those of in vivo matured oocytes (collected at the MII stage). The characteristics of embryos derived from gametes recovered in the MI and MII stages were similar. The fertilization rate of immature oocytes recovered in PI was significantly lower than that of MII oocytes (P = 0.031), and the cleavage rate of the PI group was also lower than that of the MI (P = 0.004) and MII (P < 0.001) groups. In vitro maturation of MI oocytes is a suitable alternative when immature oocytes are recovered, as their characteristics and development are similar to those of in vivo matured oocytes. Optimization of outcomes for PI oocytes will require development of techniques that can distinguish which of these gametes will mature and fertilize.
authors.affiliation: Laboratório de Biologia Molecular Endócrina e Tumoral,Universidade Federal do Rio Grande do Sul (UFRGS),Rua Sarmento Leite,Instituto de Ciências Básicas da Saúde,500 Porto Alegre,Rio Grande do Sul,Brazil.
authors.forename: Diego D
authors.initials: DD
authors.lastname: Alcoba
authors.affiliation: Associação Hospitalar Moinhos de Vento,Núcleo de Reprodução Humana Gerar,Rua Ramiro Barcelos,910-8° andar,Cj. 905,Porto Alegre,Rio Grande do Sul,Brazil.
authors.forename: Anita M
authors.initials: AM
authors.lastname: Pimentel
authors.affiliation: Laboratório de Biologia Molecular Endócrina e Tumoral,Universidade Federal do Rio Grande do Sul,Rua Sarmento Leite,Instituto de Ciências Básicas da Saúde,500,Porto Alegre,Rio Grande do Sul,Brazil.
authors.forename: Ilma S
authors.initials: IS
authors.lastname: Brum
authors.affiliation: Laboratório de Ginecologia e Obstetrícia Molecular-Hospital de Clínicas de Porto Alegre,Rua Ramiro Barcelos,2350,Bairro Santa Cecília,Porto Alegre,Rio Grande do Sul,Brazil.
authors.forename: Helena E
authors.initials: HE
authors.lastname: Corleta
mesh_terms: D000328:Adult; D002970:Cleavage Stage, Ovum; D015925:Cryopreservation / Q000379:methods*; D004624:Embryo Transfer; D004622:Embryo, Mammalian; D005260:Female; D005307:Fertilization in Vitro / Q000379:methods*; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010062:Ovulation Induction / Q000379:methods; D058989:Vitrification
keywords: Embryo development; Immature stage; In vitro maturation; Stimulated cycle