Influence of storage time on vitrified human cleavage-stage embryos froze in open system

Abstract

Background: During in vitro fertilization, rapid growth of vitrification and liquid nitrogen storage of embryos have been well characterized. However, the effect of storage time on vitrified cleavage-stage embryos in an open system is poorly understood.

Aims: To investigate the influence of storage time on the survival and pregnancy outcomes of vitrified human cleavage-stage embryos froze and stored in an open system.

Methods: A retrospective study of 786 vitrified-warmed cycles of 735 patients was performed from January 2013 to October 2013. The cycles were divided into five groups according to storage time: 1–3 months, 4–6 months, 7–12 months, 13–24 and 25–60 months. The clinical outcomes of cycles with different storage time were analyzed.

Results: There were no significant differences of the survival rate, clinical pregnancy outcomes, birth rate, gestational weeks and singleton birthweights at various storage times.

Conclusion: For vitrified embryos froze and stored in an open system, the storage time would not influence the survival rate and pregnancy outcomes by storage time up to 5 years.

Chinese abstract

背景: 体外受精, 胚胎玻璃化和液氮储存已被广泛应用。但是对于储存时间在开放系统中对玻璃化裂解胚胎的影响了解的很少。

目的: 将玻璃化人类裂解期胚胎冻结和储存在开放系统中, 研究储存时间对生存和妊娠结局的影响。

方法: 对2013年1月至2013年10月入组的735例患者进行786个玻璃化加热周期的回顾性研究。根据储存时间将周期分为五组: 1-3个月, 4-6个月, 7-12个月, 13-24个月和25-60个月。分析了不同储存时间和加热周期的临床结局。

结果: 不同储存时间下, 各组的生存率、临床妊娠结局、出生率、妊娠周数和单胎体重没有统计学差异。

结论: 在开放系统中冻结并储存玻璃化胚胎, 即使将储存时间提高到5年, 储存时间也不会影响存活时间存活率和妊娠结局。

Keywords:

• Cleavage-stage embryos
• open system
• pregnancy outcomes
• storage time
• survival rate
• vitrification

Declaration of interest

The authors report no conflicts of interest.