Top quality embryo rate according to different serum progesterone concentration cut-point on the day of hCG administration.

<p>(A) progesterone cut-point, 1.5 ng/mL; (B) progesterone cut-point, 2.0 ng/mL; (C) progesterone cut-point, 2.5 ng/mL. The TQE rate was significantly different (<i>P</i> <0.05) between serum progesterone levels < 2.0 ng/ml and >2.0 ng/ml.