The feasibility of a less invasive method to assess endometrial maturation-comparison of simultaneously obtained uterine secretion and tissue biopsy

To compare the assessment of endometrial maturation parameters in endometrial secretion samples obtained by a novel minimally invasive technique with those assessed in tissue biopsies. Prospective study. University Hospital. Healthy female volunteers attending a gynaecological outpatient clinic. Endometrial secretion fluid and tissue sampling 5 days after a spontaneous ovulation assessed with ultrasound. Progesterone (P) receptor, Ki-67 expression and the Noyes criteria were used to date endometrial biopsies. In the endometrial fluid samples, glycodelin A (GdA), leukaemia inhibitory factor (LIF) and P levels were analysed, and protein content and electrophoresis patterns were determined. All data were correlated to estradiol (E-2) and P serum concentrations. The dating according to histology and immunohistochemical staining patterns correlated significantly with GdA levels (r = 0.376, P = 0.048) in endometrial fluid samples as well with serum levels of E-2 (r = 0.568, P = 0.001) and P (r = 0.408, P = 0.023). No correlation was observed between tissue dating and LIF levels and protein content in endometrial fluid samples. The measurement of GdA in endometrial secretion samples may provide a less invasive method for assessing endometrial maturation in potential conception cycles without disrupting implantation.