Time and again we have written in this column that it is impossible to comment on a stand-alone ultrasound report. I do not understand the term mild to moderate, either you have ventriculomegaly or you do not. The term mild ventriculomegaly generally means a atrial width of 10 to 15 mm (up to 10 mm is normal) and is associated with normal outcome in 4 out of 5 cases and abnormal babies are seen in 23 % of such cases. Hence it can be fairly benign and sometimes transient. However further tests are required to know whether the fetus would be normal or not like 4% risk of chromosomal abnormality (slightly more in twins) and intrauterine infections. And you need a consultation with a fetal medicine specialist before you proceed with your pregnancy.
Overt Ventriculomegaly (when the atrial width is more than 15 mm) however is associated with all kinds of abnormalities. Intrauterine (before birth) treatments have been tried but have not proven to be useful and shunts devised about 10-15 years ago have largely been given up now.
(I have never heard the term moderate ventriculomegaly and so am at a loss for words to comment on it, but it may mean somewhere in between of the failure of the ultrasound doctor to make a clear diagnosis)
Please ask your ultrasound doctor to make a commitment and a clear diagnosis with measurements of lateral ventricles including details of the rest of the fetal anatomy especially the head structures. Well if the fetus does have ventriculomegaly it is indeed a problem. You have to follow the advice of your treating physician. But it may be helpful to get a second opinion on the Ultrasound and a clear diagnosis.
If indeed you do have ventriculomegaly diagnosis of the cause is essential. The rest of the treatment will depend of the abnormality if any. If indeed one twin is considered abnormal selective reduction can be considered. It is a specialised procedure done by only a fetal medicine specialist. Means the affected (abnormal) twin can be removed before birth while the normal one is salvaged.
Well at this stage it is all too premature to discuss such horrible possibilities. So please get clear diagnoses before you decide what needs to be done and start to worry.
I wish you all the best. And please take a decision what to do after you have a clear diagnosis and detailed counselling.