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Transfer of embryos into the uterus: how much do technical factors affect pregnancy rates?
T al-Shawaf1, R Dave, J Harper
1London Fertility & Gynaecology Centre, England.
Objective:
Our objective was to identify the effect on outcome of (a) ultrasound-assisted embryo transfer, (b) the use of different embryo transfer catheters, and (c) the length of time the patients remain in the supine position after embryo transfer.
Setting:
The setting was a private fertility center.
Subjects:
This was a prospective study of 178 in vitro fertilization and embryo transfers (IVF-ET) and 63 frozen embryo replacements (FER).
Results:
The pregnancy rate was 28.7% following IVF-ET and 31.8% for FER. Ultrasound-assisted transfer did not affect the outcome (29 vs 30.3%). There was no difference in the performance of the Wallace and Frydman catheters with regard to outcome (30.3 vs 30.7%). Although there was an increase in pregnancy rate as the time interval in the supine position after ET increased, this needs a larger study.
Conclusion:
The parameter studies did not affect the outcome of IVF/ET or FER. Some factors encouraged us to recommend ultrasound-assisted transfer in some cases, and the use of a Frydman catheter for transfer and to encourage the supine position after transfer for longer periods.
