Background: Sub-endometrial junction zone (JZ) plays an important role in most of reproductive
functions. Objective: To find out the effect of the sub-endometrial JZ thickness assessment by 3-D transvaginal
ultrasound (TVUS) on intracytoplasmic sperm injection (ICSI) outcomes in patients with
unexplained recurrent implantation failure (RIF). Setting: ART Unit of Obstetrics and Gynecology
Department, Faculty of Medicine, South Valley University, Qena, Egypt. Duration: From April 2016 to
October 2018. Study Design: A prospective observational study. Methds: Fifty couples with history of
unexplained RIF in previous ICSI cycles and prepared for another ICSI cycle (group I) and fifty couples
with unexplained infertility prepared for ICSI for the first time (group II) had been included in this study.
At time of ovum pick up, 3-DTVUS was done for all cases in both groups for assessment of sub
endometrial junction zone thickness and correlated with ICSI outcome. Results:There were statistically
significant differences be- tween group I and group II in JZ thickness in the 3 uterine regions (fundus,
anterior and posterior walls) with p < 0.001, but there were mildly statistically significant differences
between both groups in chemical and clinical preg- nancy rates with p < 0.01. Conclusions: The
thickness of JZ in patients with history of unexplained RIF was higher than those with unexplained infertility
scheduled for ICSI. The JZ thickness was inversely correlated with increased embryo
implantation rates in ICSI procedures, the thinner the JZ thickness was associated with higher pregnancy
rates (both chemical and clinical pregnancy rates).