You need to consult a paediatric surgeon along with an obstetrician, and plan your delivery at a centre equipped to handle paediatric cardiac cases. First the diagnosis will need to be confirmed by a fetal echo- while baby is in utero. The VSD if present- will need to have follow-up scans for size and any cardiac failure. Also, other foetal defects may need to be ruled out. Is it only a single defect or there are others associated, making it part of a syndrome, in which case chance of fetal survival needs to be evaluated. Please have a full check-up with echo and then treatment options can be planned as a team, if foetal survival after delivery can be achieved.