It has always been assumed that it was the age of the mother which was a factor in the conception of Downs syndrome babies, but I understand that it is in fact the father's age that makes the difference. So it is down to Mike and not Vicky.
We have a second cousin with Down's syndrome, her mother was 40 something when she was born and her father in his late 50's/early 60's. In a way she has been lucky as she will always be provided for, but sadly her father died of a stroke about 5 years ago just a year after their son, her older brother, dropped dead playing rugby in his late 20's . We always thought that he would the person to look after her after his parents had gone, but sadly that was not to be.