RESEARCH QUESTION In women with pregnancy hypertension (P), what is the effect of treatment with nifedipine (I) versus labetalol (C) on severe maternal hypertension (O) and a composite of fetal or neonatal death, or neonatal unit admissions (O)? AIM To evaluate the effect of different antihypertensive drugs in pregnancy hypertension on maternal and fetal/neonatal outcomes. PRIMARY OBJECTIVE Primary objective: To evaluate if treatment with nifedipine (calcium channel blocker), compared to labetalol (mixed alpha/beta blocker) in women with pregnancy hypertension, reduces severe maternal hypertension without increasing fetal or neonatal death, or neonatal unit admission.