The Impact of the Depth of Embryo Replacement into the Uterine Cavity under Transabdominal Ultrasound Guidance on In Vitro Fertilization and Embryo Transfer Outcome

Abstract

The aim of the present study was to determine the importance of the depth of embryo replacement into the uterine cavity (upper or lower half endometrial cavity) on the implantation clinical pregnancy rates. Material and Methods:In this prospective observational were included 160 patients underwent controlled ovarian hyperstimulation followed by IVF/ICSI and embryo transfer. On the day of embryo transfer under direct transabdominal ultrasound guidance, the transfer catheter was advanced to a defined distance from the uterine fundus, up to the point estimated for transfer: 10 ± 2.5 mm (Group A) and 15 ± 2.5 mm (Group B).Results: In total, 160 patients, aged 24-42 years were included in the study. Overall clinical pregnancy rate were 41.2%. Analysis of our results demonstrated that pregnancy rate is significantly influenced by transfer distance from the fundus where the pregnancy rate decreases from 48.7% in group B to 34.5% in group A (p<0.05). There was not significantly difference in abortion rate between the two groups. Conclusion:In conclusion, our results suggest that depth of embryo replacement inside the uterine cavity may influence the pregnancy rates and should be considered as an important factor to improve the success of IVF cycles.

Ideal embryo transfer position and endometrial thickness in IVF embryo transfer treatment

“…Although the final position of the air bubble in the endometrium cannot be predicted in advance, it can be used to predict the treatment outcomes. 8 A few studies have focused on the transfer depth, reporting that different transfer depths can affect treatment outcomes and optimal transfer depth can significantly increase success rates 8,16 ; however, the studies reached different conclusions and did not report the endometrial thickness at the transfer position. Consistent with those previous studies, a transfer depth between 10 and 20 mm led to a higher rate of implantation, pregnancy, and live delivery, and a lower frequency of spontaneous abortion, as compared with a depth of more than 20 mm in the present study.…”

Embryo Transfer in Upper Uterine Cavity versus Mid-Uterine Cavity in Cases of Previous Failed Implantation

“…The first investigated the relationship between air bubble position and pregnancy rates in 315 blastocyst transfers, but differently from our study, the EFD was measured with trans-abdominal US [11]. The PR was found to be significantly lower when the EFD was longer than 10mm [11]. The second study included 409 ETs and failed to demonstrate any significant difference in PR and IR that could be related to the site of embryo release [12].…”

“…A couple of studies using US detection of air bubble localization have been reported to date, but differently from ours they are both retrospective and include much less observations [11,12]. The first investigated the relationship between air bubble position and pregnancy rates in 315 blastocyst transfers, but differently from our study, the EFD was measured with trans-abdominal US [11].…”

“…This event has been documented by studies that demonstrated that some technical conditions of embryo transfer are associated with a relevant risk of embryo displacement [17]. In order to better assess the actual site of embryo release, the most recent publications used the US localization of the air bubble that is visible just after embryo release instead of the visualization of the catheter tip [11,12]. A large retrospective study showed that no movement of the air bubble occurs in more than 90% of cases when the catheter is loaded with a low amount of culture medium [18].…”

“…Traditionally, most IVF programs have relied on the clinician's "clinical touch" for the placing of the transfer catheter within the uterine cavity at a point near the fundus. Today this procedure has been modified to utilize ultrasound guidance to direct the placement of the catheter tip, allowing for more accurate placement [11]. It has been traditionally accepted that the embryo should be placed 10mm below the endometrial surface, but others suggest placing the embryo rather lower in the uterine cavity may improve pregnancy rate [12].…”