Reproductive Associates of Delaware, Newark, Delaware.
Fertil Steril. 2013 Oct;100(4):1008-12. doi: 10.1016/j.fertnstert.2013.06.021. Epub 2013 Jul 19.
To compare pregnancy rates (PRs) using blastocysts cryopreserved on day 7 with those cryopreserved on days 5 and 6.
Retrospective observational cohort study.
Infertility center performing IVF.
PATIENT(S): Eight hundred women with infertility undergoing frozen ET.
INTERVENTION(S): Blastocysts cryopreserved on days 5, 6, and 7 after retrieval were thawed and transferred.
MAIN OUTCOME MEASURE(S): Ongoing PRs (pregnancy developing appropriately into the second trimester). Thaw survival, implantation rates, and clinical PRs were also calculated.
RESULT(S): A total of 1,406 embryos were thawed with a survival of 90.7% for day 5, 83.7% for day 6, and 78.7% for day 7. Implantation rates were 43.3%, 28.9%, and 28.9%, respectively. Ongoing PRs were 43.9%, 32.9%, and 26.7%, respectively.
CONCLUSION(S): Blastocysts cryopreserved on day 7 have a lower, but clinically important potential. Embryos that do not achieve blastocyst stage on day 6 should not be universally discarded, but should be observed in culture 1 more day as 27% may result in an ongoing pregnancy.
比较第 7 天冷冻的囊胚与第 5、6 天冷冻的囊胚的妊娠率（PR）。
回顾性观察队列研究。
进行 IVF 的不孕中心。
800 名接受冷冻 ET 的不孕女性。
解冻并移植第 5、6、7 天回收的囊胚。
持续妊娠率（妊娠适当进入第二个三个月）。还计算了解冻存活率、着床率和临床妊娠率。
共解冻了 1406 个胚胎，第 5 天的存活率为 90.7%，第 6 天为 83.7%，第 7 天为 78.7%。着床率分别为 43.3%、28.9%和 28.9%。持续妊娠率分别为 43.9%、32.9%和 26.7%。
第 7 天冷冻的囊胚妊娠率较低，但具有重要的临床意义。第 6 天未达到囊胚阶段的胚胎不应普遍丢弃，而应在培养中再观察 1 天，因为 27%的胚胎可能会导致持续妊娠。
