Incidence of Facial Nerve Palsy in Pregnancy

The facial nerve is cranial nerve number seven. A facial nerve palsy is a form of severe weakness of muscles of the face or paralysis due to swelling or any other kind of injury to the seventh nerve. Bell's palsy is the most common reason for facial nerve palsy in both pregnant and non-pregnant women, as well as in men and children. Palsy of the facial nerve is increased in conditions like pregnancy, diabetes, myasthenia gravis, Lyme disease, and multiple sclerosis, among others. The frequency of Bell's palsy in pregnant women is about three times that of an average person. There are several theories that have not been proven as to why this is the case. They are elevation of clotting factors in the blood, total body water causing compression and swelling of the facial nerve, increased level of female hormones like estrogen and progesterone, and the weakening of immune system in the third trimester of pregnancy, leading to reactivation of many viruses. Also, Bell's palsy during pregnancy has been linked to pre-eclampsia, which is also referred to as pregnancy-induced high blood pressure. Other associated factors are hemolysis, low platelets, which is a variant of pre-eclampsia, and elevated liver enzymes. Women are also susceptible to paralysis after childbirth. Most of the women who develop Bell's palsy after pregnancy start showing signs and symptoms seven to 10 days after the date of delivery.