High pre-treatment serum sLHCGR and LH-sLHCGR reduce embryo implantation. The serum sLHCGR (a & b) and LH-sLHCGR (c & d) concentrations were plotted for patients yielding ≥ 15 oocytes (a & c) and < 15 oocytes (b & d). Each data set was plotted in duplicate (open circle and triangle), where extremely high values (open circle) in each data set were excluded (open triangle) in order to compare the data representing > 90% of the patients. The cut-off values for a) and b) were 50 and 100 pmol/mL, respectively and for c) and d) were 10 and 20 pmol/mL, respectively. The bar indicates the mean value for each condition below the cut-off values. The level of significance (P values) determined by comparing different groups are shown. NP, Not pregnant; P, Pregnant.