单囊胚冻融移植周期中不同冷冻保存时间对临床妊娠结局和新生儿结局的影响

Effect of cryopreservation time on pregnancy and neonatal outcomes in frozen-thawed single-blastocyst transfer cycles

目的 比较单囊胚冻融移植周期中不同玻璃化冷冻保存时间对胚胎妊娠结局影响。方法 回顾性分析2018-2020年在本生殖中心解冻的9 462个单囊胚冻融移植周期,按冷冻保存时间分组,保存时间0~<2月组有3 350例;2~<6月组有3 224例,6~<12月组有1 448例;≥12月组有1 440例。比较单囊胚冻融移植周期中不同冷冻保存时间对妊娠结局和新生儿结局的影响。结果 四组胚胎复苏存活率、临床妊娠率、流产率及活产率均无统计学差异,新生儿性别比例、分娩方式、出生时孕周、早产儿比例、极低出生体重儿比例以及巨大儿比例差异均无统计学意义,但≥12月组新生儿出生体重及低出生体重儿比例增加,差异有统计学意义。结论 单囊胚冻融移植周期中,囊胚玻璃化冻存时间对临床妊娠结局及新生儿结局无明显影响,但当胚胎冻存时间≥12月时,新生儿出生体重增加,低出生体重儿比例增加,其余指标无明显差异。

Objective To compare the effects of different cryopreservation time on pregnancy and neonatal outcomes in freeze-thawed single-blastocyst transfer cycles. Methods A retrospective analysis was performed on 9462 cycles of freeze-thawed transplantation of single blastocysts in our reproductive center from 2018 to 2020. The cycles were divided into 4 groups according to their cryopreservation time of vitrified embryos: 0-<2 months(3350 cycles), 2-<6 months(3224 cycles), 6-<12 months as(1448 cycles), and ≥12 months(1440 cycles). To compare the pregnancy and neonatal outcomes across the 4 groups. Results There were no statistically significant differences in embryo survival rate, clinical pregnancy rate, miscarriage rate, or live birth rate among the 4 groups(P>0.05). There were no statistically significant differences in newborn sex ratio, delivery mode, gestational age at birth, or proportions of preterm, very low birth weight, and macrosomia(P>0.05), but the birth weight and proportion of low birth weight in group of ≥12 months were significantly higher than other groups(P<0.05). Conclusion In single blastocyst freezing-thawing transfer cycle, the cryopreservation time has no significant effect on the clinical pregnancy and neonatal outcomes, except that when the cryopreservation time was ≥12 months, the birth weight and proportion of low birth weight increased.