The Fetal Medicine Foundation has funded and coordinated several major multicentre randomized trials to investigate the potential value of interventions in the prevention of preeclampsia, preterm birth and macrosomia. The studies demonstrated that:

• Aspirin (150 mg/day) started from 12 weeks of gestation can substantially reduce the risk of preterm preeclampsia
• Aspirin (150 mg/day) started from 23 weeks of gestation does not reduce the risk of preeclampsia
• Pravastatin (20 mg/day) started from 36 weeks of gestation does not reduce the risk of term preeclampsia
• Progesterone (200 mg/day) in women with short cervix can substantially reduce the risk of preterm birth
• Progesterone (600 mg/day) in women with twin pregnancies does not reduce the risk of preterm birth
• Cervical cerclage in women with short cervix does not reduce the risk of preterm birth
• Cervical pessary in women with short cervix does not reduce the risk of preterm birth
• Metformin in obese women does not reduce the risk of macrosomia but it reduces the risk of preeclamsia.