Table 1 Equations calculating the daily gonadotropin dose needed for maximal oocytes’ yield

Step 1: Calculate X using the first equation (a):

X=-0.514 + 2.87*A1 + 1.733*A2–0.194* (E2/1000)

If the number of oocyte retrieved in the first cycle is < 7: A1 = 1 and A2 = 0.

If the number of oocyte retrieved in the first cycle is between 8–12: A1 = 0 and A2 = 1.

And If the number of oocyte retrieved in the first cycle is > 13, A1 = 0 and A2 = 0.

E2 is the estradiol level (pmol/L).

Step 2: After calculating the X value, it should be placed in the following logistic model (b):

P = EXP(X) / [1 + EXP(X)]

If P > 0.5 then the suggested daily gonadotropin dose in the successive cycle should be 450IU, while if P < 0.5 it should be 300IU.