Clinica Eugin, Travessera de les Corts 322, 08029 Barcelona, Spain.
Fundació Privada EUGIN, Travessera de les Corts 314, 08029 Barcelona, Spain.
Hum Reprod. 2018 May 1;33(5):797-806. doi: 10.1093/humrep/dey067.
Does time to ICSI affect reproductive outcomes?
Biochemical and clinical pregnancy diminish progressively as time between oocyte pick up (OPU) and ICSI increases after fresh embryo transfer.
Appropriate oocyte cytoplasmic and nuclear maturation are of paramount importance to ensure an optimal embryonic developmental competence. While nuclear maturation is usually attained by the time an oocyte reaches OPU, cytoplasmic maturation cannot be readily assessed and might be incomplete. On the other hand, excessive in vitro culture of mature human oocytes can affect their ultrastructural characteristics and, in mice, induces alterations in gene expression and changes of chromatin and histone modification patterns.
STUDY DESIGN, SIZE, DURATION: Retrospective consecutive cohort study including 1468 ICSI cycles carried out in a single center between December 2012 and September 2015. All cycles were with patient's own oocytes and fresh embryo transfer (ET). A radiofrequency-based system was used to record exact culture times, namely, OPU-denudation (DN); DN-ICSI and OPU-ICSI. We analyzed the effect of total and partial time intervals between procedures, from OPU to ICSI, on fertilization rate and biochemical, clinical, ongoing pregnancy and live birth rates.
PARTICIPANTS/MATERIALS, SETTING, METHODS: Differences in laboratory times between positive and negative biochemical, clinical, ongoing pregnancies and birth results were tested by Mann-Whitney U test. The likelihood of positive clinical outcomes was further modeled by locally weighted scatterplot smoothing (LOWESS) regression and logistic regression, adjusting for woman's age and BMI, number of transferred embryos; mean embryo morphological score, sperm origin and status, and number of mature oocytes obtained at OPU. Effect of time on fertilization rate was modeled by Generalized Linear Modeling (GLM) and LOWESS regression.
The mean woman's age was 38.4 years (SD 4.6). Biochemical, clinical, ongoing pregnancy and live birth rates after the fresh ET were: 39.6, 33.1, 25.7 and 20.8%, respectively. Cumulative values for biochemical pregnancy and live birth were 46.4 and 26.3%, respectively. Mean times in hours for OPU-DN, DN-ICSI and OPU-ICSI were: 1.00 (SD 0.20); 3.86 (SD 1.93) and 4.87 (SD 1.96), respectively, and were not different for pregnant and non-pregnant patients. However, multivariate analyses showed that on average (anti-log transformed), each 1-h increase in the OPU-ICSI time reduced the likelihood of biochemical pregnancy by 7.3% (95% CI: 0.7-13.5%) and of clinical pregnancy by 7.7% (95% CI 0.8-14.1%), after the fresh ET. No effect of time was observed for ongoing pregnancy or live birth rates. Increasing OPU-ICSI time increased the fertilization rate (B = 0.052, 95% CI: 0.022, 0.082).
LIMITATIONS, REASONS FOR CAUTION: The lack of relationship between incubation time of oocytes and live birth rates might be due to uncontrolled variables. Given the population analyzed, these results should not be extended to other ART protocols such as in vitro maturation of oocytes or classical IVF fertilization.
This study indicates that in vitro ageing of mature oocytes significantly affects the chances to become pregnant. Effect on live birth rates, although not evident in this study, cannot be excluded. Limiting incubation time of mature oocytes in the embryology laboratory should improve reproductive results for patients using their own oocytes and with a transfer of fresh embryos.
STUDY FUNDING/COMPETING INTEREST(S): None.
NA.
ICSI 时间是否会影响生殖结局？
在新鲜胚胎移植后，从卵母细胞采集（OPU）到 ICSI 的时间增加，生化和临床妊娠逐渐减少。
卵母细胞细胞质和核成熟对于确保胚胎最佳的发育能力至关重要。虽然核成熟通常在卵母细胞到达 OPU 时达到，但细胞质成熟不能轻易评估，可能不成熟。另一方面，成熟人类卵母细胞的过度体外培养会影响其超微结构特征，并且在小鼠中，会诱导基因表达的改变以及染色质和组蛋白修饰模式的改变。
研究设计、大小、持续时间：回顾性连续队列研究，包括 2012 年 12 月至 2015 年 9 月在一个中心进行的 1468 个 ICSI 周期。所有周期均使用患者自身的卵子和新鲜胚胎移植（ET）。使用基于射频的系统记录确切的培养时间，即 OPU-去裸（DN）；DN-ICSI 和 OPU-ICSI。我们分析了从 OPU 到 ICSI 的程序之间的总时间和部分时间间隔对受精率以及生化、临床、持续妊娠和活产率的影响。
参与者/材料、设置、方法：通过曼-惠特尼 U 检验检验生化、临床、持续妊娠和出生结果阳性与阴性的实验室时间差异。通过局部加权散点平滑（LOWESS）回归和逻辑回归进一步模拟临床结局阳性的可能性，并调整女性年龄和 BMI、移植胚胎数量；平均胚胎形态评分、精子来源和状态以及 OPU 时获得的成熟卵母细胞数量。通过广义线性模型（GLM）和 LOWESS 回归来模拟时间对受精率的影响。
女性的平均年龄为 38.4 岁（SD 4.6）。新鲜 ET 后的生化、临床、持续妊娠和活产率分别为：39.6%、33.1%、25.7%和 20.8%。生化妊娠和活产的累积值分别为 46.4%和 26.3%。OPU-DN、DN-ICSI 和 OPU-ICSI 的平均时间以小时为单位分别为：1.00（SD 0.20）；3.86（SD 1.93）和 4.87（SD 1.96），并且对于怀孕和未怀孕的患者没有差异。然而，多变量分析表明，平均而言（反对数转换），新鲜 ET 后，OPU-ICSI 时间每增加 1 小时，生化妊娠的可能性降低 7.3%（95%CI：0.7-13.5%），临床妊娠的可能性降低 7.7%（95%CI 0.8-14.1%）。时间对持续妊娠或活产率没有影响。增加 OPU-ICSI 时间会提高受精率（B=0.052，95%CI：0.022，0.082）。
局限性、谨慎的原因：卵母细胞培养时间与活产率之间缺乏关系可能是由于未控制的变量。鉴于分析的人群，这些结果不应扩展到其他 ART 方案，例如卵母细胞体外成熟或经典 IVF 受精。
这项研究表明，成熟卵母细胞的体外老化会显著影响怀孕的机会。尽管在这项研究中没有明显的效果，但不能排除对活产率的影响。限制胚胎实验室中成熟卵母细胞的孵育时间应该会改善使用自身卵子和新鲜胚胎移植的患者的生殖结果。
研究资金/竞争利益：无。
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