Hi,
So sorry for your losses, I don't know much about Trisomy 15 but two years ago my baby was stillborn and he had Trisomy 13. We have gone on to have a healthy baby girl last year. Have you seen a genetic counsellor? We were told the chances of having another Trisomy 13 baby was 1/10,000 but as I said not sure about Trisomy 15.
I wish you lots of luck and all the best.

Regards,
Dianne