Objective

To compare first-trimester fetal crown-rump length (CRL) measurements in pregnancies obtained after thawed blastocyst transfer versus fresh blastocyst transfer after in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

Design

Prospective longitudinal cohort study of CRL Z scores with adjustment for major confounders.

Setting

University-affiliated obstetrics, fetal medicine, and fertility units.

Patient(s)

Singleton gestations conceived via IVF/ICSI and fresh or thawed blastocyst transfer with ultrasound performed at 6–14 weeks of gestational age.

Intevention

None.

Main outcome measure(s)

CRL Z scores.

Result(s)

A total of 365 IVF/ICSI pregnancies were recruited (fresh: 161; thawed: 204). The mean CRL Z score at 6–14 weeks was significantly greater in thawed versus fresh transfers. Different growth trajectories between thawed and fresh transfers were detected: Mean CRL Z score was 0 at 65 days in fresh versus 80 days in frozen. Comparisons of both fresh and thawed transfers with reference values from the general population confirmed significantly lower CRL Z scores in both IVF/ICSI groups (P<.001). The risks of CRL <5th percentile in fresh versus thawed were, respectively 68% vs. 40% at 6 weeks and 2% vs. 1% at 14 weeks. A significant positive correlation between CRL Z scores and birth weight Z scores was found only for fresh transfers, not for thawed.

Conclusion(s)

At 6–14 weeks, thawed blastocyst transfers after IVF/ICSI conceptions present greater CRLs compared with fresh, and both IVF/ICSI groups show smaller CRLs than the general population. This effect is particularly evident before 9 weeks and it may favor birth weight difference of thawed versus fresh BT pregnancies.

中文翻译：

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解冻后与新鲜囊胚移植后使用体外受精或卵胞浆内单精子注射的胎儿冠臀长度增长更大：前瞻性队列研究的二次分析

客观的

比较解冻囊胚移植与体外受精 (IVF)/卵胞浆内单精子注射 (ICSI) 后新鲜囊胚移植获得的妊娠早期胎儿冠臀长度 (CRL) 测量值。

设计

CRL Z评分的前瞻性纵向队列研究，调整了主要混杂因素。

环境

大学附属的产科、胎儿医学和生育单位。

耐心）

单胎妊娠通过 IVF/ICSI 和新鲜或解冻的囊胚移植和超声在 6-14 周胎龄进行。

干预

没有任何。

主要观察指标）

CRL Z分数。

结果）

共招募了 365 名 IVF/ICSI 妊娠（新鲜：161；解冻：204）。6-14 周的平均 CRL Z评分在解冻与新鲜转移中显着更高。检测到解冻和新鲜转移之间的不同生长轨迹：新鲜 65 天的平均 CRL Z得分为 0，而冷冻 80 天。新鲜移植和解冻移植与来自一般人群的参考值的比较证实了两个 IVF/ICSI 组的CRL Z分数显着降低( P <. 001)。新鲜与解冻的 CRL <第 5 个百分位的风险分别在 6 周时为 68% 与 40%，在 14 周时分别​​为 2% 与 1%。CRL Z评分与出生体重Z呈显着正相关 分数仅针对新鲜转移，而不是解冻。

结论

在 6-14 周时，IVF/ICSI 受孕后解冻的囊胚移植显示出比新鲜的更大的 CRL，并且两个 IVF/ICSI 组都显示出比一般人群更小的 CRL。这种影响在 9 周前尤为明显，可能有利于解冻与新鲜 BT 妊娠的出生体重差异。