CRYOPRESERVATION DOES NOT AFFECT THE CLINICAL PREGNANCY RATE OF BLASTOCYSTS DERIVED FROM VITRIFIED OOCYTES.
In recent years, multiple studies have assessed the effect of freezing and thawing of embryos on pregnancy and birth rates, but have reached mixed conclusions. This study compared pregnancy rates in freshly transferred embryos to embryos that were vitrified (frozen) twice, once as an egg and once as an embryo. There was no significant difference in clinical pregnancy rate between the fresh and twice vitrified embryos, however, there was a downward trend (38.63% to 32.46%) of clinical pregnancy rate in the twice vitrified group compared to freshly transferred embryos.