MSFinals-3659

A 20-year-old primigravida presents to your clinic with a complaint of persistent vomiting. She is currently 12 weeks pregnant and has been experiencing this symptom for the past four days. Upon examination, you note that she has a fast heart rate, low blood pressure upon standing, and her urine test shows the presence of ketones. What is the most significant risk factor for hyperemesis gravidarum?