Open AccessThe effect of repeated cryopreservation and thawing using cryotip on the clinical outcomes of embryos
Author(s) -
Mizobe Yamato,
Kuwatsuru Yukari,
Kuroki Yuko,
Fukumoto Yumiko,
Tokudome Mari,
Moewaki Harue,
Watanabe Mia,
Tabira Tatsunori,
Iwakawa Tokiko,
Takeuchi Kazuhiro
Publication year - 2021
Publication title -
reproductive medicine and biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.005
H-Index - 22
eISSN - 1447-0578
pISSN - 1445-5781
DOI - 10.1002/rmb2.12365
Subject(s) - cryopreservation , blastocyst transfer , miscarriage , blastocyst , andrology , pregnancy rate , embryo transfer , pregnancy , live birth , medicine , gynecology , embryo , biology , embryogenesis , genetics , microbiology and biotechnology
Purpose To compare the clinical outcomes of embryo transfers that were cryopreserved and thawed two or three times with those cryopreserved and thawed once by CryoTip. Methods Data for 388 single cryopreserved‐thawed blastocyst transfer cycles, performed from April 2012 to March 2014, were assessed. The blastocysts were classified into three groups: blastocysts (A) cryopreserved once, (B) cryopreserved twice, and (C) cryopreserved three times. Results The pregnancy rate was 43.8% (134/306) in group A and 46.3% (38/82) in group B, while the miscarriage rate was 29.1% (39/134) in group A and 23.7% (9/38) in group B. The rate of improvement/maintenance of blastocyst grade was 84.0% (257/306) in group A and 80.5% (66/82) in group B. The pregnancy and miscarriage rates of the blastocysts that showed improvement/maintenance in the grade were 45.9% (118/257) and 29.7% (35/118) in group A and 48.5% (32/66) and 21.9% (7/32) in group B, respectively. The pregnancy rate was 33.3% (2/6), while the miscarriage rate was 0.0% (0/2) in group C. Conclusions Pregnancy rates achieved with re‐cryopreserved and rethawed blastocyst transfer were comparable to those achieved with single cryopreserved‐thawed blastocyst transfer.