Not necessary. A paracervical block is an injection of local anesthetic (numbing medicine) around your cervix. Some doctors may choose to use a paracervical block while removing an iud. Others believe the injection itself is just as painful than taking the iud out. Typically, no anesthesia is needed for removing an iud.
Numbing. Anesthesia is numbing...Either general anesthesia (completely going to sleep) or local (numbing a nerve or an area). A paracervical block is a local injection to numb up the cervix. However, these are rarely needed for an iud removal, as this can generally be done without anesthesia - quickly and mostly painlessly.
Decreased Pain. Essentially anesthesia is decreased sensitivity to pain. This can be performed by either local anesthesia at the site of operation, regional anesthesia to numb an entire area of the body, or general anesthesia where the entire body is put to sleep. For the removal of an iud your ob/gyn doctor can perform a para-cervical block to decrease your pain. You might be offered some sedation as well.