Measurement of endometrial and uterine vascularity by transvaginal ultrasonography in predicting pregnancy outcome during frozen-thawed embryo transfer cycles.

AIM

An appropriate endometrial condition and vascular supply are usually considered essential for implantation of an embryo. This study was performed to assess the role of endometrial and uterine vascularity status measurement in predicting pregnancy outcome during frozen-thawed embryo transfer cycles.

MATERIAL AND METHODS

A total of 70 infertile women were recruited with controlled ovarian stimulation followed by oocyte retrieval. After in vitro fertilization or intracytoplasmic sperm injection, embryos were cultured to blastocysts and blastocysts with good quality were selected for cryopreservation. After endometrial preparation, vitrified blastocysts were thawed and assisted hatching by zona dissection was performed. On the day of embryo transfer, endometrial thickness (EMT), resistance index (RI) and pulsatility index (PI) of sub-endometrial artery (SEA) and uterine artery (UA) were obtained by transvaginal sonography. The women were divided into the pregnant and non-pregnant groups, and these variables were compared between the two groups.

RESULTS

Patients' general demographic characteristics were not statistically different between the pregnant and non-pregnant groups. The overall implantation rate, clinical pregnancy rate, and ongoing pregnancy rate were 31.1%, 41.4% and 28.6%, respectively. Twenty-nine patients who conceived had average EMT, RI of SEA, PI of SEA, RI of UA, and PI of UA values of 9.15 mm, 0.91, 2.42, 0.95, and 3.37, respectively. Forty-one patients who did not conceive had average EMT, RI of SEA, PI of SEA, RI of UA, and PI of UA values of 9.31 mm, 1.01, 2.56, 0.94, and 3.00, respectively. In the two groups, none of the variables was statistically different (P > 0.05).

CONCLUSIONS

EMT and blood flow index of endometrium and uterus measured by transvaginal sonography are not an effective predictor of pregnancy outcome in frozen-thawed embryo transfer cycles.