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Fetal pregnancy complications


Types of Abdominal Wall Defects : Explaining Gastroschisis and Omphalocele

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The ventricles of the brain are “pockets” containing cerebrospinal fluid that nourishes the brain and spinal cord.

Ventriculomegaly is diagnosed if the cerebral ventricles measure greater than 10 mm.

This condition is seen in 0.3 to 10 cases per 10,000 newborns and is classified based on the size of the ventricles:

  • Minor ventriculomegaly = between 10.1 mm and 12 mm
  • Moderate ventriculomegaly = between 12.1 mm and 15 mm
  • Severe ventriculomegaly = over 15 mm


Ventriculomegaly can simply be a normal variation; some babies have ventricles that are a little larger than average. This will not pose any problems later in life, which is most often the case with mild ventriculomegaly.

Ventriculomegaly can be a sign of chromosomal abnormality, such as trisomy 21. To properly quantify this risk, it is important to check whether the risk of trisomy 21 has already been screened for and assessed and if there are any other ultrasound abnormalities.

Ventriculomegaly can also be a sign of infection or bleeding in a baby’s ventricle.

Ultimately, ventriculomegaly can be the first sign of abnormal development of the baby’s brain.

Tests and procedures

A detailed ultrasound of the baby’s morphology is needed to see if the ventriculomegaly is isolated or if it is associated with other abnormalities. An ultrasound can help determine the cause of the ventriculomegaly.

A fetal brain magnetic resonance (also called fetal MRI) may be considered in certain situations to better define the anatomy of the baby’s brain. The MRI poses no risks to either the baby or the mother.

To look for certain causes of the condition, blood tests of expectant mothers may be ordered, like the TORCH panel test that is used to help diagnose infections. Blood tests can also detect if the mother’s and baby’s platelets have become incompatible (known as platelet alloimmunization), which could cause bleeding.

In some cases, having an amniocentesis may be discussed.

Treatments and follow up

Ultrasound follow-up will be offered to monitor changes in the size of the ventricles.

In the event of platelet alloimmunization or infection, treatment may be started.

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Dre Marie-Ange DelrueDre Aspasia Karalis Dre Anne LortieDre Lucie Morin
Dre Fran├žoise Rypens

About this page
Updated on 1/25/2021
Created on 1/25/2021
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