Day 5 versus day 3 embryo transfer: a controlled randomized trial

Abstract

Blastocyst transfer has been suggested to improve implantation rate without affecting pregnancy rate. The aim of this study was to compare the pregnancy and implantation rates of day 3 and 5 transfers in a prospective randomized manner. Patients with four or more zygotes were randomly allocated on day 1 to either day 3 or 5 transfers. Fertilization was achieved through regular IVF or intracytoplasmic sperm injection. Zygotes were kept in Medicult IVF medium for day 3 transfers and transferred into G1.2 and G2.2 on day 1 and 3 respectively for day 5 transfers. The morphologically best two or three embryos or blastocysts were chosen for transfer in both groups. Overall pregnancy rates per embryo transfer were the same (39%) in day 3 and 5 transfers. Implantation rates were 21 and 24% for day 3 and 5 transfers respectively. The pregnancy and implantation rates for day 5 transfers were significantly affected by the availability of at least one blastocyst to transfer and the number of zygotes. The number of good quality embryos on day 3 also significantly affected pregnancy and implantation rates on day 5 transfers. Multiple gestation rate, number of abortions and ongoing pregnancies were similar in both groups. In conclusion, day 3 and 5 transfer had similar pregnancy, implantation and twinning rates. Currently, day 5 transfers have no advantages over day 3 transfers.

Top quality embryos at day 2: a prerequisite for single blastocyst transfer? An observational cohort study in women under 36

“…Many reports have emphasized the difficulties of correctly selecting the best embryo on day 2 [13] 27], whereas in selected patients it ranged from 4.5% [28] to 11% [29]. Only two studies reported cancellation rates of blastocyst transfer in patients without TQE on day 3 [21% [17] and 37% [30]]. By contrast, in our study, only 12% transfers were cancelled when no TQE were available on day 2.…”

Blastocyst vs cleavage‐stage embryo transfer: systematic review and meta‐analysis of reproductive outcomes

“…The following subgroup analyses were performed for ongoing pregnancy/live birth: (1) number of embryos transferred (1; 2; > 2 allowed); (2) 38 Coskun (2000) 39 Emiliani (2003) 40 Fernández-Shaw (2015) 49 Hreinsson (2004) 41 Kolibianakis (2004) 43 Papanikolaou (2005) 46 Papanikolaou (2006) 45 Rienzi (2002) 47 Van der Auwera (2002) …”

Selection of Embryos for Day-3 Transfer at the Pronuclear-Stage and Pronuclear-Stage Cryopreservation Results in High Delivery Rates in Fresh and Frozen Cycles

“…These were higher than those reported in most blastocyst studies even though only 0.88, 0.80, and 0.61 more embryos were cultured for Groups I, II, and III, respectively, than the number transferred. Pregnancy and implantation rates with blastocyst transfer have ranged from 21 to 77% and 9-62%, respectively (2,5,6,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28). With blastocyst transfer, all embryos are retained in culture to ensure at least two high-quality blastocysts are available for transfer.…”

“…Culture of embryos to day-5 or day-6 allows the top-quality embryos in a cohort to develop to good quality blastocysts. However, medium-to-poor quality embryos appear to require the in vivo environment for optimal development beyond day 3 (25,26,28). We have noted that medium-to-poor quality day-3 embryos rarely develop to blastocysts in vitro but often result in pregnancy after day-3 transfer with assisted hatching.…”

“…During the past decade, increasing emphasis has been placed on limiting IVF-ET multiple pregnancies (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)29,(31)(32)(33)(34). Culture of embryos to the blastocyst stage has been advocated as a method for reducing multiple births while maintaining high fresh cycle pregnancy rates (15,16).…”