Which is best method to assess fetal damage in a diabetes mother in 1st trimester is:
Blood sugar estimation
Urine ketone assay
Amniocentesis to see level of sugar in amniotic fluid
Glycosylated Hb
In diabetic patients:

Most sensitive test/best test to assess the risk of fetal malformation is maternal HbA1 c levels
The best test to detect fetal malformations is USG.

Now question says - which is the most sensitive screening test to detect congenital malformations. Undoubtedly ultrasound should be the first choice but it is not given in the options.