A total of 42,132 fresh cycles between 1 January 2013 and 31 December 2019 were included in this retrospective cohort study. Data were collected from five reproductive centers of large academic or university hospitals in China. All patients were divided into different groups according to their endometrial thickness on hCG trigger day. Multivariate regression analysis, curve fitting and threshold effect analysis were performed.
After adjusting for age, body mass index, infertility type, number of embryos transferred, number of retrieved oocytes and COS (controlled ovarian stimulation) protocols, significant associations were found between endometrial thickness and clinical pregnancy rate (adjusted odds ratio [aOR]: 1.05; 95% confidence interval [CI]: 1.06-1.08, P < 0.0001), live birth rate (aOR: 1.04; 95% CI: 1.03-1.05, P < 0.0001) as well as miscarriage rate(aOR: 0.96; 95% CI: 0.94 - 0.98, P < 0.0001). When the endometrial thickness was less than 12mm, the clinical pregnancy rate and live birth rate were increased significantly by 10% and 9%(OR:1.10; 95%CI: 1.08-1.12, OR:1.09; 95%CI: 1.07-1.11), respectively, along with the increase of each millimeter increment of endometrial thickness. However, when the EMT ranged from 12-15 mm, were stable at the ideal level, that were not significantly associated with EMT growth. Additionally, clinical pregnancy rate and live birth rate were slightly reduced by 6% and 4% when EMT was ≥15mm. Meanwhile, the miscarriage rate was significantly declined by 8% (OR:0.92; 95%CI: 0.90-0.95)with each millimeter increment of EMT. And when EMT was thicker than 12mm, the miscarriage rate didn\'t change any more significantly.
Endometrial thickness exhibits a curvilinear relationship with pregnancy outcomes in fresh embryo transfer cycles. Clinical pregnancy rate, live birth rate and miscarriage rate may achieve their optimal level when EMT ≥ 12 mm, but some adverse pregnancy outcomes would be observed when EMT ≥15 mm especially for clinical pregnancy.
本回顾性队列研究共纳入2013年1月1日至2019年12月31日期间的42,132个新鲜周期。数据来自中国大型学术或大学医院的五个生殖中心。根据hCG触发日子宫内膜厚度将所有患者分为不同的组。多元回归分析,进行曲线拟合和阈值效应分析.
调整年龄后,身体质量指数,不孕类型,移植的胚胎数量,回收的卵母细胞数量和COS(控制性卵巢刺激)方案,发现子宫内膜厚度与临床妊娠率之间存在显着相关性(调整比值比[aOR]:1.05;95%置信区间[CI]:1.06-1.08,P<0.0001),活产率(aOR:1.04;95%CI:1.03-1.05,P<0.0001)和流产率(aOR:0.96;95%CI:0.94-0.98,P<0.0001)。当子宫内膜厚度小于12mm时,临床妊娠率和活产率分别显著增加10%和9%(OR:1.10;95CI:1.08-1.12,OR:1.09;95CI:1.07-1.11),分别,随着子宫内膜厚度每毫米的增加而增加。然而,当EMT范围为12-15毫米时,稳定在理想水平,与EMT生长无显著相关性。此外,当EMT≥15mm时,临床妊娠率和活产率分别略微降低6%和4%。同时,EMT每增加1毫米,流产率显着下降8%(OR:0.92;95CI:0.90-0.95).当EMT厚于12mm时,流产率没有明显变化。
在新鲜胚胎移植周期中,子宫内膜厚度与妊娠结局呈曲线关系。临床妊娠率,当EMT≥12mm时,活产率和流产率可能达到最佳水平,但当EMT≥15mm时,尤其是临床妊娠时,会出现一些不良妊娠结局.