Limited Implantation Success of Direct Cleaved Human Zygotes A Time Lapse Study
In a multicenter retrospective study, embryos with direct cleavage from two to three cells (5 hours) had a statistically significantly lower implantation rate than embryos with a normal cleavage pattern.
Irene Rubio, Ph.D., Reidun Kuhlmann, Inge Agerholm, Ph.D., John Kirk, M.D., Javier Herrero, Ph.D., Maria-José Escriba, Ph.D., José Bellver, M.D., Marcos Meseguer, Ph.D.
Volume 98, Issue 6, Pages 1458-1463, December 2012
To evaluate embryos with direct cleavage (≤ 5 hrs) from two to three cells (DC2-3) and correlate this morphokinetic parameter to implantation and ongoing pregnancy.
Clinical multicenter retrospective study.
Private in vitro fertilization centers.
From three clinics, a total of 979 treatments including 5,225 embryos using autologous or donated oocytes, of which 1,659 embryos were transferred.
Main outcome measurements:
Clinical pregnancy confirmed by ultrasound in week 7.
Of the total embryo cohort, 715 (13.7%) underwent direct cleavage from two to three cells, 1659 embryos were transferred to recipients and 109 of the transferred embryos cleaved directly from two to three cells (6.6%). Only one DC2-3 embryo was known to result in a clinical pregnancy (1%) and 80 (73.4%) DC2-3 embryos did not implant. Of the 1550 embryos transferred not showing DC2-3, 203 embryos were from treatments with 100% implantation (13.1%), and 804 (51.8%) embryos did not implant. The known implantation rate of DC2-3 embryos was significantly lower than for embryos with a normal cleavage pattern (1.2% vs. 20.2%, respectively).
Embryos with DC2-3 had a significantly lower implantation rate than embryos with a normal cleavage pattern, suggesting that rejection of these embryos for transfer could improve the implantation rate.
Read the full text at: http://www.fertstert.org/article/S0015-0282(12)01888-2/fulltext