IMR Press / CEOG / Volume 44 / Issue 4 / DOI: 10.12891/ceog3496.2017

Clinical and Experimental Obstetrics & Gynecology (CEOG) is published by IMR Press from Volume 46 Issue 1 (2019). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on as a courtesy and upon agreement with S.O.G.

Open Access Original Research
Preliminary study for pregnancy rate according to developmental stages of vitrified-warmed blastocyst
Show Less
1 Department of Obstetrics and Gynecology, Medical Research Institute, Pusan National University, School of Medicine, Busan, Korea
2 Infertility clinic, Pusan National University Hospital, Busan, Korea
Clin. Exp. Obstet. Gynecol. 2017, 44(4), 577–580;
Published: 10 August 2017
Purpose: To examine the pregnancy rate according to developmental stages of vitrified-warmed human blastocyst at the time of embryo transfer (ET). Materials and Methods: Retrospectively, the outcomes of total 140 elective frozen thawed blastocyst transfers were analyzed regarding the embryo developmental stage of the thawed blastocysts at the time of transfer. Group 1 included only expanding blastocysts, group 2 included an expanding blastocyst and a hatching blastocyst, and group 3 included only hatching blastocysts. Results: Implantation rate, clinical pregnancy rate, and ongoing pregnancy rate were significantly higher in group 3 than group 1 and 2. Implantation rates were 32.6% (group 1), 56.6% (group 2), and 77.2% (group 3) (p < 0.05). Clinical pregnancy rates were 25.6% (group 1), 45.3% (group 2) and 70.5% (group 3) (p < 0.05). Ongoing pregnancy rates were 20.9% (group 1), 39.6% (group 2), and 47.7% (group 3) (p < 0.05). Conclusions: Pregnancy rate was higher in transfer of hatching blastocysts than in expanding blastocysts.
Assisted hatching
Frozen-thawed embryo transfer
Hatching blastocyst
Pregnancy rate
Back to top