Prevention of pregnancy-induced hypertension by calcium supplementation in angiotensin II-sensitive patients.
OBJECTIVE
To evaluate the efficacy of oral supplemental calcium in reducing the incidence of pregnancy-induced hypertension (gestational hypertension or preeclampsia) in angiotensin-sensitive nulliparas.


METHODS
Sensitivity to intravenously infused angiotensin was determined at 24-28 weeks' gestation in 281 nulliparous women who had positive roll-over tests. Angiotensin-sensitive women were given 2 g/day of oral elemental calcium or placebo in a randomized, double-blind clinical trial. The tablets were dispensed by the hospital pharmacy in serially numbered computerized pill bottles so as to assess compliance. Repeat angiotensin sensitivity test was performed at 34-36 weeks' gestation.


RESULTS
Sixty-three of 67 angiotensin-sensitive nulliparas were evaluable; 29 received calcium and 34 received placebo tablets. Four of 29 calcium-treated subjects (13.8%, 95% confidence interval [CI] 4-32%) developed preeclampsia, compared to 15 of 34 (44.1%, 95% CI 27-62%) in the placebo group (relative risk [RR] 0.37, 95% CI 0.15-0.92; P = .01). The incidence of any type of hypertension was nine of 29 (31%, 95% CI 15-51%) with calcium treatment, compared to 22 of 34 (64.7%, 95% CI 46-80%) with placebo (RR 0.46, 95% CI 0.25-0.86; P = .01).


CONCLUSIONS
Calcium supplementation given in pregnancy to high-risk nulliparas reduces the incidence of pregnancy-induced hypertension.
Sanchez-Ramos
L
L
Department of Obstetrics and Gynecology, University of Florida Health Science Center, Jacksonville.
Briones
D K
DK
Kaunitz
A M
AM
Delvalle
G O
GO
Gaudier
F L
FL
Walker
C D
CD
D000293:Adolescent; D000328:Adult; D000804:Angiotensin II; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000008:administration & dosage / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000517:prevention & control*; D015994:Incidence; D010298:Parity; D011225:Pre-Eclampsia / Q000453:epidemiology / Q000517:prevention & control*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular / Q000453:epidemiology / Q000517:prevention & control*; D012307:Risk Factors
D000804:Angiotensin II; D002118:Calcium