en General General Original Research Original Research The purpose of this prospective study was to determine the effect of calcium supplementation in the incidence of hypertensive disorders of pregnancy (gestational hypertension and pre-eclampsia) in nulliparous and high risk women. 300 pregnant women in the 24th week of gestation at the beginning of the study were entered into a double-blind randomized trial. 143 of them who had a positive roll-over test and hypocalciuria at the 28-32nd week of gestation were enrolled for the study. Subjects were assigned to receive 2 g per day of elemental calcium (52 women) or placebo (61 women) from the 28-32nd week of pregnancy until delivery. Results showed that 11.4% of calcium-treated subjects developed gestational hypertension, compared to 31.2% of the placebo group. The rate of hypertensive disorders of pregnancy was also higher in the placebo group (35.6% vs 11.4%, p<0.01). 11 14 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-489&slc_lang=en&sid=1 ESMAT BABADIZAVANDY 20031947532846004893 20031947532846004893 Yes From the Department of Nursery and Midwifery, Mashhad University, Mashhad, Islamic Republic of Iran. GHODSIH SEYYEDI ALAVI 20031947532846004894 20031947532846004894 No MASOMEH CORDI 20031947532846004895 20031947532846004895 No