Calcium Supplementation to Prevent Preeclampsia in Sichuan Province of China

Calcium Supplementation to Prevent Preeclampsia in Sichuan Province of China: a Multi-center, Prospective Random Trial

the purpose of this study is to determine whether calcium supplementation is effective to prevent preeclampsia in Sichuang Province of china and which dose is more suitable

Inclusion Criteria:

• Nulliparity;age ≥35 years;Previous pre-eclampsia;Family history of pre-eclampsia;Multiple pregnancy;Time between pregnancies ≥10years;Body mass index ≥25;diastolic pressure ≥ 80 mm Hg before 20 weeks' gestation;Proteinuria ≥+ on more than one occasion or ≥ 300 mg/24 h before 20 weeks' gestation;Underlying medical conditions(Pre-existing hypertension;Pre-existing renal disease;Pre-existing diabetes;Presence of antiphospholipid antibodies;Chronic autoimmune disease);male sex partner's predecessor wife has Previous pre-eclampsia

Exclusion Criteria:

• first prenatal visit after 16 weeks' gestation;severe anemia;other Underlying medical conditions which need treatment first (such as uncontrolled hyperthyreosis )