1. Unilateral borderline ventriculomegaly may be genetically inherited condition
Selim Buyukkurt, Mete Sucu, Mehmet Ozsurmeli, Cihan Cetin, Erol Arslan, Selahattin Misirlioglu, Suleyman Cansun Demir, Ismail Cuneyt Evruke

2. Ventriculomegaly
Most frequent malformation of fetal brain (0,3-1,5/1000 live births)
Dilatation of the atrium of lateral ventricle of brain.
Diameter at the level of atrium is more than 10 mm.

3. Where is the atrium?

4. How to measure proximal ventricle?

5. How to measure atrium?
Parito-occipital sulcus
UOG 2009; 34:

6. Normal ranges and limits
Normal: 3-10 mm
Borderline ventriculomegaly: mm
Mild ventriculomegaly: mm
Severe ventriculomegaly: > 15 mm
Asymmetry: δ>2 mm
Asymmetric ventriculomegaly: Asymmetry + ventriculomegaly
Unilateral borderline ventriculomegaly

7. Case
A 35-year-old gravid 4, para 3 patient was referred for routine mid-trimester scan.
She had spontaneous monochorionic twin pregnancy. The gestational age was 21 weeks old and sonographic appearances of both fetuses were normal except unilateral borderline ventriculomegaly in right side of brain each.
Right ventricular width was measured 11,8 mm and 11,5 mm in each fetuses.

9. She refused the amniocentesis but agreed for TORCH serology and fetal cerebral MRI.
TORCH serology was negative
Fetal MRI was consistent with the sonographic findings.
During the regular follow-up, enlarged ventricles remains stable and any other additional abnormality was not detected.

10. She delivered at term and neonatal evaluation of fetuses were normal
She delivered at term and neonatal evaluation of fetuses were normal. Neonatal transfontanel cerebral sonography also confirmed the prenatal diagnosis.
Now both of children are at age of four and their neurological development and growing are appropriate with the age.

11. They concluded that isolated cases have a good neurological prognosis.
Previously Lipitz et al. have reported a short serie of fetuses with unilateral borderline ventriculomegaly (n=27).
They concluded that isolated cases have a good neurological prognosis.
UOG 1998;12:23–26

12. Negative prognostic factors
Any other additional malformation
Chromosomal abnormality
Progression of ventriculomegaly
Positive TORCH serology

13. İsolated ventriculomegaly
It is a diagnosis of exclusion.
Even in expert hands fetal MRI or TV USG can miss the diagnosis in 13%.
3D multiplanar examination may help to obtain better images.
The absolute advantage of fetal MRI is the evaluation cortex after weeks.

14. Here, we are presented a case of monochorionic twin pregnancy in which both of the fetuses had unilateral borderline ventriculomegaly.
Previously Muhler et al have reported that a male fetus with unilateral borderline ventriculomegaly and his mother had also same radiological finding.
UOG 2008; 31: 358–365

15. To best of our knowledge, this is the first case of unilateral borderline ventriculomegaly diagnosed in monochorionic twin pregnancy and second case suggesting the genetic inheritage.
Whether this is condition is genetically inherited or not, in the absence of progressive dilatation in ventricle size, additional sonographic abnormally, positive TORCH serology or abnormal fetal karyotype the expected prognosis is usually good.