P-69: Elective transfer of two embryos on day 3 in oocyte donor cycles reduces triplet rate without compromise of pregnancy rate

Abstract

Minimizing the incidence of high order multiple pregnancy is one of the important challenges in clinical ART. Transfer of 2 blastocysts has been reported to reduce the risk of high order multiples. However, blastocyst culture has been associated with a higher risk of monozygotic twinning, particularly in a setting in which both transferred embryos have implanted and triplets result. For this study, we examined our experience with elective transfer of 2 embryos on day 3 of culture in donor egg IVF cycles. Retrospective study in a private assisted reproductive technology program. All donor oocyte cycles in our program from January 2001 until March 2006 are reported. During this time, we recommended transfer of 2 embryos in couples undergoing egg donation. However, twenty eight couples elected to have three embryos transferred. Nine of these patients had somewhat compromised prognosis due to either marginal embryo quality, older age of the donor or suboptimal response to the stimulation. Comparison of couples who chose to transfer 3 embryos versus recommended two embryos are summarized in the table below. Embryos were assessed by cell number and by grade (Grade 1=0-10% fragmentation, Grade 2=10-25% fragmentation, Grade 3=26-50% fragmentation, Grade 4>50% fragmentation). There were no differences between two groups in terms of number of oocytes retrieved, quality of embryos and number of embryos frozen. Clinical pregnancy rates per egg retrieval are reported. 105 cycles with elective transfer of 2 embryos are included. With elective transfer of 2 embryos, the clinical pregnancy rate per retrieval was 60% for egg donor recipients. There were no triplets with elective day 3 transfer of 2 embryos in recipients of donor oocytes. There were no statistically significant differences in pregnancy rates between two groups. Of three triplet pregnancies in patients with three embryos transferred, one spontaneously reduced to a twin pregnancy and two triplet pregnancies underwent selective reduction to twins. Elective day 3 transfer of 2 embryos in oocyte donor cycles yields pregnancy rates comparable to the transfer of three embryos. Transfer of three embryos does not seem to increase pregnancy rates while resulting in a 10% triplet rate.Tabled 1