Does Overnight Culture of Cleaved Embryos Improve Pregnancy Rate in Vitrified-Warmed Embryo Transfer Programme?|
Agha-Rahimi, Azam; Omidi, Marjan; Akyash, Fatemeh; Faramarzi, Azita & Farshchi, Forough Alsadat
Background: Vitrification is a routine procedure in assisted reproductive technique (ART)
lab. However, there is widespread variability between protocols of different centres. The aim of
this study was to compare the chemical pregnancy, clinical pregnancy and live birth rates between
one-day embryo culture and immediate transfer for frozen-thawed embryo transfer (FET) cycles.
Methods: In this cohort retrospective study, 366 FET cycles were divided into two groups:
Group A, the embryos were warmed one day before transfer, and were cultured overnight;
Group B, the embryos were warmed on the same day of transfer, at least were cultured 1 h before
embryo transfer (ET). Chemical and clinical pregnancy and live birth rates were compared between
Results: The chemical pregnancy was higher in group A than B (37.9% versus 28.9%), but
this difference was not significant (P = 0.07). Clinical pregnancy (30.8% versus 24.1%) and live
birth (19.8% versus 22.05%) were similar in group A and B, (P = 0.15), and (P = 0.8).
Conclusion: In conclusion, overnight culture and confirmation of mitosis resumption was
not essential for FET cycles in vitrification method.
vitrification; overnight culture; pregnancy; live birth