title: Developmental dynamics of IMSI-derived embryos: a time-lapse prospective study.
abstract: Because sperm vacuoles were marked as zones without chromatin in the sperm nucleus, which may reflect underlying chromosomal or DNA defects, this study considered whether they influence the morphology and dynamics of early developmental events in preimplantation embryos. Oocytes were injected with spermatozoa of four classes, according to the number and size of vacuoles at ×6000 magnification, and derived embryos were observed under time-lapse microscopy. For each embryo, the times of pronuclei appearance and disappearance and the first, second and third divisions were determined and related to its respective class of injected spermatozoa and its developmental stage. Embryos arising from normal class-I spermatozoa (without vacuoles) reached the 4-cell stage significantly earlier than embryos developed from class-IV spermatozoa (with large vacuoles and other abnormalities) (P=0.012). Blastocysts from class-I spermatozoa required the shortest mean time for all developmental events in comparison with blastocysts from spermatozoa of other classes (with vacuoles). Blastocysts also showed significantly earlier first division than arrested embryos in embryos arising from class-I spermatozoa (P=0.033). An insight into the developmental dynamics of embryo development according to morphology and head vacuoles of injected spermatozoa in morphologically selected sperm-derived embryos was observed for the first time.
authors.affiliation: Reproductive Unit, Department of Obstetrics and Gynaecology, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Knez
authors.forename: Tomaz
authors.initials: T
authors.lastname: Tomazevic
authors.forename: Eda
authors.initials: E
authors.lastname: Vrtacnik-Bokal
authors.forename: Irma
authors.initials: I
authors.lastname: Virant-Klun
mesh_terms: D000328:Adult; D001755:Blastocyst / Q000166:cytology*; D004477:Ectogenesis; D004624:Embryo Transfer; D005191:Family Characteristics; D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000473:pathology*; D008297:Male; D011247:Pregnancy; D018873:Pregnancy Rate; D011446:Prospective Studies; D055101:Semen Analysis; D017524:Slovenia / Q000453:epidemiology; D013077:Sperm Head / Q000473:pathology; D020554:Sperm Injections, Intracytoplasmic; D013094:Spermatozoa / Q000473:pathology*; D013997:Time Factors; D059008:Time-Lapse Imaging; D014617:Vacuoles / Q000473:pathology*
keywords: IMSI; developmental dynamics; sperm vacuoles; teratozoospermia; time-lapse