Hydranencephaly is a rare condition in which the front hemispheres of the brain, known as the cerebrum, are absent. Instead that space is filled with cerebrospinal fluid.

Hydranencephaly is a defect of the central nervous system (CNS). It occurs in the earliest stages of fetal development. The condition causes both neurological and physical impairment.

It is sometimes referred to as a cephalic disorder, birth defects of the head caused by problems in the development of the fetal nervous system.


Pregnancies involving hydranencephaly are at increased risk of miscarriage and stillbirth.

Babies born with hydranencephaly often don’t survive more than a few weeks or at most, a year. Those who do have reduced life expectancies.

How does hydranencephaly affect my baby?

Common complications found in children with hydranencephaly include:

  • An enlarged head
  • Intellectual disability
  • Blindness or vision problems
  • Seizures and uncontrolled movements (twitching and spasms)
  • Excess fluid in the brain (hydrocephalus)
  • Lack of growth (failure to thrive)
  • Increased muscle tone
  • Deafness
  • Chronic respiratory problems
  • Gastrointestinal complications
  • Inability to maintain body temperature

Cause and Risk Factors

Hydranencephaly is believed to result from an interruption of blood supply to the fetal brain, affecting the normal development of the central nervous system.

While the exact cause is unknown, suspected risk factors include:

  • Intrauterine infection
  • Blockage in the carotid artery, the blood vessel that carries blood to the brain
  • Twin-twin transfusion syndrome (TTTS), a condition in which identical twins share one placenta and one twin receives too much blood and the other too little
  • Other circulation problems
  • Exposure to environmental toxins
  • Genetics  

The condition occurs in an estimated 1 in every 250,000 newborns in the United States.

Diagnosis During Pregnancy

In some cases, hydranencephaly is detected during a routine prenatal ultrasound. An MRI of the fetal brain may be performed to confirm the diagnosis.

If your baby is diagnosed during pregnancy, you may be referred to a fetal center for a comprehensive evaluation and specialized care. At Texas Children’s Fetal Center, we arrange for a detailed assessment by a team of specialists experienced in the diagnosis and care of rare fetal brain defects, including maternal-fetal medicine (MFM) physicians, fetal imaging experts, genetic counselors, neonatologists, and pediatric neurologists and neurosurgeons.

Additional testing may include:

Following this thorough evaluation, our specialists will meet with you about your results, answer any questions you have, and discuss your baby’s prognosis and possible treatment needs at birth.

Treatment During Pregnancy

If hydranencephaly is diagnosed during pregnancy, you and your baby will be closely monitored to watch for signs of complications, including miscarriage. We recommend delivery at a hospital with the expertise and resources required to care for newborns with these rare brain defects, including the highest level neonatal intensive care unit (NICU).

Our Fetal Center team works closely with pediatric experts from Texas Children’s Hospital, including neurologists and neurosurgeons experienced in the care of children with rare defects of the central nervous system, ensuring the best possible care for your baby every step of the way. Texas Children’s is consistently ranked one of the best children’s hospitals in the nation by U.S. News & World Report.

Diagnosis After Birth

In many cases, hydranencephaly isn’t diagnosed until after the baby is born. The condition may be evident at birth, based on obvious symptoms such as an enlarged head. Or the newborn may appear healthy and developmentally normal and the diagnosis isn’t made until weeks or months later when symptoms appear.

Common signs and symptoms include:

  • Increasing head size
  • Failure to grow at a normal rate
  • Difficulty feeding
  • Irritability
  • Twitching, spasms or seizures
  • Rigid or stiff arms and legs
  • Increased muscle tone
  • Vision problems
  • Breathing difficulties
  • Deafness
  • Developmental delays
  • Difficulty regulating body temperature


There is no treatment to restore the loss of brain tissue. Treatment is focused on managing the baby’s symptoms.

Babies who develop hydrocephalus, or excess fluid in the brain, will require a shunt (hollow tube) surgically implanted in the brain for life to drain the excess fluid and relieve pressure inside the child’s head.

Additional treatments and long-term care will be based on the needs of each child.

Postnatal Care Team

A unique and distinct advantage for mothers delivering at Texas Children’s Pavilion for Women is our location inside one of the largest and most renowned children’s hospitals in the world, for seamless access to the critical care services and specialists your child may need.

For babies with hydranencephaly, this means no transfers during critical postnatal periods. It also means that the pediatric specialists responsible for treating your child have been an integral part of their care team since before birth.

Depending on your baby’s symptoms, his or her postnatal care team may include:

Patient Support Services

Education, advocacy and emotional support are vital to helping families navigate the challenges of a diagnosis of hydranencephaly.

Our Fetal Center patients benefit from:

Why Texas Children’s Fetal Center?

  • A single location for expert maternal, fetal and pediatric care. At Texas Children’s Hospital, you and your baby receive the specialized care required for the diagnosis and care of hydranencephaly all in one location, including immediate access to our level IV NICU, the highest level of care available for premature and critically ill newborns.
  • An experienced, compassionate team of specialists. We have a dedicated team of maternal-fetal medicine specialists, neonatologists, fetal imaging experts, pediatric neurosurgeons, and others who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this remarkable team offers the best possible care for pregnancies and babies with hydranencephaly.
  • We care for your child’s needs at every stage of life. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, and beyond, thanks to one of the nation’s leading teams of fetal and pediatrics specialists for the care and treatment of rare fetal brain defects.

For more information or to schedule an appointment,

call Texas Children’s Fetal Center at 832-822-2229 or 1-877-FetalRx (338-2579) toll-free.

Our phones are answered 24/7. Immediate appointments are often available.