Notes on choosing an embryo transfer catheter

2. Factors to consider when choosing a catheter

2.1. Soft-hard characteristics

Soft catheter

Reduces the risk of damage to the endometrium and uterine contraction reflex.

The preferred choice in most clinical cases.

Rigid catheter

Convenient in cases where the cervix is ​​bent and difficult to access.

Higher risk of trauma.

Optimal solution: prepare a “dual system” catheter (hard outer sheath for guidance + soft inner catheter for embryo placement).

2.2. Catheter tip design

Smooth tip, thin bevel, small diameter helps reduce trauma.

The curved type is useful in patients with special uterine anatomy (anterior or posterior bend).

2.3. Ultrasound visibility (Echogenic tip)

Catheters with echogenic tips improve the accuracy of embryo transfer under ultrasound guidance.

HFEA (UK) recommends the use of ultrasound in ET because it is associated with a higher clinical pregnancy rate than “blind” embryo transfer.

2.4. Materials

Preferably bioinert materials (FEP – Fluoroethylene propylene, PU – Medical Polyurethane).

No release of additives, no impact on embryo microenvironment.

Need to ensure atraumatic (non-toxic, non-inflammatory).

2.5. Length & scale

Usually 23–25 cm, suitable for most patients.

Catheter with cm scale helps the doctor control the depth into the uterine cavity.

2.6. Flexibility & manipulation

Single lumen: simple, fast, suitable for easy cases.

Double lumen: has a guiding sheath, useful in difficult cervical cases or requiring multiple manipulations.

2.7. Quality & Sterility Standards

Instruments must meet CE, FDA standards.

Disposable, sterile packaging, ensuring maximum safety.

3. Clinical evidence regarding embryo transfer catheters

Studies have shown that ease of use and non-traumatic ET are directly associated with higher success rates.

Flexible catheters have been shown to result in higher clinical pregnancy rates than rigid catheters in most reports (Mansour RT et al., Hum Reprod Update, 2011).

ESHRE guidelines recommend the use of flexible catheters, with ultrasound-enabled tips, and performing embryo transfer under ultrasound guidance when possible.

4. Conclusion

Choosing an embryo transfer catheter is not only a technical issue but also a decisive factor in the success rate of IVF. Doctors need to consider:

The softness and design of the catheter tip,

Ultrasound visibility,

The biosafety of the material,

The flexibility in clinical operations.

An optimally designed catheter will help the embryo transfer process to be gentle, less traumatic, place the embryo in the right position and thereby improve the chance of pregnancy.