OBJECTIVE: To characterize incidence, chorionicity, amnionicity, and pregnancy outcome for monozygotic twin pregnancy (MZT) after IVF. DESIGN: Retrospective review. SETTING: University-based fertility center. PATIENT(S): Autologous and oocyte donation IVF cycles eventuating in 4,976 clinical gestations from 2000 to 2007. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): MZT incidence, chorionicity, zygosity, pregnancy outcome. RESULT(S): Ninety-eight MZTs were diagnosed after first-trimester ultrasound evaluation (2% incidence). The incidence in cycles transfering autologous oocytes was 1.7% but was 3.3% with donor oocytes; however, women <35 years old using their own oocytes displayed a similar rate (3.1%) to women using donor oocytes. Eighty MZTs occurred after fresh day-5 transfer; only 14 followed fresh day-3 transfer (2.6% vs. 1.2%). The MZT incidence in day-3 transfers without hatching was not different from those with hatching (1.3% vs. 1.1%). In addition, MZT incidence did not differ significantly whether or not ICSI was performed (2.4% vs. 2.0%). Four MZTs occurred after frozen-thawed embryo transfer (0.8% incidence). Ninety-five percent of all placental arrangements were confirmed as monochorionic-diamniotic on obstetric ultrasounds. CONCLUSION(S): These findings confirm a higher incidence of MZT after IVF. Monochorionic-diamniotic implantations were increased, whereas monochorionic-monoamniotic were not. The MZT risk factors included young age and extended culture, but not zona penetration or cryopreservation. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
OBJECTIVE: To characterize incidence, chorionicity, amnionicity, and pregnancy outcome for monozygotic twin pregnancy (MZT) after IVF. DESIGN: Retrospective review. SETTING: University-based fertility center. PATIENT(S): Autologous and oocyte donation IVF cycles eventuating in 4,976 clinical gestations from 2000 to 2007. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): MZT incidence, chorionicity, zygosity, pregnancy outcome. RESULT(S): Ninety-eight MZTs were diagnosed after first-trimester ultrasound evaluation (2% incidence). The incidence in cycles transfering autologous oocytes was 1.7% but was 3.3% with donor oocytes; however, women <35 years old using their own oocytes displayed a similar rate (3.1%) to women using donor oocytes. Eighty MZTs occurred after fresh day-5 transfer; only 14 followed fresh day-3 transfer (2.6% vs. 1.2%). The MZT incidence in day-3 transfers without hatching was not different from those with hatching (1.3% vs. 1.1%). In addition, MZT incidence did not differ significantly whether or not ICSI was performed (2.4% vs. 2.0%). Four MZTs occurred after frozen-thawed embryo transfer (0.8% incidence). Ninety-five percent of all placental arrangements were confirmed as monochorionic-diamniotic on obstetric ultrasounds. CONCLUSION(S): These findings confirm a higher incidence of MZT after IVF. Monochorionic-diamniotic implantations were increased, whereas monochorionic-monoamniotic were not. The MZT risk factors included young age and extended culture, but not zona penetration or cryopreservation. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.
Authors: Denis A Vaughan; Robin Ruthazer; Alan S Penzias; Errol R Norwitz; Denny Sakkas Journal: J Assist Reprod Genet Date: 2015-11-18 Impact factor: 3.412