Hypertensive disorders of pregnancy (HDP) are with 50.000 deaths every year one of the major causes of maternal mortality worldwide, especially in low and middle income countries. This trial aims to determine whether a daily dose of combined low-dose aspirin, calcium, vitamin D3, folic acid and vitamin B12 in pregnancy reduces the incidence of pregnancy-induced hypertension in women at risk. Secondary and tertiary objectives include other maternal and neonatal outcomes.