What things increase risk of infertility?

Age, STDs, smoking. Women's fertility starts to decrease from the mid 20's, fastest by the 40's. Smoking, stds like chlamydia, endometriosis, ovarian surgery, chemo- or radiotherapy reduce egg numbers & quality. Chlamydia, pid, endometriosis or surgery can block fallopian tubes. Overweight or underweight lowers fertility. For men - testosterone or anabolic steroid use, overweight, heavy alcohol or weed, narcotic use.