Hi again Nicky - well Sophie has finally arrived, happily healthily at full term!
Paediatrician checked her over and said all is fine and no problems re the ventriculomegaly diagnosis at 20 weeks. He mentioned that ultrasounds are perhaps detecting too much these days and that a slight variation from normal measurement can cause parents to worry for nothing.
Sophie does have a soft heart murmur though but this is apparently nothing to spare a second thought about and may well have resolved itself by the time we see the paed in December.