Combined analysis of endometrial thickness and pattern in predicting clinical outcomes of frozen embryo transfer cycles with morphological good-quality blastocyst: A retrospective cohort study

Abstract

To evaluate the combined effect of endometrial thickness and pattern on clinical outcomes in females following in vitro fertilization/intracytoplasmic sperm injection and frozen-thawed embryo transfer (IVF/ICSI-FET).FET cycles using at least 1 morphological good-quality blastocyst conducted between 2012 and 2013 at a university-based reproductive center were reviewed retrospectively. Endometrial ultrasonographic characteristics were recorded on the day of progesterone supplementation in FET cycles. In the combined analysis, endometrial thickness groups (group 1: equal or < 8 mm; group 2: >8 mm) were subdivided into 2 endometrial patterns (pattern A: triple-line; pattern B: no-triple line). Clinical pregnancy rate, spontaneous abortion rate, and live birth rate in different groups were analyzed.A total of 1512 cycles were reviewed. The results showed that significant differences in endometrial thickness and pattern were observed between the pregnant group (n = 1009) and no pregnant group (n = 503) (P < .05), while no significant differences were found between the live birth group (n = 844) and no live birth group (n = 668). Combined analysis revealed those with endometrial thickness > 8 mm and triple-line endometrial pattern had significant higher clinical pregnancy rates, while spontaneous abortion rates and live birth rates showed no significant differences among these subgroups.This study suggested neither individual nor combined analysis of endometrial thickness and pattern had predicting effects on live birth following IVF treatments, and embryo quality might be the one that really has effects.

Figure 1

Receiver operator characteristic curve (ROC) of endometrial thickness during FET cycles (endometrial thickness and clinical pregnancy). (A) The clinical pregnancy following frozen-thawed blastocyst embryo transfer cycles. (B) The live birth following frozen-thawed blastocyst embryo transfer cycles. FET = frozen blastocyst embryo transfer, ROC = receiver operating characteristic curve.

Figure 2

Relationship between endometrial thickness and pregnancy outcomes in 1512 frozen-thawed blastocyst embryo transfer cycles.

Figure 3

The relationship between clinical outcome and endometrial thickness and pattern. Endometrial thickness: Group 1: ≤8 mm; Group 2: >8 mm. Pattern A = triple-line pattern, hypoechoic endometrium with well-defined hyperechoic outer walls and central echogenic line; Pattern B = no-triple line pattern, isoechogenic or homogeneous hyperechoic endometrium with a poorly defined or absent central echogenic line.