RESUMEN
BACKGROUND: Epidemiological findings suggest that the link between poverty and pre-eclampsia might be dietary calcium deficiency. Calcium supplementation has been associated with a modest reduction in pre-eclampsia, and also in blood pressure (BP). METHODS: This exploratory sub-study of the WHO Calcium and Pre-eclampsia (CAP) trial aims to determine the effect of 500mg/day elemental calcium on the blood pressure of non-pregnant women with previous pre-eclampsia. Non-pregnant women with at least one subsequent follow-up trial visit at approximately 12 or 24weeks after randomization were included. RESULTS: Of 836 women randomized by 9 September 2014, 1st visit data were available in 367 women of whom 217 had previously had severe pre-eclampsia, 2nd visit data were available in 201 women. There was an overall trend to reduced BP in the calcium supplementation group (1-2.5mmHg) although differences were small and not statistically significant. In the subgroup with previous severe pre-eclampsia, the mean diastolic BP change in the calcium group (-2.6mmHg) was statistically larger than in the placebo group (+0.8mmHg), (mean difference -3.4, 95% CI -0.4 to -6.4; p=0.025). The effect of calcium on diastolic BP at 12weeks was greater than in those with non-severe pre-eclampsia (p=0.020, ANOVA analysis). CONCLUSIONS: There is an overall trend to reduced BP but only statistically significant in the diastolic BP of women with previous severe pre-eclampsia. This is consistent with our hypothesis that this group is more sensitive to calcium supplementation, however results need to be interpreted with caution.
Asunto(s)
Determinación de la Presión Sanguínea , Presión Sanguínea/efectos de los fármacos , Conservadores de la Densidad Ósea/administración & dosificación , Calcio de la Dieta/administración & dosificación , Preeclampsia/prevención & control , Complicaciones Cardiovasculares del Embarazo/prevención & control , Adulto , Argentina , Determinación de la Presión Sanguínea/métodos , Método Doble Ciego , Femenino , Humanos , Embarazo , Medición de Riesgo , Sudáfrica , Resultado del Tratamiento , Organización Mundial de la Salud , ZimbabweRESUMEN
OBJECTIVE: The purpose of this study was to determine the predictive value of elevated mean arterial pressure in the second half of pregnancy for both preeclampsia and gestational hypertension. STUDY DESIGN: This was a cohort of 588 nulliparous pregnant women studied prospectively from the twentieth week until delivery. Mean arterial pressure was obtained by means of a random-zero sphygmomanometer at 20, 26, and 31 weeks of gestation. The best cutoff point for the determination of predictive values was established by a receiver-operator characteristic curve. RESULTS: Patterns of mean arterial pressure throughout pregnancy were different between preeclamptic and gestational hypertensive women. Receiver-operator characteristic curves for mean arterial pressure showed better predictive capacity for gestational hypertension than for preeclampsia. Sensitivity of mean arterial pressure to predict preeclampsia ranged between 39% and 48%, whereas for prediction of gestational hypertension it varied from 72% to 92%. Specificities for both groups were moderate (60% to 86%). Positive predictive values were low for all groups (5% to 33%). CONCLUSION: Elevated mean arterial pressure in the second half of pregnancy is a good predictor of gestational hypertension but is a poor predictor of preeclampsia.