Expression of vascular endothelial growth factor-A and its receptor-1 in a luteal endometrium in patients with repeated in vitro fertilization failure

Objective

To investigate temporal and spatial relationships of vascular endothelial growth factor (VEGF)-A and its receptor (VEGFR-1) expression in a luteal endometrium obtained from patients with repeated IVF failure.

Design

Immunohistochemical study.

Setting

University hospital.

Patient(s)

Thirty-three regular-cycling infertile women (mean age, 34.4 years) who experienced three or more failed IVF cycles (range, 3–14 cycles).

Intervention(s)

Endometrial samplings by silastic suction curette in the luteal phase of a spontaneous unmedicated cycle.

Main Outcome Measure(s)

Immunohistochemical intensity scoring after staining by monoclonal anti-VEGF-A and polyclonal anti-VEGFR-1. Microvascular density determined after staining by monoclonal anti-CD31 antibody. The data were compared in three phases; early (cycle day [CD]16–19) (n = 12), mid- (CD20–24) (n = 13), and late luteal phase (CD25–27) (n = 8).

Result(s)

Expression of VEGF-A tended to be lower in midluteal endometrium at epithelial, stromal, and endothelial cells. Expression of VEGFR-1 at epithelial cells was highest in midluteal endometrium, but VEGFR-1 at stroma and endothelium and microvascular density continuously decreased throughout luteal-phase endometrium.

Conclusion(s)

In contrast to previous reports, VEGF-A expression was not highest in the midluteal phase in repeated IVF failure patients who had no apparent endometrial pathology. Further research is needed to determine whether different VEGF-A expression patterns in the luteal phase contribute to repeated IVF failure.

Key Words: Vascular endothelial growth factor, repeated implantation failure, IVF, human endometrium