Definition

Facial nerve palsy due to birth trauma is the loss of controllable (voluntary) muscle movement in an infant's face due to pressure on the facial nerve just before or at the time of birth.

Alternative Names

Seventh cranial nerve palsy due to birth trauma; Facial palsy - birth trauma; Facial palsy - neonate; Facial palsy - infant

Causes

A person's facial nerve is also called the seventh cranial nerve. In infants, it can be damaged just before or at the time of delivery.

Most of the time, the cause is unknown. But a difficult delivery, with or without the use of an instrument called forceps, may lead to this condition.

Some factors that can increase the risk of birth trauma (injury) include:

• Large baby size (may be seen if the mother has diabetes)
• Long pregnancy or labor

Most of the time, these factors do not lead to facial nerve palsy or birth trauma.

Use of epidural anesthesia and medicines to induce labor and contractions indicate more difficult deliveries, which are at greater risk of complications such as nerve injury.

Symptoms

The most common form of facial nerve palsy due to birth trauma involves only the lower part of the facial nerve. This part controls the muscles around the lips. The muscle weakness is mainly noticeable when the infant cries.

The newborn infant may have the following symptoms:

• Eyelid may not close on affected side
• Lower face (below eyes) appears uneven during crying
• Mouth does not move down the same way on both sides while crying
• No movement (paralysis) on the affected side of the face (from the forehead to the chin in severe cases)

In some cases, other cranial nerves may be affected as well.

Exams and Tests

A physical exam is usually all that is needed to diagnose this condition. In rare cases, a nerve conduction test is needed. This test can pinpoint the exact location of the nerve injury.

Brain imaging tests are not needed unless your infant's health care provider thinks there is another problem (such as a congenital brain injury or infection).

Treatment

In most cases, the infant will be closely monitored to see if the paralysis goes away on its own.

If the baby's eye does not close all the way, an eyepad and eyedrops will be used to protect the eye.

Surgery may be needed to relieve pressure on the nerve.

Infants with permanent paralysis need special therapy.

Outlook (Prognosis)

The condition usually goes away on its own in a few months.

Possible Complications

In some cases, the muscles on the affected side of the face become permanently paralyzed.

When to Contact a Medical Professional

Your provider will usually diagnose this condition while the infant is in the hospital. Mild cases involving just the lower lip may not be noticed at birth. A parent, grandparent, or other person may notice the problem later.

If the movement of your infant's mouth looks different on each side when they cry, you should make an appointment with your child's provider.

Prevention

There is no guaranteed way to prevent pressure injuries in the unborn child. The proper use of forceps and improved childbirth methods have reduced the rate of facial nerve palsy.

References

Balest AL, Riley MM, O' Donnell B, Zarit JS. Neonatology. In: Zitelli BJ, McIntire SC, Nowalk AJ, Garrison J, eds. Zitelli and Davis' Atlas of Pediatric Physical Diagnosis. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 2.

Harbert MJ, Pardo AC. Neonatal nervous system trauma. In: Swaiman KF, Ashwal S, Ferriero DM, et al, eds. Swaiman's Pediatric Neurology. 6th ed. Philadelphia, PA: Elsevier; 2017:chap 21.

Sears CM, Erickson BP, Kossler AL. Lids: congenital and acquired abnormalities - practical management. In: Lyons CJ, Lambert SR, eds. Taylor & Hoyt's Pediatric Ophthalmology and Strabismus. 6th ed. Philadelphia, PA: Elsevier; 2023:chap 17.