Methodology of human embryo transfer following assisted reproduction

Soft versus firm embryo transfer catheters for assisted reproduction: a systematic review and meta-analysis*

BACKGROUND

The true impact of the embryo transfer catheter choice on an IVF programme has not been fully examined. We therefore decided to systematically review the evidence provided in the literature so that we may evaluate a single variable in relation to a successful transfer, the firmness of the embryo transfer catheter.

METHODS

An extensive computerized search was conducted for all relevant articles published as full text, or abstracts, and critically appraised. In addition, a hand search was undertaken to locate any further trials.

RESULTS

A total of 23 randomized controlled trials (RCT) evaluating the types of embryo transfer catheters were identified. Only ten of these trials, including 4141 embryo transfers, compared soft versus firm embryo catheters. Pooling of the results demonstrated a statistically significantly increased chance of clinical pregnancy following embryo transfer using the soft (643/2109) versus firm (488/2032) catheters [P = 0.01; odds ratio (OR) = 1.39, 95% confidence interval (CI) = 1.08-1.79]. When only the truly RCT were analysed, the results were again still in favour of using the soft embryo transfer catheters [soft (432/1403) versus firm (330/1402)], but with a greater significance (P < 0.00001; OR = 1.49, 95% CI = 1.26-1.77).

CONCLUSION

Using soft embryo transfer catheters for embryo transfer results in a significantly higher pregnancy rate as compared to firm catheters.

The choice of embryo transfer catheter affects embryo implantation after IVF

OBJECTIVE

Comparison of two transfer catheters in an IVF program.

DESIGN

Prospective, randomized clinical study.

SETTING

A private tertiary care center for ART.

PATIENT(S)

66 patients < 38 years of age undergoing IVF and/or ICSI.

INTERVENTION(S)

Patients were randomly assigned to undergo ET using the Tomcat catheter (n = 32) or the TDT catheter (n = 34).

MAIN OUTCOME MEASURE(S)

Primary outcome measures were implantation and pregnancy rates. Secondary outcome measures were contamination with blood and/or mucus on the tip of the catheter, cramping or patient discomfort, and time required to complete ET.

RESULT(S)

Use of the Tomcat catheter resulted in significantly higher implantation (25.2% vs. 8.4%) and clinical pregnancy rates (47% vs. 14.7%) compared with the TDT catheter. All secondary outcome measures were similar for both catheters.

CONCLUSION(S)

The choice of ET catheter may affect the success of IVF-ET cycles. Use of the Tomcat catheter compared with the TDT catheter seems to result in significantly better efficiency of the ET procedure and is more cost effective.