Background

背景

Physicians monitor the rising E2 level in relation to follicular growth during in vitro fertilization (IVF) cycles. A drop in E2 level prompts concern regarding possible attrition of follicles or initiation of ovulation prior to trigger injection.

在体外受精（IVF）周期中，医生会监测与卵泡生长有关的E2 水平上升情况。如果 E2 水平下降，医生就会担心在注射触发剂之前，卵泡可能会萎缩或开始排卵。

Objective

目的

The study aimed to evaluate the association between change in E2 levels over the 24-hour period leading up to trigger injection.

该研究旨在评估临近注射触发剂前 24 小时内 E2 水平变化之间的关联。

Materials & Methods

材料与方法

The study included IVF cycles from September 2016 - December 2022. All cycles included vaginal oocyte retrieval (VOR), intracytoplasmic sperm injection (ICSI) and plan to freeze embryos after biopsy and screen by preimplantation genetic testing for aneuploidy (PGT-A). Cycles were grouped by the change in E2 from the day prior to trigger to the day of trigger injection: Group 1: increase in E2 >10%, Group 2: plateau of E2 (between -10% to +10%), Group 3: decrease in E2 >10%. Patient and cycle characteristics including age, AMH, BMI, BAFC, trigger day, estradiol level on day of trigger, change in E2 over 24-hours, number of oocytes retrieved and rates of oocyte maturation, fertilization, blastulation, and euploidy were collected. Comparative analysis was performed using Kruskal-Wallis. Multivariate logistic regression fitted with generalized estimating equation was performed to compare maturity, fertilization, blastulation, and euploidy rates between groups.

研究纳入2016年9月至2022年12月的试管婴儿周期。所有周期均包括阴道取卵（VOR）、卵胞浆内单精子显微注射（ICSI）和胚胎活检后冷冻计划，并通过胚胎植入前遗传学检测（PGT-A）筛查非整倍体。根据从扳机前一天到触发注射当天E2 的变化对周期进行分组：第 1 组：E2 增高 >10%，第 2 组：E2 平台（-10% 至 +10%），第 3 组：E2 下降>10%。收集了患者和周期特征，包括年龄、AMH、BMI、BAFC、扳机日、扳机日的E2水平、24 小时内 E2 的变化、获卵数、卵母细胞成熟率、受精率、胚泡形成率和整倍体率。比较分析采用 Kruskal-Wallis 方法。使用广义评估方程进行多变量逻辑回归，以比较各组间的成熟度、受精率、胚泡形成率和非整倍体率。

Results

结果

A total of 9,421 cycles met inclusion criteria – Group 1: 8373, Group 2: 973, Group 3: 77 cycles. The mean maturation rate was similar between the groups (1: 76.1%, 2: 75.8%, 3: 76.3%, p=0.838). Logistic regression adjusted for age, AMH, BMI, trigger day, E2 level, change in E2, and number of oocytes and mature oocytes retrieved showed significantly lower odds of fertilization (OR 0.66 CI 0.48-0.90 p = 0.009) and blastulation (OR 0.75 CI 0.58-0.98 p = 0.036) in patients with a drop in E2 >10% as compared to an increase in E2 on the day of trigger. Cycles with a plateau in E2 had similar odds of fertilization (OR 1.08 CI 0.98-1.12 p= 0.14) and blastulation (OR 1.07 CI 0.97-1.17 p = 0.18) compared to those with an increase in E2. Euploidy rates showed no difference between groups on unadjusted analysis (45.8% vs 43.2% vs 43.9%, p = 0.073) and showed similar odds of euploidy on adjusted model.

共有9421个周期符合纳入标准，第一组：8373个周期，第二组：973 个周期，第三组：77 个周期。各组的平均成熟率相似（第一组：76.1%，第二组：75.8%，第三组：76.3%，P=0.838）。年龄、AMH、体重指数、扳机日、E2 水平、E2 变化、获卵数和成熟卵泡数经Logistic 回归调整后显示，与扳机日E2上升组相比，E2下降大于 10% 组受精（OR 0.66 CI 0.48-0.90 p =0.009）和胚泡形成的几率（OR 0.75 CI 0.58-0.98% P=0.036）均显著降低。与E2升高的周期相比，E2平台的周期受精几率（OR1.08 CI 0.98-1.12 P =0.14）和胚泡形成几率（OR 1.07 CI 0.97-1.17 p= 0.18）相似。在未调整分析中，各组间的整倍体率没有差异（45.8% vs 43.2% vs 43.9%，p =0.073），在调整模型中，整倍体率相似。

Conclusions

结论

Despite similar oocyte maturity rates, cycles with a drop >10% in E2 from the day before trigger to the day of trigger had significantly lower fertilization and blastulation rates compared to cycles with a plateau or increase in E2 levels. A drop in E2 may be an indicator of reduced embryonic developmental competence. Physicians can be reassured that a plateau in E2 does not portend poor oocyte quality, as shown by similar fertilization and blastulation rates. Furthermore, the change in E2 is not associated with ploidy status of embryos reaching the blastocyst stage. This information can be used to counsel patients regarding potential IVF outcome, given their response to ovarian stimulation.

尽管卵母细胞成熟率相似，但比较从扳机前一天到扳机日 E2的变化情况，下降大于 10% 的周期受精率和胚泡形成率明显低于平台或上升周期。E2 下降可能是胚胎发育能力下降的指标。可以让医生放心的是，E2 处于平台水平并不预示着卵母细胞质量差，受精率和胚泡着床率相似。此外，E2 的变化与囊胚期的胚胎倍性状态无关。根据患者对卵巢刺激的反应，这些信息可用于向患者提供有关潜在试管婴儿结果的建议。

参考文献：

PRE-TRIGGER ESTRADIOL (E2) DYNAMICS: A NON-GENOMIC EVALUATION OF EMBRYO QUALITY Roger, Sarah et al. Fertility and Sterility, Volume 122, Issue 1, e62

Tags： 扳机前雌二醇动态变化：一种非基因组评价胚胎质量的方法