Alterations of Uterine Blood Flow During the Follicular Phase in Patients With Recurrent Implantation Failure: A Doppler Ultrasonographic Study

The dynamics of blood flow in the endometrium plays a crucial role during the implantation process. This study aimed to assess the uterine perfusion during the follicular phase in patients with a history of recurrent implantation failure (RIF) and healthy fertile women using the transvaginal ultrasound color Doppler method.

To this end, 50 patients with RIF and 50 age-matched healthy fertile women were recruited in this casecontrol study. The transvaginal color Doppler ultrasonography was used to evaluate the pulsatility index (PI) and resistance index (RI) of the uterine, arcuate, and sub-endometrial arteries during the follicular phase in both groups.

The RI and PI of both right and left uterine arteries were higher in the RIF group compared to the fertile women (P<0.05). Our results showed that the PI and RI of sub-endometrial blood flow and the RI of arcuate arteries were substantially higher in the group with a history of RIF in comparison with the control group. However, the PI of arcuate arteries was not significantly different between the groups.

Adequate uterine perfusion and sub-endometrial blood flow are necessary to achieve successful implantation and pregnancy since our results demonstrated the higher resistance of uterine and sub-endometrial arteries in patients with a history of RIF. Thus, the assessments of uterine perfusion indices during the follicular phase could be used as a non-invasive method in the evaluation of patients with RIF.