Cervical dilatation has a positive impact on the outcome of IVF in randomly assigned cases having two previous difficult embryo transfers

BACKGROUND: The difficulty of embryo transfer has been reported to affect success rates in some centres, but not in others. Cervical dilatation has been proposed as a means to overcome difficult embryo transfer, but consistent criteria for patient selection are lacking. In a prospective randomized study, we examined the influence of cervical dilatation 1-3 months before embryo transfer on the outcome of IVF in cases having difficult embryo transfer in two previously failed IVF cycles. METHODS: Two alternative methods of embryo transfer preparation were evaluated in 283 randomly assigned women having difficult embryo transfers in two previously failed IVF attempts. Randomization was made using a computer-generated random number table. Cervical dilatation before starting any IVF treatment was used in 145 cases, and no dilatation was performed in 138 cases. RESULTS: The cervical dilatation group yielded a significantly higher pregnancy rate than the non-dilated group (40% versus 24%; P < 0.01). Likewise, the implantation rate (24.1% versus 14.9%; P < 0.01) and the live birth rate (34.48% versus 19.56%; P < 0.01) were significantly higher in the dilatation group than in the non-dilated group. CONCLUSIONS: In patients with prior difficult embryo transfer, cervical dilatation 1-3 months before embryo transfer lead to an improved pregnancy rate.