There are lot of people with DOR. I know a women whom got pregnant with twins. But both stopped developed and she had miscarriage. Her AFC was 11 and she had 6 follicles. There are lot of people who got succes eventhough there numbers are low.

Low sperm count could be due to Structural abnormalities, Testicular injuries/trauma, Infections such as mumps virus, Environmental and lifestyle factors.

if your bother not checked all these, please ask your brother check all these.