Evaluation of endometrial-subendometrial blood flow measured by transvaginal ultrasound in hormone replacement cycle on outcome of embryo transplantation

Objective  To explore the value of the intrauterine thickness, endometrial-subendometrial blood flow detected by transvaginal ultrasound at endometrial transformation day in the evaluation of pregnancy outcome in infertility patients underwent embryo transplantation in hormone replacement cycle.

Methods  The data of 100 patients underwent embryo transplation (ET) with hormone cycle control membrane were retrospectively analyzed. The patients were divided into pregnancy group (n=60) and non-pregnancy group (n=40). The endometrial thickness, endometrial-subendometrial blood flow indexes such as pulsatility index (PI), resistance index (RI), ratio of systolic peak velocity and end-diastolic velocity (S/D) were detected at the day of endometrium transformation. According to the result of pregnancy outcome, all patients were divided into pregnancy group and non-pregnancy group, and the differences in the various parameters between the two groups were compared.

Results  There was no significant difference between the levels of estradiol (E2), luteinizing hormone (LH), follicular stimulating hormone (FSH), and the number of high-quality embryos between the two groups at transformation day. There was no significant difference in endometrial thickness between the two groups at transformation day. Compared with the non-pregnancy group, the endometrial-subendometrial hemodynamic parameters such as PI, RI, and S/D in the pregnancy group were significantly reduced at transformation day (P < 0.05). The pregnancy rate was significantly lower in patients with endometrial thickness < 8 mm than those of endometrial thickness ≥ 8 mm at the transformation day (P < 0.05). The proportion of patients with S/D>3 in the pregnancy group was significantly lower than that in the non-pregnancy group at the transformation day (P < 0.05).

Conclusions  The endometrial thickness, endometrial-subendometrial blood flow detected at endometrial transformation day by transvaginal ultrasound are helpful to predict the outcome of embryo transplantation in hormone replacement cycle.