Vitrification of human 8-cell embryos, a modified protocol for better pregnancy rates.
Human day 3 embryos were vitrified in modified ethylene glycol-based protocol. The present study reports a post-thaw survival rate of 95.3%, which was significantly higher than that of the conventional slow-freezing protocol (60.0%, P < 0.05). The implantation and pregnancy rates were also higher (14.9% and 35.0%) than that in the slow-freezing protocol (4.2% and 17.4%). On average, three embryos were transferred per patient. Out of the 40 transfer cycles, five deliveries and nine ongoing pregnancies were achieved. Four ended with delivery of a singleton and one a miscarriage. Ethylene glycol is a good cryoprotectant to preserve human 8-cell embryos because of its low toxicity as shown by the high survival rate, and vitrification is a promising alternate to the conventional slow-freezing method.
Rama Raju
Gottumukkala Achyuta
GA
Embryology division, Krishna IVF Clinic, Zillaparishad Junction, Visakhapatnam, Pincode 530002, Andhra Pradesh, India. krishnaivf@yahoo.com
Haranath
Geddam Babu
GB
Krishna
Kota Murali
KM
Prakash
Gomedhikam Jaya
GJ
Madan
Kalagara
K
D000328:Adult; D001755:Blastocyst / Q000166:cytology; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D010064:Embryo Implantation; D004624:Embryo Transfer; D004622:Embryo, Mammalian / Q000166:cytology*; D019855:Ethylene Glycol / Q000494:pharmacology; D005260:Female; D005615:Freezing; D006801:Humans; D011247:Pregnancy; D011256:Pregnancy Outcome; D018873:Pregnancy Rate; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D003451:Cryoprotective Agents; D019855:Ethylene Glycol