A 24-year-old primigravida from Delhi presents for her first antenatal scan at 12 weeks of gestation (by last menstrual period). Transvaginal ultrasound shows a crown-rump length (CRL) of 48 mm. The sonographer notes increased nuchal translucency (NT) measuring 3.2 mm. There is no fetal bradycardia, and the nasal bone is visualized. What is the most appropriate next step in management?