A 30-year-old G1P0 at 32 weeks' gestation presents with new-onset hypertension (BP 152/96 mm Hg) and 2+ protein on urine dipstick, with mild headaches but no visual changes or right upper quadrant pain. Platelets, creatinine and liver enzymes are normal, and there is no severe hypertension. According to SOGC guidance, what is the most appropriate diagnosis?