OBJECTIVE: The purpose of this study was to assess the receptivity of the homogeneous endometrium in the late follicular phase in infertile women with natural cycles. STUDY DESIGN: Twenty-eight infertile women with ultrasonographically homogeneous (group 1) or trilaminar (group 2) endometria in the late follicular phase underwent endometrial biopsies. Some molecular markers and development of pinopodes were evaluated. RESULTS: In the late follicular phase, the mean level of vascular endothelial growth factor was significantly lower in group 1 than in group 2 (0.96 ± 0.37 marks vs 1.39 ± 0.46 marks; P = .010). In the mid luteal phase, a decreased leukemia inhibitory factor and integrin alpha v beta 3 levels were found in group 1 (1.58 ± 0.99 marks vs 2.59 ± 0.61 marks; 1.85 ± 0.72 marks vs 2.60 ± 0.73 marks; 1.92 ± 0.91 marks vs 2.83 ± 0.57 marks; P = .003; P = .011; P = .004). The rate of fully developed pinopodes in the mid luteal phase was significantly decreased in group 1 (P = .018). CONCLUSION: An ultrasonographically homogeneous endometrium in the late follicular phase was associated with poor receptivity in infertile women with natural cycles.
OBJECTIVE: The purpose of this study was to assess the receptivity of the homogeneous endometrium in the late follicular phase in infertile women with natural cycles. STUDY DESIGN: Twenty-eight infertile women with ultrasonographically homogeneous (group 1) or trilaminar (group 2) endometria in the late follicular phase underwent endometrial biopsies. Some molecular markers and development of pinopodes were evaluated. RESULTS: In the late follicular phase, the mean level of vascular endothelial growth factor was significantly lower in group 1 than in group 2 (0.96 ± 0.37 marks vs 1.39 ± 0.46 marks; P = .010). In the mid luteal phase, a decreased leukemia inhibitory factor and integrin alpha v beta 3 levels were found in group 1 (1.58 ± 0.99 marks vs 2.59 ± 0.61 marks; 1.85 ± 0.72 marks vs 2.60 ± 0.73 marks; 1.92 ± 0.91 marks vs 2.83 ± 0.57 marks; P = .003; P = .011; P = .004). The rate of fully developed pinopodes in the mid luteal phase was significantly decreased in group 1 (P = .018). CONCLUSION: An ultrasonographically homogeneous endometrium in the late follicular phase was associated with poor receptivity in infertile women with natural cycles.