Twins but one no heartbeat.. is there a chance?

Hi all,

I’m 7+4 with my first pregnancy and so excited!

At our 6 weeks scan the doctor saw one baby who looked good with a heartbeat.

She also saw another gestational sac but couldn’t get a good image and no heartbeat. She estimated that the baby has about 30% chance of survival.

My question is has anyone else experienced this and had the baby end up surviving?

Thanks in advance!