Patient selection: infertile woman with normal FSH levels
Parameters (with data limits):
(1) body mass index in kg per square meter, BMI (from 0 to 12)
(2) free androgen index, FAI (from 0 to 12)
(3) oligomenorrhea vs amenorrhea
(4) age in years (from 20 to 40)
Steps:
(1) Determine chance of ovulation based on FAI, BMI and oligo/a-menorrhea
(2) Determine chance of live birth based on chance of ovulation (from 1), age and oligo/a-menorrhea.
The combinations from the nomogram on page 96 were determined and the findings analyzed in JMP. The following equations were obtained as reasonable approximations for the data.
Chance of Ovulation – Oligomenorrhea
chance of ovulation =
= ((slope) * BMI) + (intercept)
slope =
= (-0.077088 * (FAI)) – 0.50978
intercept =
= (-0.07045 * ((FAI)^2)) + (0.96649 * (FAI)) + 105.9835
Chance of Ovulation – Amenorrhea
chance of ovulation =
= ((slope) * BMI) + (intercept)
slope =
= (0.0060919 * ((FAI)^2)) - (0.094334 * (FAI)) – 1.166901
intercept =
= (-0.196434 * ((FAI)^2)) - (0.249061 * (FAI)) + 109.65297
Chance of Live Birth – Oligomenorrhea
chance of live birth =
= ((second order value) * ((age)^2)) + ((first order value) * (age)) + intercept
second order value =
= (0.0008481 * (chance of ovulation)) + 0.000273
first order value =
= (-0.08111 * (chance of ovulation)) – 0.012569
intercept =
= (1.9665478 * (chance of ovulation)) + 0.1826
Chance of Live Birth – Amenorrhea
chance of live birth =
= ((second order value) * ((age)^2)) + ((first order value) * (age)) + intercept
second order value =
= (0.0004533 * (chance of ovulation)) + 0.0041528
first order value =
= (-0.059916 * (chance of ovulation)) – 0.274882
intercept =
= (1.8324987 * (chance of ovulation)) + 4.7478313
