A prospective, randomized study comparing day 2 and day 3 embryo transfer in human IVF

Abstract

It is believed that delayed transfer of embryos after IVF allows for a better selection of good quality embryos. Hence, the number of embryos and all other prognostic factors being equal, transfer of day 3 embryos should be associated with higher implantation and pregnancy rates than transfer of day 2 embryos. To investigate this hypothesis, a prospective randomized study was carried out to compare implantation and pregnancy rates between day 2 and day 3 transfers. The relationship between the embryo quality score of day 2 and day 3 embryos and their respective implantation rates was also analysed. In a 2 year period all patients undergoing infertility treatment and in whom at least seven normally fertilized oocytes were obtained were included in the study. A minimization procedure was performed taking into account the patient's age and the method of fertilization (IVF or intracytoplasmic sperm injection). By using a uniform policy of embryo transfer, the number of embryos transferred was similar in both groups. The outcome parameters were embryo quality, implantation and pregnancy rates. No difference was observed in implantation and pregnancy rates between transfers on day 2 versus day 3 (23.8 versus 23.8% and 47.9 versus 46.8% respectively). The incidence of embryos of moderate to poor quality was higher in embryos cultured for 3 days compared with those cultured for 2 days. It is concluded that the outcomes of embryo transfer in terms of implantation and pregnancy rates are comparable for day 2 and day 3 embryos, although the overall embryo quality score decreases when embryos are kept in culture till day 3.

Day 3 embryo transfer may have better pregnancy outcomes in younger than 35-year-old patients with poor ovarian response

“…In this study, the difference in high-quality embryos between day 2 and day 3 embryo transfer suggests that developmental arrest may occur in partial D3 embryos, which leads to lower embryo scoring; but their similar pregnancy outcomes suggest that the developmental arrest in D3 embryos fails to affect pregnancy rates. Laverge et al [14] revealed that although the high-quality embryo rate was higher in day 2 embryo transfer than in day 3 embryo transfer, there were no significant differences in pregnancy rate and implantation rate between day 2 embryo transfer and day 3 embryo transfer, which is similar to our results. In our study, clinical pregnancy rate was higher in day 3 embryo transfer than in day 2 embryo transfer, but there were no significant differences in live birth rate and spontaneous abortion rate between day 3 embryo transfer and day 2 embryo transfer in younger than 35-year-old patients.…”

Hyaluronan in follicular fluid and embryo implantation following in vitro fertilization and embryo transfer

“…There was no difference in the number of embryos transferred or pregnancy rates in our subjects between day 2 and day 3 transfers. This agrees with others' reports [12]. The average number of embryos transferred was two for women < 35 years of age and 3 for those > 35.…”

A Comparative Analysis Between Day 2 and Day 3 Embryo Transfer in IVF/ICSI: A Retrospective Cross-Sectional Study

“…The authors mentioned that if culture conditions are optimized, no differences would be seen in pregnancy rate after ET on day 1or day 2. In other studies, embryos transferred on day 2 were comparable to day 3 (5,6,(17)(18)(19)(20). Although in these studies, in patients with good prognosis, fewer embryos were transferred, in our survey, between the two groups, the number of embryos transferred remained unchanged.…”

“…Many studies also compared day 2 with day 3 ETs, but there seems to be no consensus (4,5,21,22). For example, Laverge et al (6) observed similar clinical pregnancy and implantation rates between days 2 and 3, while overall embryo quality scores were lower on day 3. However, in this study, only a short agonist stimulation protocol was used, which could affect results on oocytes and embryo quality (23) that were different from our study using agonist and antagonist protocols for ovarian stimulation.…”