Firm versus soft embryo transfer catheters under ultrasound guidance: Does catheter choice really influence the pregnancy rates?

Performing the embryo transfer: a guideline

“…The majority of the literature, including 10 RCTs and 1 cohort study, shows no difference in IVF outcomes (clinical pregnancy rate, pregnancy rate, implantation rate) when comparing different types of soft catheters (81)(82)(83)(84)(85)(86)(87)(88)(89)(90)(91). A single RCT and one cohort study favored the Edwards-Wallace catheter compared with rigid catheters when looking at pregnancy rate (92,93). None of the trials included demonstrated a difference in birth rates when comparing soft catheters to one another.…”

Practice of Embryo Transfer: Recommendations During and After

“…36 Another study found that the choice of the catheter did not significantly affect the clinical PRs in IVF when it is performed under US guidance or after mock transfer. 37,38 Likewise, a prospective randomized clinical trial that included 150 women undergoing fresh ET demonstrated that the type of ET catheter did not significantly influence the clinical PR because there was no significant difference in the clinical PRs between Wallace and Cook catheters. 39 As a result, the choice of ET catheter may be decided by its cost and mostly by operator's preference.…”

Does Placement of the Catheter Guide Through the Cervical Canal Influence the Embryo Transfer Outcome?

“…ET catheter properties vary in several ways, such as design, presence of an outer sheath, and quality [11]. While some studies have supported the benefit of one catheter type over another in terms of pregnancy rates [17][18][19], other studies found no significant difference between the catheters [7][8][9]20,21]. Meanwhile, the position of the tips has been evaluated by some researchers, leading to the suggestion that they be placed at least 5 mm from the fundus, without touching it [22,23].…”

“…On the other hand, a perfect ET technique remains controversial as a result of studies reporting different effects of many factors, such as the type of catheter, blood at the catheter tip, easy or difficult transfer, ultrasound-guided transfer, uterine contractions, and also physician factor [5,6]. Among these critical steps, during embryo transfer, the type and placement of the tip of the catheter have recently been studied by many clinicians to determine their effect on pregnancy rate [7][8][9][10]. However, the ideal position of the catheter guide related to the cervical canal has been of little interest.…”