What are the most important complexities and/or complications-i.e., cord entanglement, singleton demise, or twin-to-twin transfusion syndrome-encountered in twin pregnancies?

What are the most important complexities and/or complications-i.e., cord entanglement, singleton demise, or twin-to-twin transfusion syndrome-encountered in twin pregnancies?

What are the most important complexities and/or complications-i.e., cord entanglement, singleton demise, or twin-to-twin transfusion syndrome-encountered in twin pregnancies; and why do they provide a rationale for early and systematic SNP-based NIPT evaluation to mitigate risk, initiate surveillance, and optimize management of these patients?