Secondary infertility can be traced to either partner or both partners. About one-third of cases originate in women and about one-third originate in men. In the remaining one-third, the cause is due to a combination of factors or isn’t known. Increased age, complications from a prior pregnancy or surgery, increased weight, medications, sexually transmitted diseases, impaired sperm production, alcohol abuse, and smoking are all examples of secondary infertility in women and men.
Sometimes problems getting pregnant for a second or subsequent time are related to a complication that occurred in a prior pregnancy or prior to delivery (damage to the uterus, for instance). But most often, secondary infertility is caused by the same factors that would cause primary infertility — issues like advanced age, obesity, ovulation problems and so on.