The answer to this question depends on what type of leukemia your husband has and which chemotherapy drugs his doctor has prescribed to combat the leukemia. Leukemia is usually treated
with a combination of various chemotherapy drugs and other medications. A few of these drugs cause infertility as a side effect. For instance, cyclophosphamide (Cytoxan), often used to treat both acute lymphocytic leukemia (ALL) and chronic lymphocytic leukemia (CLL) can cause infertility. In some cases, the drugs cause permanent sterility; in other cases, sperm counts return to normal when chemo is finished.
If having children is important to you and your husband, you need to speak with his oncologist about this issue. There may be alternate chemotherapy regimens the doctor can prescribe that are less damaging to sperm production. In addition, there are sperm preservation techniques available that might allow you and your husband to get pregnant in the future.