Does marijuana have an effect on sperm and therefore fertility?

Yes. Mild effects on sperm count, motility, and morphology, and effects on sperm dna fragmentation have been identified with mj use. Interest in sex is diminished in some. Some change in diet and nutrition is common. These effects are dose related. When trying to conceive, you are setting a foundation for your child's future. Don't use drugs or alcohol if you are trying to conceive.