Hubby’s fertility off, mine is normal

Savvy

My hubby and I have been TTC for 18 months or so without success. Both have had work ups by our doctors. Turns out it’s not me having the issues it’s him. Now he’s having to go to an endocrinologist for testing after seeing PCP and a urologist. Sperm count is low, low testosterone level. Anyone else have a partner who’s going through this or have came out the other side of this with positive outcome?