A 32-year-old woman attends the antenatal clinic at 14 weeks of gestation (by LMP). Transvaginal ultrasound performed at 8 weeks had confirmed a single intrauterine pregnancy with normal cardiac activity. Today, repeat transabdominal ultrasound shows a crown-rump length (CRL) of 72 mm, which corresponds to 12 weeks of gestation. She is asymptomatic with no vaginal bleeding. What is the most appropriate next step in management?