Embryology Department, Embryolab Fertility Clinic, Thessaloniki, Greece.
Embryolab Academy, Thessaloniki, Greece.
JBRA Assist Reprod. 2024 Aug 26;28(3):399-404. doi: 10.5935/1518-0557.20240014.
To evaluate the impact of double embryo vitrification on clinical outcomes.
This retrospective cohort study included data from January 2013 to March 2021. The study group included women aged 33.3±5.7 years with double-vitrified embryos (n=381), while the control group included women aged 32.1±6.7 years with embryos vitrified once (n=780), all transferred at the blastocyst stage. The primary endpoint was live birth rate (LBR), and secondary endpoints included percent positive βHCG test, clinical/ongoing pregnancy rates, miscarriage/biochemical pregnancy rates and birthweight.
LBR was significantly lower in double-vitrified embryos (30.2%) than in embryos vitrified once (45.6%, p<.05). Similarly, double-vitrified embryos were associated with significantly lower positive βHCG tests (46% vs. 63.3%, p<.05) and clinical (34.9% vs. 52.2%, p<.05) and ongoing pregnancy (31.3% vs. 47.3%, p<.05) rates compared to embryos vitrified once. However, biochemical pregnancy (double vitrified: 24.1% vs. vitrified once: 17.9%, p>.05) and miscarriage rates (double vitrified: 10.2% vs. vitrified once: 9.4%, p>.05), as well as mean birthweight (double-vitrified embryos: 2950g vs. embryos vitrified once: 2837g, p>.05) did not differ significantly between two groups. On a secondary comparison, amongst double-vitrified embryos, the subgroup that was cultured for more than 24 hours between warming and second vitrification achieved significantly higher positive βHCG tests (49%) and clinical pregnancy (38%) rates, compared to embryos re-vitrified on the same day of warming (31.8% and 20.5%, respectively, p<.05). Nevertheless, LBR did not differ significantly amongst these study-group embryos (embryos that remained in culture for more than 24 hours: 32.2% vs. embryos that were re-vitrified on warming day: 20.5%, p>.05).
Double vitrification of embryos adversely affects clinical outcomes. However, it represents a valuable option concerning embryo wastage, with acceptable success rates.
评估双胚胎玻璃化冷冻对临床结局的影响。
本回顾性队列研究纳入了 2013 年 1 月至 2021 年 3 月的数据。研究组纳入了年龄 33.3±5.7 岁的双胚胎玻璃化冷冻患者（n=381），对照组纳入了年龄 32.1±6.7 岁的单胚胎玻璃化冷冻患者（n=780），两组均在囊胚期移植。主要结局为活产率（LBR），次要结局包括β-HCG 阳性率、临床妊娠率、持续妊娠率、流产/生化妊娠率和出生体重。
双胚胎玻璃化冷冻组的 LBR 显著低于单胚胎玻璃化冷冻组（30.2% vs. 45.6%，p<.05）。同样，双胚胎玻璃化冷冻组的β-HCG 阳性率（46% vs. 63.3%，p<.05）、临床妊娠率（34.9% vs. 52.2%，p<.05）和持续妊娠率（31.3% vs. 47.3%，p<.05）均显著低于单胚胎玻璃化冷冻组。然而，生化妊娠率（双胚胎玻璃化冷冻组：24.1% vs. 单胚胎玻璃化冷冻组：17.9%，p>.05）和流产率（双胚胎玻璃化冷冻组：10.2% vs. 单胚胎玻璃化冷冻组：9.4%，p>.05）以及出生体重（双胚胎玻璃化冷冻组：2950g vs. 单胚胎玻璃化冷冻组：2837g，p>.05）在两组间无显著差异。在二次比较中，在解冻和二次玻璃化之间培养超过 24 小时的双胚胎玻璃化冷冻亚组，β-HCG 阳性率（49%）和临床妊娠率（38%）显著高于同一天再玻璃化冷冻的胚胎（分别为 31.8%和 20.5%，p<.05）。然而，这些研究组胚胎的 LBR 无显著差异（在培养中超过 24 小时的胚胎：32.2% vs. 在解冻当天再玻璃化冷冻的胚胎：20.5%，p>.05）。
胚胎的双玻璃化冷冻对临床结局有不利影响。然而，对于胚胎浪费，它是一种有价值的选择，具有可接受的成功率。
