The effect of endometrial thickness on the day of hCG administration on pregnancy outcome in the first fresh IVF/ICSI cycle

Abstract

The aim of this study was to investigate the effect of endometrial thickness (EMT) on human chorionic gonadotropin (hCG) day on in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) outcome. A retrospective study was conducted on the clinical data of 756 patients in their first fresh IVF/ICSI cycle at the Wuxi Maternity and Child Health Hospital. Compared with the pregnancy failure group, the clinical pregnancy group had more transferable embryos and good-quality embryos and had a thicker endometrium (p < 0.05). The endometrial pattern was not significantly different between the two groups. EMT was found to be an independent prognostic factor for clinical pregnancy (adjusted OR = 1.25, 95% CI: 1.15–1.36, p < 0.01). Seven hundred and fifty-six cycles were categorized into three groups upon EMT on the hCG day: group 1 (EMT < 8 mm), 2 (EMT 8–14 mm) and 3 (EMT > 14 mm). Group1 had significantly lower clinical pregnancy, embryo implantation and live birth rates compared with group 2 and 3 (p < 0.01), while there was no significant difference in either spontaneous abortion or multiple-birth rate among these three groups. It was concluded that EMT on the hCG day was associated with pregnancy outcome in the first fresh IVF/ICSI cycle. A higher clinical pregnancy rate could be achieved when EMT ≥ 8 mm, and no adverse pregnancy outcome was observed when EMT > 14 mm.

Chinese abstract

本研究的目的是：探讨首次IVF/ICSI时，注射hCG日子宫内膜厚度(EMT)对妊娠结局的影响。回顾性研究了756例无锡妇幼保健院的首次行IVF / ICSI患者的临床资料。相比之下，临床妊娠组较妊娠失败组有更多可移植胚胎以及高质量胚胎，且有更厚的子宫内膜(p<0.05)。子宫内膜的类型两组之间没有明显不同。EMT被认为是一个独立的临床妊娠预后因子(标准OR=1.25，95%置信区间CI:1.15 - -1.36，p<0.01)。756个研究对象依据注射hCG当天子宫内膜的厚度分为三组:1组(EMT<8mm)，2组(EMT 8 – 14mm)和3组(EMT>14mm)。1组临床妊娠率、胚胎着床率以及婴儿安全出生率与2组和3组比明显降低(p<0.01)，而在自然流产率或多胎率三组没有显著差异。据此得出结论：首次IVF/ICSI时，注射hCG日子宫内膜厚度对妊娠结局有影响。当EMT≥8mm时临床妊娠率会更高，EMT>14mm时没有观察到不良妊娠结局。

• Clinical pregnancy rate
• endometrial pattern
• endometrial thickness
• fresh IVF/ICSI cycle
• pregnancy outcome

Acknowledgements

We thank all the patients who agreed to participate in this study and the nursing and medical staffs for their assistance.

Declaration of interest

This study was supported by grants from the Wuxi Municipal Hospital Management Centre (grant number YGZXM1407) and from the Science and Technology Department of Jiangsu Province (grant number BK20131094). All the funders had no role in the design, analysis, or writing of this article. The authors declare that they have no conflicts of interest.

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