Congenital brain malformations

What are congenital brain malformations?

Congenital brain malformations are brain defects or disorders that develop in utero and are present at birth. They are thought to result from genetic and environmental factors. Early detection and treatment of congenital brain malformations may help reduce their impact on your child's brain development.

The fetal brain begins to develop shortly after conception and continues to grow throughout pregnancy. Billions of neurons, or nerve cells, undergo a critical development process in which they form brain regions. If anything interrupts this process, particularly during the first 12 weeks of pregnancy, brain malformations can result. These defects may also occur if the skull doesn't form properly.

Causes of congenital brain malformations

While the cause isn't always clear, congenital brain malformations may result from inherited genetic defects or spontaneous mutations within the embryo's genes. Factors thought to contribute to congenital brain malformations are similar to those associated with a number of other birth defects. These include:

• Genetics. Mutations in specific genes or abnormalities in chromosomes.
• Harmful substances. Exposure to certain medicines, alcohol or other drugs during pregnancy.
• Infections. Infectious diseases during pregnancy, such as rubella or contracting Zika virus.
• Radiation. Exposure to high levels of radiation during pregnancy.
• Maternal health issues. Examples are uncontrolled diabetes and poor nutrition, especially a lack of folic acid.
• Lack of oxygen. Insufficient oxygen to the fetal brain during pregnancy.
• Physical disruptions to brain development. This can result from certain conditions, such as amniotic band syndrome.

Symptoms of congenital brain malformations

Symptoms depend on the type and severity of the malformation. The prognosis – or likely outcome – also depends on these things. Some brain malformations are diagnosed at birth, while others may go undetected until adolescence or even adulthood.

Diagnosis of congenital brain malformations

Screening of biological parents during the pregnancy planning stages can help identify risks that may contribute to congenital brain malformations. Screening can also be done during pregnancy using ultrasound, blood tests and other methods. Finally, early screening of newborns is crucial for prompt detection of congenital brain malformations and other birth defects. Tools used to detect congenital brain malformations may include:

• Ultrasound. This imaging test uses sound waves to create images of the fetus. It can reveal malformations in the developing brain.
• Fetal magnetic resonance imaging (MRI). Producing detailed pictures of the fetus in utero, this test may be used if more information is needed after an ultrasound.
• Amniocentesis. For this test, the doctor takes a sample of fluid from the sac around the fetus to be analyzed for genetic problems.
• Whole genome sequencing. While some genetic tests check for just a few conditions, this technique looks at all the genes of the fetus or newborn, allowing for the detection of uncommon disorders.

Treatment of congenital brain malformations

Babies born with congenital brain malformations receive care from a team of specialists in our neuro-intensive care nursery (NICN), part of the UCSF William H. Tooley Intensive Care Nursery. The NICN provides high-level monitoring and treatment for babies at risk of neurological damage. We are also at the forefront of research studying brain malformations in newborns, particularly premature babies.