Will chemotherapy make me infertile or cause me problems fathering a child?

Yes. Chemotherapy can be even more damaging when patients are at the later part of their reproductive years. Ask your oncologist for a referral to a fertility specialist who can offer treatments such as egg and/or embryo preservation before you begin chemotherapy.
It could. Many chemotherapy agents affect rapidly dividing cells, including sperm production cells. Seek the advice of a fertility expert (reproductive endocrinologist) if you are facing chemotherapy. Good options for fertility preservation are available.