Backgroud This study’s objectives were to compare the clinical, perinatal, and obstetrical outcomes of patients with different estradiol (E2) levels in fresh single-blastocyst-transfer (SBT) cycles under an early follicular phase prolonged regimen on the day of trigger. Methods We recruited patients in fresh SBT cycles (n = 771) undergoing early follicular phase prolonged protocols with β-hCG values above 10 IU/L between June 2016 and December 2018. Patients who met the inclusion and exclusion criteria were divided into four groups according to their serum E2 level percentages on the day of trigger: <25th, 25th–50th, 51st–75th, and >75th percentile groups. Results Although the rates of clinical pregnancy (85.57% (166/194)), embryo implantation 86.60% (168/194), ongoing pregnancy (71.13% (138/194)), and live birth (71.13% (138/194)) were lowest in the >75th percentile group, we did not observe any significant differences (all P > 0.05). We used this information to predict the rate of severe ovarian hyperstimulation syndrome (OHSS) area under the curve (AUC) = 72.39%, P = 0.029, cut off value of E2 = 2,893 pg/ml with the 75% sensitivity and 70% specificity. The 51st–75th percentile group had the highest rates of low birth weight infants (11.73% (19/162), P = 0.0408), premature delivery (11.43% (20/175), P = 0.0269), admission to the neonatal intensive care unit (NICU) (10.49% (17/162), P = 0.0029), twin pregnancies (8.57% (15/175), P = 0.0047), and monochorionic diamniotic pregnancies (8.57% (15/175); P = 0.001). We did not observe statistical differences in obstetrics complications, including gestational diabetes mellitus (GDM), gestational hypertension, placenta previa, premature rupture of membranes (PROM), and preterm premature rupture of membranes (PPROM). Conclusion We concluded that serum E2 levels on the day of trigger were not good predictors of live birth rate or perinatal and obstetrical outcomes. However, we found that high E2 levels may not be conducive to persistent pregnancies. The E2 level on the day of trigger can still be used to predict the incidence of early onset severe OHSS in the fresh SBT cycle.

中文翻译：

---

根据触发雌二醇水平的日期，在早期卵泡期延长方案下新鲜单囊胚移植周期的临床和围产期结果

背景 本研究的目的是比较不同雌二醇 (E2) 水平的患者在触发当天的早期卵泡期延长方案下新鲜单囊胚移植 (SBT) 周期的临床、围产期和产科结果。方法 我们招募了在 2016 年 6 月至 2018 年 12 月期间接受早期卵泡期延长方案且 β-hCG 值高于 10 IU/L 的新鲜 SBT 周期 (n = 771) 的患者。符合纳入和排除标准的患者分为四组触发当天他们的血清 E2 水平百分比：<25th、25-50th、51-75th 和 >75th 百分位数组。结果临床妊娠率（85.57%（166/194））、胚胎植入率86.60%（168/194）、持续妊娠率（71.13%（138/194））、活产率（71. 13% (138/194)) 在 > 75% 组中最低，我们没有观察到任何显着差异（所有 P > 0.05）。我们使用这些信息来预测严重卵巢过度刺激综合征 (OHSS) 曲线下面积 (AUC) = 72.39%，P = 0.029，E2 的截止值 = 2,893 pg/ml，敏感性为 75%，特异性为 70% . 第 51-75 个百分位数组的低出生体重婴儿（11.73% (19/162)，P = 0.0408）、早产（11.43% (20/175)，P = 0.0269）、入住新生儿重症监护室的比例最高监护病房 (NICU) (10.49% (17/162), P = 0.0029), 双胎妊娠 (8.57% (15/175), P = 0.0047), 单绒毛膜双羊膜妊娠 (8.57% (15/175); P = 0.001)。我们没有观察到产科并发症的统计学差异，包括妊娠糖尿病 (GDM)、妊娠高血压、前置胎盘、胎膜早破（PROM）和胎膜早破（PPROM）。结论 我们得出结论，触发当天的血清 E2 水平并不是活产率或围产期和产科结局的良好预测指标。然而，我们发现高 E2 水平可能不利于持续妊娠。触发当天的 E2 水平仍可用于预测新 SBT 周期中早发性重度 OHSS 的发生率。