HI Lisa,
FIrstly *hugs* There are no words to make everything better.
After the initial diagnosis by the sonographers, I was sent for a tertiary scan where everything was said to be ok. Nothing was said again after 28 weeks.
DS' ventricles were classed as on the upper end of normal, and yes, I freaked out too. Nothing was going to make me feel better except giving birth and seeing how he was. I was truly scared to start with, but after the initial shock, I felt that everything was ok. Mother's intuition if you will.
It's good that none of your other ultrasounds have picked up anything else. Were you told at your morphology scan (19 weeks) of the enlarged brain ventricles? Or have they only just detected this?
Try and remember and think, your baby is till in the normal range.
DS underwent a cranial ultrasound a week after he was born, and although his ventrivcles were still larger than average, there was nothing at all wrong. I was informed that if every baby was to be scanned after birth, 2 in every 10 would have the same thing. That really made me feel easier. To date, he is one healthy happy 9 month old, with no problems whatsoever. His head is not ridiculously large at all, so no problems.
Good luck with your MRI scan. I really hope that everything is still in the normal range for you.
Everyone I have ever spoken to on parenting and pregnancy websites, has had an excellent outcome.
Good luck.