Embryo transfer technique significantly influences pregnancy rates in an assisted reproduction program

Abstract

Embryo transfer has been regarded as a rather unimportant variable in IVF. Problematic embryo transfers, have been associated with low pregnancy rates. Some factors including the “physician factor”, type of catheter and insertion control may be readily modified; even intrafallopian transfers have been proposed. The aim of this study is to evaluate the influence of three different ways of embryo transfer: (1) transcervical “blind” catheterization, (2) transcervical ultrasound-guided, and (3) tubal embryo transfer (TET). Retrospective computer data base analysis. Fresh embryo transfers performed transcervically by a single physician, and tubal embryo transfers, were retrospectively analyzed from: January 2001 through December 2003. All patients had: ≤ 37 years, normal basal FSH levels, patent tubes and at least one good quality embryo (class IV or III-scale I to IV-) transferred. Study groups were: 1)(n= 45) soft catheter blind insertion; 2) (n=40) soft catheters and ultrasound (US) guidance; and 3) (n=61) laparoscopic tubal transfer. Clinical pregnancy rates, implantation rates, abortion and ectopic pregnancy rates were calculated. The three groups were comparable in terms of age, time of infertility, and diagnosis. Stimulation protocols were comparable in terms of : use of GnRH-agonists and dose of gonadotropins. Mean maximum estradiol levels were not significantly different; as well as the mean number of oocytes retrieved, fertilization rates and cleavage rates. Mean number of transferred embryos by embryo quality (best quality=IV); were also comparable (Table 1) Abortions/ectopic pregnancies rates were respectively: gr 1: 12.5%/6.25%; gr 2: 0%/0% to date; gr 3:14.6%/2.4%. Tubal embryo transfers do not yield higher pregnancy rates than the transcervical technique carefully performed, under ultrasound guidance. TET’s imply a laparoscopy, with additional morbidity, cost and time expense; and though it may avoid negative factors influencing some problematic transcervical transfers cannot be recomended as a first choice.