Supplementary Table 1.

Research terms analysis (primary and secondary fields)

Key words – primary fields	Key words – secondary fields
Male infertility	Testosterone to estradiol ratio
Aromatase inhibitors	Testolactone
Hypogonadism	Anastrozole
oligozoospermia	Letrozole
Cryptozoospermia	Aromatase inhibitors side effects
Azoospermia	Bone metabolism
Serum testosterone	Osteoarticular side effects
Serum estradiol	Klinefelter’s syndrome
Sperm concentration	Obesity
Total sperm count	Randomized clinical trial
Sperm morphology	Nonrandomized clinical trial
Sperm motility