2007년 미국불임학회(ASRM) P-673 Retained embryos in the transfer catheter and their immediate retransfer have no adverse impact on pregnancy outcome. (배아 이식시 카테터에 배아가 남아 있는 경우 바로 재이식하여도 임신율에 부정적인 영향을 주지 않는다.)

K. H. Lee, S. G. Kim, S. J. Kim, B. R. Do.
Mamapapa & baby obstetrics and Gynecology, Ulsan, Republic of Korea.

OBJECTIVE

The aim was to assess the effect of embryo retention in the embryo transfer catheter followed by immediate retransfer on pregnancy outcome in IVF-ET.

DESIGN

The results of all embryo transfer procedures performed between April 2003 and December 2006 were analyzed retrospectively.

MATERIALS AND METHODS

842 consecutive fresh, non-donor, ultrasound-guided ETs performed on 685 patients between April 2003 and December 2006 were analyzed. The patients were classified in two groups: patients in whom a transfer was performed without retained embryos (group A; n=647) and patients in whom one or more retained embryos were found in the catheter after the transfer (group B; n=38). Implantation and clinical pregnancy rates were statistically analyzed by t - test.

RESULTS

The overall incidence of retained embryos during the study period was 5.5% (38 out of 685) following a clean initial embryo transfer. The mean age of the patients (33.8 ± 4.1 vs. 33.7 ± 3.4), mean number of retrieved oocytes (13.0 ± 7.9 vs. 11.2 ± 7.1), fertilized oocytes (8.1 ± 5.4 vs. 7.1 ± 5.0) and the embryos transferred (4.0 ± 1.1 vs. 4.1 ± 0.9) were comparable in patients with and without retained embryos. The 842 embryo transfers performed during the study period resulted in 412 pregnancies (51.3%), of which 342 proved to be ongoing pregnancies (40.6%). The implantation rate was 18.4%. Pregnancy outcomes including clinical pregnancy rates (64.1% vs. 48.2%; P< 0.01), implantation rates (23.3% vs. 18.2%; P< 0.01) and spontaneous abortion rates (28.0% vs. 16.3%; P< 0.01) were significantly higher for group B than for group A. Multiple pregnancy rates (44.0% vs. 41.4%) were not significantly different between patients with and without retained embryos.

CONCLUSION

The initial assumption of the authors has been that retained embryos would have an adverse impact on the pregnancy rate. However, our data contradicts this assumption and indicates that the clinical pregnancy rate is not compromised when embryos are retained, provided they are discovered and immediately retransferred into the uterine cavity. Immediate retransfer is more convenient for the patient and reduces the laboratory workload without compromising the treatment outcome.