Objective-Given the importance of ET technique during assisted reproductive technology cycles, we evaluated the effect of embryo afterloading subsequent to placement of the ET catheter on pregnancy rates vs. a standard direct ET.
Design-Retrospective cohort analysis.
Setting-University-based assisted reproductive technology program.Patient(s)-Patients undergoing a fresh nondonor day 3 ET by a single provider over a 1-year period.
Intervention(s)-None.
Main Outcome Measure(s)-Clinical pregnancy.Result(s)-One hundred twenty-seven patients met inclusion criteria, and the overall pregnancy rate was 46.5%. There was no difference between the two groups with respect to age, basal FSH, or number of embryos transferred. The ET method used was at the discretion of the provider. There was no difference between the two groups in the presence of blood on the transfer catheter. However, there were significantly more transfer catheters with mucus contamination in the direct transfer group (25.58% vs. 5.95%). The clinical pregnancy rate in the group with ET using the afterloading technique was higher than in the direct ET group (52.4% vs. 34.9%).
Conclusion(s)-There was a trend toward an increase in pregnancy rate when an embryo afterloading technique was used. A prospective randomized trial is needed to examine this issue. Technology reported an increase in live birth rates from 28% in 1996 to 32% in 2002 (1). This increase has been attributed to multiple factors including improved stimulation protocols (2-4), advances in embryology laboratory techniques (5), and improvement in ET techniques (6, 7).
KeywordsEmbryo transfer is universally accepted as a crucial last step in any ART cycle. The importance of this step has been emphasized by the fact that different providers at the same institution may have disparate pregnancy rates after ET (8,9). Other variables affecting pregnancy include the ease of ET (7, 10, 11), presence or absence of blood on the transfer catheter (12), type of catheter used (13), technique used to perform the transfer (14-16), and experience of the physician (17).In the early 1990s, studies were first published on the use of a mock or "dummy" ET before the start of an IVF cycle (11,18). A mock ET allows the physician to choose the appropriate transfer catheter, measure the depth of the endometrial cavity, and anticipate potential problems at ET. However, a mock transfer remote from the actual ET is done under different circumstances and may not be reflective of actual conditions encountered on the day of ET. Sharif et al. (19) proposed to circumvent this problem by performing a mock ET immediately before the actual ET.To avoid additional trauma by the passage of two separate catheters, we began transferring embryos by an afterload technique, in which an empty catheter is placed at, or just past, the internal cervical os. The inner sheath is withdrawn, and a second inner sheath containing the embryos is passed. This gives the provider the benefit of an immediate mock transfer while minimizing mani...
