FSH (Follicle Stimulating Hormone)

FSH has to be measured on a specific day in the cycle (day 3 but if you miss it, anything from day 2 to 5 will work).
FSH rangeĀ on day 3 and what to expect sorted by age:
< 33 Years < 7.0 mIU/mL
33-37 Years < 7.9 mIU/mL
38-40 Years < 8.4 mIU/mL
= 41+ Years < 8.5 mIU/mL

In general, FSH under 6 marks an excellent ovarian reserve, 6-9 is good, 9-10 still OK, 10-13 means a diminished reserve, 13+ is very hard to stimulate.

The last but very important thing to remember is that FSH often oscillates in women in advanced reproductive age.

What else should be tested to estimate fertility and what ranges you should expect, you will findĀ in this post.