Risk of heart defect after 12 week NT ultrasound?

We had our 12 week detail ultrasound the other day and based on the thickness of the nuchal fold, they said baby may be at risk (2-6%) for a heart defect. They are having us come back at 16 weeks for a another scan when the baby’s heart is more developed. Has anyone else had this experience? We are trying to figure out what to expect. Our first pregnancy ended in a miscarriage, so we still haven’t told friends or family yet. Not sure how much longer we can keep it a secret, or if we should. Our panorama test came back low risk for all tested chromosomal issues, which also made the doctors think it was heart related. Any advice is appreciated!