The mucus or fluid produced by the cervix can either help or hinder the movement of the sperm into the cervix through the womb into the fallopian tube. If there is not enough mucus or if it is too thick and sticky or the mucus does not match with the husband's sperm, it can cause infertility. A cervical mucus test is done to assess whether the mucus is normal or not.
Attribution: Straight Talk Foundation