Assessment of the late proliferative phase endometrium by ultrasonography in patients undergoing in-vitro fertilization and embryo transfer (IVF/ET)

This study reports on 330 women aged 29 to 45 years, who underwent 411 cycles of in-vitro fertilization and embryo transfer (IVF/ET). Vaginal sonograms were performed during the late proliferative phase of natural cycles and cycles of controlled ovarian hyperstimulation (COH) with gonadotrophins, to evaluate both the thickness and echogenicity of the endometrium. Findings classified as Grade I; characterized by homogeneous echogenicity of the endometrium, and Grade II; characterized by an outer peripheral layer of dense echogenicity surrounding a central sonolucent area (i.e. a 'halo pattern'). Grades I and II were subclassified on the basis of thickness into A (greater than or equal to 9 mm) and B (less than 9 mm). Grade IIA ('optimal') was associated with a clinical pregnancy rate per embryo transfer of 33% while Grades IA, IB and IIB ('poor') were associated with a rate of only 7%. Women aged 41-45 years experienced a 25% incidence of 'poor' sonographic grades while the incidence in women less than or equal to 40 years of age was 5%. The presence of various uterine pathologies was associated with 'poor' endometrial grades in 86% of cases while only 11% of normal uteri manifested 'poor' grades. 'Optimal' endometrial grades in natural cycles were consistently associated with 'optimal' grades in ensuing cycles of COH (96%). Women with 'poor' endometrial grades in natural cycles improved in 55% of cases during subsequent COH. The results of this study indicate that sonographic assessment of the endometrial lining in the late proliferative phase during both natural and COH cycles is a valuable method for screening and managing IVF/ET candidates.