P4越早上升，胚胎著床率越低

P4在誘導排卵過程中越早上升(>1 ng/ml)(，子宮內膜對於胚胎著床率越低

http://humrep.oxfordjournals.org/content/27/7/2036.full

Figure 1

The association between the duration of pre-hCG P elevation (>1 ng/ml) and clinical pregnancy rate calculated by multivariate logistic regression analysis. The duration of pre-hCG P elevation was divided into three groups (0 day, 1–2 and ≥3 days). The confounding factors adjusted for include age (years), the number of retrieved oocytes, the number of transferred embryos and good embryo rate (%). (A) The overall clinical pregnancy rate is significantly decreased with a longer duration of serum P elevation before hCG administration (P < 0.001). (B–D) This remains true irrespective of the down-regulation protocol. (B) GnRHa short protocol: P < 0.001, n = 927. (C) GnRHa antagonist protocol: P < 0.001, n = 499. (D) GnRHa long protocol: P= 0.001, n = 358.