Which class of medication is associated with low sperm count?

Selective Serotonin Reuptake Inhibitors (SSRIs) have been associated with a range of side effects, one of which includes potential effects on reproductive health, particularly in males. Research suggests that SSRIs can impact testosterone levels and may contribute to diminished sperm production, thereby leading to low sperm count. The mechanism is believed to involve the suppression of the hypothalamic-pituitary-gonadal axis, disrupting the hormonal balance necessary for normal sperm development.

Although other medication classes listed can have side effects, SSRIs have the most documented connection specifically to changes in male reproductive health concerning sperm count. Hence, the association of SSRIs with low sperm count makes it the correct choice in this context.