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Updated: Jul 17, 2026
Contrast Imaging in Mouse Embryos Using High-frequency Ultrasound
Published on: March 4, 2015
Ultrasound-guided embryo transfer does not offer any benefit in clinical outcome: a randomized controlled trial
I P Kosmas1, R Janssens, L De Munck
1Centre for Reproductive Medicine, Dutch-Speaking Brussels Free University, Brussels, Belgium. kosmasioannis@gmail.com
Background:
Ultrasound-guided embryo transfer (ET) is widely suggested as a standard clinical practice that improves overall embryo implantation and pregnancy rates. Various studies of this issue suffer from methodological pitfalls, so that a randomized controlled trial, which overcomes these problems, might be valuable.
Methods:
Three hundred women aged <40, who underwent fresh ET, were included in this randomized, double-blind controlled trial. The K-J-SPPE echo tip soft catheter was used for the ultrasound-guided ET and the traditional K-Soft catheter for ETs not using ultrasound. One experienced operator performed all ETs. The primary study outcome was overall pregnancy rate (defined as the number of positive hCG results per transfer).
Results:
No significant differences between groups were found regarding baseline patient and embryological characteristics, except for male factor and unexplained infertility (higher in the blind and ultrasound-guided ET group, respectively, P < 0.05). Overall pregnancy rates were 53.3 and 51.3% in the ultrasound-guided and blind ET group, respectively. Two ectopic pregnancies were reported in each group. Difficulty in cervical negotiation did not differ between the two groups.
Conclusions:
In patients undergoing ET by an experienced operator, ultrasound guidance did not provide any benefit in terms of overall clinical pregnancy and embryo implantation rates.
