A 30-year-old woman at 30+2 weeks has hypertension controlled with oral therapy and an ultrasound-estimated fetal weight below the third centile. Umbilical artery Doppler shows persistent absent end-diastolic flow, but the ductus venosus waveform and cardiotocograph are normal. She has no headache, visual symptoms or upper abdominal pain, and laboratory investigations are stable. Which one of the following is the most appropriate management?