20 weeks Anatomy scan

Are you asking about ARSA? One of my twin is diagnosed with ARSA and my previous gynae asked us to do amniocentesis when all other organs are normal. I was hesitant as there's a risk of miscarriage so I spoke to a high risk specialist and he calculated that our risk of baby having issue will be 2-4% so we decided not to do the amniocentesis and just believe that baby will be fine. The high risk specialist did mention that there's a lot of ARSA cases in which baby turned out to be completely fine.