Objective

To determine whether the use of slush nitrogen (SN), a super-cooled form of nitrogen with a temperature from −207 to −210 °C, can improve oocyte survival after vitrification and warming compared with conventional liquid nitrogen (LN).

Design

Randomized controlled trial.

Setting

Academic-affiliated private practice.

Patient(s)

A total of 556 metaphase II oocytes from 32 oocyte donor cycles were included.

Intervention(s)

Donor oocytes were block randomized to undergo vitrification with either SN or LN. Vitrification was followed by warming, fertilization with donor sperm, embryo culture to the blastocyst stage, and preimplantation genetic testing for aneuploidy via trophectoderm biopsy with targeted next-generation sequencing.

Main Outcome Measure(s)

The primary outcome was oocyte survival after vitrification and warming. Secondary outcomes included rates of fertilization, usable blastocyst formation, and whole chromosome aneuploidy.

Result(s)

Half of the metaphase II oocytes (n = 278) were randomized to undergo vitrification with SN, whereas the other half (n = 278) were randomized to undergo vitrification with LN. There were no statistically significant differences noted in oocyte survival rate (85.3% vs. 86.3%), fertilization rate (84.0% vs. 80.0%), rate of usable blastocyst formation (54.3% vs. 55.7%), or rate of whole chromosome aneuploidy (9.4% vs. 11.7%) between the SN and LN arms, respectively.

Conclusion(s)

The implementation of an SN oocyte vitrification protocol resulted in similar embryology outcomes compared with LN. The use of SN did not lead to any demonstrable improvement in oocyte survival after vitrification and warming.

Clinical Trial Registration Number

NCT04342364

中文翻译：

---

使用过冷的雪泥氮进行卵母细胞玻璃化后的胚胎学结果与使用传统液氮的结果相似：一项随机对照试验

客观的

为了确定与传统液氮 (LN) 相比，使用雪泥氮 (SN)（一种温度为 -207 至 -210 °C 的过冷形式的氮）是否可以提高玻璃化和升温后的卵母细胞存活率。

设计

随机对照试验。

环境

与学术相关的私人执业。

耐心）

包括来自 32 个卵母细胞供体周期的总共 556 个中期 II 卵母细胞。

干预措施

供体卵母细胞被随机分组​​以接受 SN 或 LN 的玻璃化冷冻。玻璃化之后是升温、供体精子受精、胚胎培养至囊胚阶段，以及通过具有靶向下一代测序的滋养外胚层活检对非整倍体进行植入前基因检测。

主要观察指标）

主要结果是玻璃化​​和升温后的卵母细胞存活率。次要结局包括受精率、可用囊胚形成和全染色体非整倍体。

结果）

半数 II 期卵母细胞 (n = 278) 随机接受 SN 玻璃化冷冻，而另一半 (n = 278) 随机接受 LN 玻璃化冷冻。卵母细胞存活率（85.3% 对 86.3%）、受精率（84.0% 对 80.0%）、可用囊胚形成率（54.3% 对 55.7%）或全染色体率无统计学显着差异SN 和 LN 臂之间的非整倍性（9.4% 对 11.7%）分别。

结论

与 LN 相比，SN 卵母细胞玻璃化方案的实施导致了相似的胚胎学结果。SN 的使用并未导致玻璃化和升温后卵母细胞存活率的任何明显改善。

临床试验注册号

NCT04342364