MULTIPLE ATTEMPTS AT EMBRYO-TRANSFER - DOES THIS AFFECT IN-VITRO FERTILIZATION TREATMENT OUTCOME

In this study, we retrospectively analysed data from 877 patients who had 1204 embryo transfer procedures following in-vitro fertilization ( IVF) at Midland Fertility Services, UK, between January 1991 and Decem ber 1995 to investigate the factors contributing to failure of embryo transfer at first attempt and the impact of immediate retransfer of re tained embryos on the treatment outcome, Embryos were significantly mo re likely to be retained when the embryo transfer catheter was contami nated with mucus (3.3 versus 17.8%, P = 0.000001) or blood (3.3 versus 12%, P = 0.00001) and when the transfer procedure was difficult compa red with when it was easy (20.3 versus 0.8%, P = 0.00001), There was n o significant difference in the clinical pregnancy rate between those who had all their embryos transferred at the first attempt (24.7%) and those who required more than one attempt (23.2%). The types of embryo transfer catheter used in the unit did not show any difference in ter ms of embryo retention, Although we recommend aspiration of cervical m ucus in order to reduce the rate of retained embryos, there is no evid ence from our study to suggest that pregnancy rate is compromised when embryos are retained, provided they are discovered and immediately re transferred into the uterine cavity, Immediate retransfer is more conv enient to the patients and reduces the laboratory workload without com promising the treatment outcome.