A 32-year-old G2P1 with chronic hypertension presents at 28 weeks gestation for routine antenatal review. Ultrasound shows estimated fetal weight 850 g (3rd centile), amniotic fluid volume normal, and umbilical artery Doppler with absent end-diastolic flow (AEDF). Middle cerebral artery (MCA) Doppler shows pulsatility index at 5th centile (low). Cerebroplacental ratio is 0.8 (abnormal). Fetal heart rate is 140 bpm with normal baseline variability. What is the most appropriate management?