Clinical outcomes of elective single morula embryo transfer versus elective single blastocyst embryo transfer in IVF-ET
To compare the clinical outcomes of elective single morula embryo transfer (eSMET) versus elective single blastocyst embryo transfer (eSBET) in selected patients.
This study was a retrospective study which analyzed for 271 cycles in women under 37 years of age who are undergoing their first or second trial of in vitro fertilization-embryo transfer (IVF-ET) from January 2008 to December 2009. The eSMET was performed on day 4 (n = 130) and the eSBET was conducted on day 5 (n = 141).
The clinical pregnancy rate (51.5% vs. 51.8%, p = 0.97), implantation rate (52.3% vs. 52.5%, p = 0.98), and live birth rate (39.2% vs. 44.7%, p = 0.36) were similar in the eSMET and eSBET groups, respectively. The miscarriage rate of the eSMET group (23.9%) was slightly higher than that of the eSBET group (13.7%) (p = 0.12), without reaching statistical significance. There was only one case of monozygotic twin pregnancy in each group.
The clinical outcomes of day 4 eSMET were comparable to those of day 5 eSBET. Therefore, day 4 eSMET is a viable option or an alternative to day 5 eSBET, with no difference in success rates.
KeywordsElective single embryo transfer Morula Blastocyst Monozygotic twins Live birth
Conflict of interest
The authors declare that they have no conflict of interest.
- 3.Yokoyama Y, Shimizu T, Hayakawa K. Incidence of handicaps in multiple births and associated factors. Acta Genet Med Gemellol 1995;81–91.Google Scholar
- 10.Henman M, Catt JW, Wood T, Bowman MC, De Boer KA, Jansen R. Elective transfer of single fresh blastocysts and later transfer of cryostored blastocysts reduces the twin pregnancy rate and can improve the in vitro fertilization live birth in younger women. Fertil Steril. 2005;84:1620–7.PubMedCrossRefGoogle Scholar
- 19.Harper M. Gamete and zygote transport. In: Knobil E, Neill J, editors. The physiology of reproduction. New York: Raven; 1994. p. 123–88.Google Scholar
- 21.Gardner DK, Schoolcraft WB. In vitro culture of human blastocysts. In: Jansen R, Mortimer D, editors. Towards reproductive certainty: infertility and genetics beyond 1999: the Plenary Proceedings of the 11th World Congress on In Vitro Fertilization and Human Reproductive Genetics. Pearl River, NY: Parthenon Press; 1999. pp. 378–388.Google Scholar