D Nogueira1, C Staessen, H Van de Velde, A Van Steirteghem. 1. Centre for Reproductive Medicine, University Hospital, Dutch-speaking Brussels Free University (Vrije Universiteit Brussel), Brussels, Belgium. lrianad@az.vub.ac.be
Abstract
OBJECTIVE: To analyze embryos after in vitro maturation by investigating their nuclear status and cytogenetic constitution. DESIGN: Prospective randomized laboratory study. SETTING: Reproductive medicine unit in an academic hospital. PATIENT(S): Patients with male and tubal factor infertility undergoing fertility treatment. INTERVENTION(S): Denuded immature oocytes (n = 75) were matured in vitro for 24-30 hours, and intracytoplasmic sperm injection was performed 30 hours after oocyte retrieval. Fluorescence in situ hybridization was performed on the produced embryos. MAIN OUTCOME MEASURE(S): Blastomere content of the total embryo. RESULT(S): The in vitro-matured oocytes showed a similar fertilization rate as the in vivo-matured oocytes, but with a higher incidence of noncleavage (21.0%). In addition, 26.7% of these embryos arrested at the first mitotic division. Thirty embryos were processed for fluorescence in situ hybridization; only 6.7% had all mononuclear blastomeres, 30.0% had at least one binuclear blastomere, 43.3% had at least one multinuclear blastomere, and 56.6% contained anuclear cells. The chromosomal constitution was analyzed in 14 embryos, and chromosomal anomalies were found in 11 (78.5%). CONCLUSION(S): Germinal vesicle oocytes retrieved from superovulated patients and cultured in vitro for a short time had the ability to resume meiosis and achieve fertilization. However, arrest of embryo development was common. These embryos showed a high incidence of multinuclear blastomeres and aneuploidy, suggesting abnormal cytokinesis or genetic abnormalities.
OBJECTIVE: To analyze embryos after in vitro maturation by investigating their nuclear status and cytogenetic constitution. DESIGN: Prospective randomized laboratory study. SETTING: Reproductive medicine unit in an academic hospital. PATIENT(S): Patients with male and tubal factor infertility undergoing fertility treatment. INTERVENTION(S): Denuded immature oocytes (n = 75) were matured in vitro for 24-30 hours, and intracytoplasmic sperm injection was performed 30 hours after oocyte retrieval. Fluorescence in situ hybridization was performed on the produced embryos. MAIN OUTCOME MEASURE(S): Blastomere content of the total embryo. RESULT(S): The in vitro-matured oocytes showed a similar fertilization rate as the in vivo-matured oocytes, but with a higher incidence of noncleavage (21.0%). In addition, 26.7% of these embryos arrested at the first mitotic division. Thirty embryos were processed for fluorescence in situ hybridization; only 6.7% had all mononuclear blastomeres, 30.0% had at least one binuclear blastomere, 43.3% had at least one multinuclear blastomere, and 56.6% contained anuclear cells. The chromosomal constitution was analyzed in 14 embryos, and chromosomal anomalies were found in 11 (78.5%). CONCLUSION(S): Germinal vesicle oocytes retrieved from superovulated patients and cultured in vitro for a short time had the ability to resume meiosis and achieve fertilization. However, arrest of embryo development was common. These embryos showed a high incidence of multinuclear blastomeres and aneuploidy, suggesting abnormal cytokinesis or genetic abnormalities.