My daughter was born with hypoplastic left heart syndrome and not diagnosed by ultrasound. why not?

Screening ultrasound: Most probably, you had routine screening ultrasounds by your obstetrician during your pregnancy. Severe forms of hypoplastic left heart syndrome (hlhs) may be picked up by experienced obstetricians during their routine studies, but less severe forms may not. If the obstetrician suspects heart disease, he/she will refer you to a pediatric cardiologist for a complete fetal echocardiogram prenatally.