@article{Guijarro Ponce_Núñez Calonge_Núñez_2022, title={There are better parameters Diagnostics for premature luteinization than isolate value of Progesterone level or progesterone/estradiol ratio on the day of hCG administration?}, volume={39}, url={/index.php/rif/article/view/76}, abstractNote={&lt;div class=&quot;page&quot; title=&quot;Page 2&quot;&gt; &lt;div class=&quot;layoutArea&quot;&gt; &lt;div class=&quot;column&quot;&gt; &lt;p&gt;&lt;strong&gt;Introduction:&lt;/strong&gt; Both the absolute value of progesterone (P) and the progesterone/estradiol ratio (P/E) are used for the diag- nosis of early luteinization (EL), without reaching an agreement on the appropriate threshold and with very different results in terms of its predictive ability. The P/E ratio has also created a great deal of confusion between the concept of LP and low ovarian response to hyperstimulation.&lt;/p&gt; &lt;p&gt;The objective of this study is to find a parameter that is independent of the degree of ovarian response and estradiol va- lues.&lt;/p&gt; &lt;p&gt;&lt;br&gt;&lt;strong&gt;Methods:&lt;/strong&gt; We analyzed 434 consecutive IVF cycles with FSH and/or LH stimulation and pituitary down regulation with agonist or antagonists without any prior exclusion criteria to determine the mathematical relationship between progesterone and estradiol at the time prior to ovulation.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; The empirical relationship between progesterone and estradiol is established by the formula E=4P2, from which we can deduce the descriptive formulas of P=0,5E0,5, P/E=0,5E-0,5 an P2/E=0,25, being P2/E the only one that corresponds to a constant without dependence on the estradiol level and, therefore, the ideal criterion for the diagnosis of early luteinization.&lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;div class=&quot;layoutArea&quot;&gt; &lt;div class=&quot;column&quot;&gt; &lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;The progesterone2/estradiol formula is the ideal parameter for diagnosing early luteinization given its independence from the degree of ovarian response to stimu- lation.&lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt;}, number={2 Abril-Mayo-Junio}, journal={Revista Iberoamericana de Fertilidad y Reproducción Humana}, author={Guijarro Ponce, José Andrés and Núñez Calonge, Rocío and Núñez, María José}, year={2022}, month={Jul.} }