In order to select the best embryos we employ blastocyst (day 5 or day 6) transfer.
In order to select the best embryos we employ blastocyst (day 5 or day 6) transfer. Embryos are cultured in the laboratory incubator until they reach the blastocyst stage (5 days after the egg collection day) and then are transferred into the uterus. In certain selected cases this strategy is related to higher pregnancy rates than cleavage stage embryo transfer (good prognosis patients or patients wishing to have a single embryo transfer). Briefly, blastocyst transfer is not indicated for everybody and in fact it might be even worse than day 3 embryo transfer in some cases.
At Pedieos IVF Center we follow the American Society for Reproductive Medicine (ASRM) guidelines which can be found in ASRM website.
Please read below the salient points outlined in the ASRM Practice Committee report 2013:
1. In ‘‘good prognosis’’ patients, blastocyst transfer results in increased live-birth rates compared to transfer of equal numbers of cleavage-stage embryos. Transfer of multiple blastocysts results in a high multiple pregnancy rate.
2. In ‘‘poor prognosis’’ patients, blastocyst transfer has not been shown to result in increased live-birth rates compared with cleavage-stage transfer; however, in these populations there is a higher risk of embryos not progressing to blastocyst stage resulting in fewer/no embryos available for transfer.
3. Extended culture yields fewer surplus embryos for cryopreservation.
4. Blastocyst culture may be associated with a small increased risk of adverse neonatal outcomes, but no causal relationship has been proven.
Please note that:
1.“Good prognosis” patients are defined as patients ≤35 years with ≥10 follicles ≥12mm on the day of hCG injection, normal follicle-stimulating hormone (FSH) and E2 levels, no more than one previous unsuccessful cycle of in vitro fertilization (IVF)–embryo transfer, and good embryo quality.
2. “Poor prognosis” patients are defined as patients >35 years with previous unsuccessful cycle of IVF/embryo transfer, elevated day 3 FSH levels and average to bad embryo quality.