Publication:

A prospective observational study comparing two embryo-transfer catheters (metal catheter versus soft catheter) and techniques to evaluate their impact on pregnancy outcomes

Background The procedure of embryo transfer (ET) is a critical determinant of success in the field of assisted reproductive technology (ART), and the choice of transfer catheter may influence pregnancy outcomes. Although soft ET catheters are generally preferred because of their atraumatic design, metallic catheters may offer technical advantages in selected cases with challenging cervical anatomy. This prospective observational study compared pregnancy outcomes between the Edwards-Wallace soft catheter and the Easy Flex metal catheter.

Methods Thirty-two women undergoing intracytoplasmic sperm injection (ICSI)/ in vitro fertilization (IVF) treatment at Risaa IVF Centre, New Delhi, between November 2025 and May 2026 were enrolled. Patients were allocated into two equal groups (n=16 each) based on the ET catheter selected according to findings from a mock ET. Baseline demographic characteristics, ovarian reserve parameters, stimulation characteristics, embryological outcomes, and β-hCG confirmed pregnancy rates were compared. The primary outcome was a positive pregnancy test measured by serum β-hCG test performed 14 days after ET.

Results Baseline clinical characteristics, ovarian reserve markers (AFC and AMH), gonadotropin requirements, oocyte yield, fertilization rates, blastocyst formation and development, and the number of embryos transferred were same among the two groups and was statistically insignificant (p>0.05). Positive serum β-hCG test was observed in 8 of 16 patients (50.0%) in the Easy Flex metal catheter group and 7 of 16 patients (43.8%) in the Edwards-Wallace group. No statistically significant difference in pregnancy outcomes was identified between the groups (OR=1.29, p=1.000).

Conclusions The Easy Flex metal catheter and the Edwards-Wallace soft catheter demonstrated comparable clinical performance with respect to positive pregnancy outcomes following IVF/ICSI. These findings suggest that catheter selection may be guided by procedural considerations and operator preference rather than expected differences in pregnancy rates. Large scale randomized controlled trials and studies are required to validate these findings.