Vein of Galen

Is anyone familiar with this brain malformation? One of my twins may have it and I'm terrified, waiting for a MRI next week to confirm. He prob won't make it and they're telling me he will most likely die in utero. This is a rare disorder so I don't have answers to any questions such as how it will affect my other baby and myself if he should pass and I miscarry. I'm so heartbroken and scared. He's still actively kicking. Both are. I'm just about 22 weeks and had no abnormal readings up to now so this is all very sudden and surreal. Any insight would help. Mahalo 🌺