OBJECTIVE: To compare the outcome of transfer of thawed blastocysts frozen on either day 5 or day 6 after in vitro fertilisation. DESIGN: Cohort observational study. SETTING: Tertiary assisted conception unit in London, UK. POPULATION: Six hundred and forty-two consecutive nondonor programmed thawed blastocyst transfer (TBT) cycles. METHODS: High-grade blastocysts were frozen on day 5 (n = 314) or day 6 (n = 328) after fertilisation using a slow-freezing protocol. Endometrial preparation was performed using estradiol valerate. Progesterone supplementation was commenced when the endometrial thickness had reached 7 mm or more. Frozen blastocysts were thawed on day 6 of progesterone supplementation and assessed immediately after thawing for survival, and after 3-4 hours for blastocoele re-expansion. Main outcome measures Thawed blastocyst survival and re-expansion rates, and pregnancy and live birth rates, per TBT. RESULTS: Thawed blastocyst survival and re-expansion rates were comparable between the day 5 and day 6 groups (87% versus 87%, P = 0.50 and 73% versus 71%, P = 0.35, respectively). The live birth rate was similar between the two groups (29% versus 28.5%, P = 0.93, respectively). After adjusting for confounding variables, the odds ratio (OR) of a live birth in cycles in which the thawed blastocysts were frozen on day 6 compared with day 5 was 1.23 [95% confidence interval (CI), 0.81-1.86, P = 0.34]. CONCLUSION: The pregnancy potential of high-grade blastocysts frozen on day 5 and day 6 after in vitro fertilisation and replaced in programmed TBT cycles is comparable.
OBJECTIVE: To compare the outcome of transfer of thawed blastocysts frozen on either day 5 or day 6 after in vitro fertilisation. DESIGN: Cohort observational study. SETTING: Tertiary assisted conception unit in London, UK. POPULATION: Six hundred and forty-two consecutive nondonor programmed thawed blastocyst transfer (TBT) cycles. METHODS: High-grade blastocysts were frozen on day 5 (n = 314) or day 6 (n = 328) after fertilisation using a slow-freezing protocol. Endometrial preparation was performed using estradiol valerate. Progesterone supplementation was commenced when the endometrial thickness had reached 7 mm or more. Frozen blastocysts were thawed on day 6 of progesterone supplementation and assessed immediately after thawing for survival, and after 3-4 hours for blastocoele re-expansion. Main outcome measures Thawed blastocyst survival and re-expansion rates, and pregnancy and live birth rates, per TBT. RESULTS: Thawed blastocyst survival and re-expansion rates were comparable between the day 5 and day 6 groups (87% versus 87%, P = 0.50 and 73% versus 71%, P = 0.35, respectively). The live birth rate was similar between the two groups (29% versus 28.5%, P = 0.93, respectively). After adjusting for confounding variables, the odds ratio (OR) of a live birth in cycles in which the thawed blastocysts were frozen on day 6 compared with day 5 was 1.23 [95% confidence interval (CI), 0.81-1.86, P = 0.34]. CONCLUSION: The pregnancy potential of high-grade blastocysts frozen on day 5 and day 6 after in vitro fertilisation and replaced in programmed TBT cycles is comparable.
Authors: Sang Min Kang; Sang Won Lee; San Hyun Yoon; Joo Cheol Kim; Jin Ho Lim; Seong Goo Lee Journal: J Assist Reprod Genet Date: 2013-05-30 Impact factor: 3.412
Authors: G M Yerushalmi; T Shavit; S Avraham; M Youngster; A Kedem; I Gat; U S Dorofeyeva; S Mashiach; E Schiff; A Shulman; D S Seidman; A Wiser; E Maman; A Hourvitz; M Baum Journal: Sci Rep Date: 2021-05-21 Impact factor: 4.379
Authors: Andrea Abdala; Ibrahim Elkhatib; Aşina Bayram; Ana Arnanz; Ahmed El-Damen; Laura Melado; Barbara Lawrenz; Human M Fatemi; Neelke De Munck Journal: J Assist Reprod Genet Date: 2022-01-22 Impact factor: 3.412