ABSTRACT

Aim: To determine the rate of success of pregnancy based on endometrial thickness and endometrial pattern at the time of ultrasound guided embryo transfer, in FET (Frozen-thawed embryo transfer) cycles.

Methods: The study was carried out by studying FET cycles in which at least one morphologically good quality blastocyst was used, it was conducted retrospectively between 2017 till 2020 at a state of the art infertility Centre. Ultrasonographic characteristics of the endometrium were noted on the progesterone supplementation, trigger, day as well as on the day of embryo transfer in each FET cycle. On the basis of endometrial thickness two groups were observed, patients having endometrial thickness <0.85 cm and those having an endometrial thickness of >0.85cm, on the trigger day. Similarly on the day of embryo transfer two groups were observed, first group had an endometrial thickness of <1.0 cm and the other group >1.0cm. All cycles selected for our study had an endometrial pattern A (Triple line pattern). Clinical pregnancy rates in different groups divided on the basis of endometrial thickness were analyzed.

Results: A total of 97 FET cycles were studied. The result shows that no significant differences in endometrial thickness were observed between the positive pregnancy group (n=14) and not pregnant group (n=14) at the time of trigger when the endometrium measured <0.85cm and no significant difference between the positive pregnancy group (n= 30) and not pregnant group (n=39) when the endometrium measured >0.85 cm, (P <0.05). Similarly no significant differences were observed in endometrial thickness between the positive pregnancy (n=17) and not pregnant group (n= 24) when the endometrium measured <1.0 cm and none in positive pregnancy group (n= 27) and not pregnant group (n=29) when the endometrium measured > 1.0 cm at the time of embryo transfer, (P <0.05).

Conclusion: According to the results of this study the analysis of endometrial thickness at the time of trigger and at embryo transfer both, showed no predicting effects on the outcome of pregnancy rate.

Keywords: clinical pregnancy rate, endometrial thickness, endometrial pattern, Frozen-thawed embryo transfer