Skip to Main Content


A seizure is caused by sudden, abnormal and excessive electrical activity in the brain. By definition, neonatal seizures occur during the neonatal period – for a full-term infant, the first 28 days of life. Most occur in the first one to two days to the first week of a baby's life. Premature or low birth weight babies are more likely to suffer neonatal seizures.

Many of the visible signs of neonatal seizures – such as chewing motions and "bicycling" movements – also occur in healthy newborns. Therefore, testing is usually required to confirm the diagnosis.

The outcomes for babies who have neonatal seizures depend on the type of seizure and the underlying cause. Some neonatal seizures are mild and short-lived and therefore do not cause any lasting health problems. However, prolonged and untreated seizures can cause permanent damage due to decreased oxygen flow to the brain and excessive brain cell activity. Neonatal seizures are often symptoms of a more serious underlying condition, particularly brain injury. For this reason, babies experiencing neonatal seizures should receive rapid, specialized care.

About half of all babies who have neonatal seizures will develop epilepsy later in life. Those with seizures related to brain injuries or developmental abnormalities may have further complications, such as cerebral palsy, intellectual disability and other neurological disorders. These conditions result from the underlying brain damage, not the seizure itself.


Neonatal seizures have a variety of causes. These include:

  • Lack of oxygen before or during birth due to placental abruption (premature detachment of the placenta from the uterus), a difficult or prolonged labor, or compression of the umbilical cord
  • Infection acquired before or after birth, such as bacterial meningitis, viral encephalitis, toxoplasmosis, syphilis or rubella
  • Stroke before or after birth
  • Blood clot in the brain
  • Bleeding in the brain
  • Brain birth defects
  • Blood sugar or electrolyte imbalances
  • Metabolic disorders such as maple syrup urine disease, pyridoxine dependency or phenylketonuria (PKU)
  • Drug withdrawal, which may affect babies born to mothers addicted to barbiturates, alcohol, heroin, cocaine or methadone

In rare cases, neonatal seizures are caused by a condition called benign familial neonatal seizures, also known as fifth-day convulsions or fifth-day fits. This condition is inherited, and the baby's mother or father will also have had the disorder. Many babies with benign familial neonatal seizures develop normally, although some may have developmental delays that are seen in early childhood.

Signs & symptoms

Neonatal seizures can be difficult to diagnose because the seizure may be short and subtle. In addition, symptoms of neonatal seizures may mimic normal movements and behaviors seen in healthy babies.

Symptoms depend on the type of seizure — subtle, clonic, tonic or myoclonic.

Symptoms of Subtle Seizures

Subtle seizures are more common among full-term babies. Symptoms of subtle seizures include:

  • Random or roving eye movements, eyelid blinking or fluttering, eyes rolling up, eye opening, staring
  • Sucking, smacking, chewing and protruding tongue
  • Unusual bicycling or pedalling movements of the legs
  • Thrashing or struggling movements
  • Long pauses in breathing (apnea)

Symptoms of Clonic Seizures

  • Rhythmic jerking movements that may involve the muscles of the face, tongue, arms, legs or other regions of the body

Symptoms of Tonic Seizures

  • Stiffening or tightening of the muscles
  • Turning the head or eyes to one side, or bending or stretching one or more arms or legs

Symptoms of Myoclonic Seizures

  • Quick, single jerking motions, involving one arm or leg or the whole body


A test called an electroencephalogram (EEG) is essential for diagnosing and managing neonatal seizures. EEG records the electrical activity of the brain, and abnormalities on an EEG test (measured between seizures) can indicate a risk for seizures. However, babies with benign familial neonatal seizures usually have normal EEG readings.

Imaging tests of the brain, including magnetic resonance imaging (MRI) and computed tomography (CT) scan, are also used to determine the cause of seizures.


Prompt diagnosis and treatment of neonatal seizures is essential. Your baby's health care team will also work to identify and treat any underlying cause of the seizures.

To control the seizures, anticonvulsant medications may be prescribed, including phenobarbital, lorazepam and phenytoin. Your baby will be closely monitored at all times while receiving these medications.

Babies suffering from hypoxic ischemic encephalopathy (not enough oxygen to the brain) may receive hypothermia treatment, which may reduce brain damage caused by the lack of oxygen. Hypothermic treatment involves cooling the baby's brain and body by a few degrees immediately after birth for several hours or days. Babies are closely monitored during treatment, and then slowly re-warmed to normal body temperature.

UCSF Benioff Children's Hospitals medical specialists have reviewed this information. It is for educational purposes only and is not intended to replace the advice of your child's doctor or other health care provider. We encourage you to discuss any questions or concerns you may have with your child's provider.

Where to get care (1)

neurological-neonatal-intensive-care-unit-320x320-2x 2

Neuro-Intensive Care Nursery (NICN)

Neuro-Intensive Care Nursery (NICN)

San Francisco / Oakland

Recommended reading


Intensive Care Nursery Glossary

Our glossary explains the terms we use in the intensive care nursery in language that's easy to understand. Learn about chest tubes, respirators and more.


Intensive Care Nursery Parents' Guide

Is your baby in the intensive care nursery? Our guide helps you take an active role in your child's care, know what to expect and access support services.

Support services

Family Amenities

Family-friendly amenities help you relax and take care of yourself while staying close to your child. We offer lounges, kitchens, showers, breastfeeding rooms and more.

Family Resource Center

We help families cope with the challenges of childhood illness and hospitalization in a relaxing environment where parents can get a much-needed break.


Glogau Teddy Bear Rescue Fund

Families that need additional assistance during their child's hospital stay have access to toys, hotel vouchers and other amenities. Find out more.


Interpreter Services & Communication Assistance

Interpreter services in many languages and TDDs are available for families that need help communicating with care teams. Here's how to access them.


Patient Relations

Patient relations reps and nursing supervisors are here to answer questions and address concerns. Learn about your rights, how to reach us and more.


Social Services

Social workers ease the effect of illness, injury and hospitalization on your family with counseling and assistance to help you navigate the challenges.


Spiritual Care

Chaplains help UCSF patients, families and staff cope with the spiritual and emotional challenges of childhood illness. Learn more.

Clinical trials

See all clinical trials
1 in progress, 1 open to new patients
Decorative Caduceus

Neonatal Seizure Registry, GEnetics of Post-Neonatal Epilepsy

The presence or absence of a post-neonatal epilepsy diagnosis at age 5 in children with a prior history of acute symptomatic neonatal seizures will be determined by telephone interview with the parent and corroborated by medical r...


More about this study
Decorative Caduceus

Neonatal Seizure Registry - Developmental Functional EValuation

The WPPSI-IV is an in-person assessment administered by a psychologist or psychometrician that will be used to measure neurocognitive ability. Full Scale IQ (FSIQ) will be generated for each participant from the following subtests...


More about this study
See all clinical trials

Our research initiatives

  • ucsf-newborn-brain-research-institute-2x

    UCSF Newborn Brain Research Institute

    The Newborn Brain Research Institute promotes brain development and recovery by leveraging clinical excellence, a cutting-edge data hub and innovative basic and clinical research.

Special programs

Fetal Neurology Center of Excellence

Our specialists, leaders in the new field of fetal neurology, can provide prenatal diagnoses of birth defects that may affect the baby's nervous system.

Awards & recognition

  • One of the nation's best in neurology & neurosurgery

  • Ranked among the nation's best in 10 specialties

Staff superheroes

It’s a bird. It’s a plane. It’s a window washer! Dressed as a superhero to clean and brighten your day.