My DH also has a low sperm count. You can try IUIs, IVF w/ ICSI. Natural things you can try are FertilAId for men ( I have 2 friends who conceived w/ these vitamins and TTC naturally) and Instead Cups (can buy at walgreens). Do you know if your DH has a varicocele? If so some men have a dramatic improvement w/ the surgery for that. Good LUCK to you : )
There are also things you can do, like he should avoid them getting hot (particularly things like putting a laptop on his lap), eating foods rich in antioxidants, improving his overall health.
If low, but not too low, IUI may also be an option.
How low is low? If you know this is a problem, have you or your husband discussed this with the doctor? Low sperm count can only be diagnosed by medical tests, how would you have gotten that far and not gotten some advice from a doctor? There are things that can be tried, but it's hard to advise without knowing what you have tried.
If you go the ivf route they can do icsi--where they inject one sperm into each egg. You don't need many sperm for that!