Supplementary calcium in prevention of pre-eclampsia.

OBJECTIVE: To study the effect of calcium supplementation on reduction of pre-eclampsia in Iranian women at high risk of pre-eclampsia. METHODS: Thirty pregnant women at high risk of developing pre-eclampsia were randomized to 2 g of daily calcium and placebo. Subjects and investigators were blinded to treatment allocation. The inclusion criteria were positive rollover test, having at least one risk factor for pre-eclampsia, between 28 and 32 weeks of pregnancy, and blood pressure less than 140/90 (mm Hg). Exclusion criteria were having any chronic condition. Pre-eclampsia was defined as systolic/diastolic blood pressure over 140/90 plus proteinuria. All the subjects were followed up to delivery. RESULT: A sevenfold reduction in the occurrence of pre-eclamsia were seen among the calcium group compared with the placebo group (7 out of 15 developed pre-eclampsia in control group vs. 1 out of 15 in calcium group, P=0.014). No major effect on pregnancy induced hypertension was seen (66% in placebo and 76% in calcium group developed hypertension) but the onset of hypertension was delayed 3 weeks in the calcium group. A longer duration of pregnancy was seen in calcium than placebo (mean+/-S.D.=37+/-2 for calcium and 34+/-2 for placebo, P<0.05). Infants born to the calcium group, on average, were 552 g heavier than infants born to the placebo group, P<0.05. CONCLUSION: Calcium supplementation is beneficial for preventing pre-eclampsia among Iranian women at high risk of developing pre-eclampsia.     

Diet in pregnancy and the offspring's blood pressure 40 years later

Objective To determine how diet of the mother in pregnancy influences the blood pressure of the offspring in adult life.
Design A follow up study of men and women born during 1948–1954 whose mothers had taken part in a survey of diet in late pregnancy.
Setting Aberdeen, Scotland.
Population Two hundred and fifty-three men and women born in Aberdeen Maternity Hospital.
Main outcome measure Systolic and diastolic blood pressure.
Results The relations between the diet of mothers and their offsprings' blood pressure were complex. When the mothers' intake of animal protein was less than 50 g daily, a higher carbohydrate intake was associated with a higher blood pressure in the offspring (a 100 g increase in carbohydrate being associated with a 3 mmHg increase in systolic pressure (   P = 0.02  )). At daily animal protein intakes above 50 g, lower Carbohydrate intake was associated with higher blood pressure (a 100 g decrease in carbohydrate being associated with an 11 mmHg rise in systolic blood pressure (   P = 0.004  )). These increases in blood pressure were associated with decreased placental size.
Conclusion Mothers' intakes of animal protein and carbohydrate in late pregnancy may influence their offsprings' adult blood pressure. This may be mediated through effects on placental growth.     

The correlation between renal function and systolic or diastolic blood pressure in severe preeclamptic women.

OBJECTIVE: To evaluate the correlation between renal function and systolic or diastolic blood pressure in preeclamptic mothers. METHODS: In this prospective study from August 1998 to September 2002, 28 women >or= 28 weeks gestation with severe preeclampsia were selected. Meanwhile, 56 normotensive pregnant women without proteinuria or edema served as the control group. Urine was collected for 24 hours for all subjects. The concentration of uric acid, blood urea nitrogen, creatinine, sodium, calcium, and albumin in the 24-hour urine and blood of both groups were examined. Neonatal outcome also was evaluated. RESULTS:The serum and 24-hour urine concentration of blood urea nitrogen, creatinine, and albumin were significantly higher in severe preeclamptic women. Serum uric acid and urinary albumin/creatinine ratio was significantly higher in severe preeclamptic women compared with that in normotensive mothers and showed positive correlation with systolic or diastolic blood pressure. On the other hand, serum calcium/creatinine ratio was significantly lower in the severe preeclamptic group and negatively correlated to blood pressure. In multiple regressions, systolic or diastolic blood pressure was dependent on serum uric acid, albumin/creatinine, and calcium/creatinine ratios. Fetal birth weight was significantly lower in women with severe preeclampsia and with a lower Apgar score < 7 at 1 minute and 5 minutes and more preterm delivery compared with that in normotensive women. CONCLUSION: Renal function in women with severe preeclampsia was significantly impaired and highly correlated with systolic or diastolic blood pressure.     

Calcium supplementation reduces the risk of pregnancy-induced hypertension in an Andes population

Previous studies have suggested that increased dietary calcium is associated with a decreased occurrence of pregnancy-induced hypertension. In this study 106 young healthy nulliparous women, residing in Quito, Ecuador, were enrolled in a double-blind, randomized, controlled clinical trial. From 24 weeks gestation until delivery they received either 2 g of elemental calcium per day or a placebo. Calcium supplementation was associated with a significantly decreased risk of pregnancy-induced hypertension, with 4.1% developing pregnancy-induced hypertension in the treatment group versus 27.9% in the placebo group. Treatment was associated with a decrease in both systolic and diastolic blood pressure over the course of pregnancy. In addition, there was a small but significant increase in serum ionized calcium levels in the calcium-supplemented group during the treatment period.     

Calcium supplementation reduces the risk of pregnancy-induced hypertension in an Andes population

Summary. Previous studies have suggested that increased dietary calcium is associated with a decreased occurrence of pregnancy-induced hypertension. In this study 106 young healthy nulliparous women, residing in Quito, Ecuador, were enrolled in a double-blind, randomized, controlled clinical trial. From 24 weeks gestation until delivery they received either 2 g of elemental calcium per day or a placebo. Calcium supplementation was associated with a significantly decreased risk of pregnancy-induced hypertension, with 4.1% developing pregnancy-induced hypertension in the treatment group versus 27.9% in the placebo group. Treatment was associated with a decrease in both systolic and diastolic blood pressure over the course of pregnancy. In addition, there was a small but significant increase in serum ionized calcium levels in the calcium-supplemented group during the treatment period.     

The white coat effect in hypertensive pregnancy: much ado about nothing?

OBJECTIVES: To determine the prevalence of white coat hypertension and white coat effect among hypertensive pregnant women and to assess whether the presence of a significant white coat effect was associated with adverse pregnancy outcome when clinical management was based upon standard sphygmomanometric blood pressure recordings. DESIGN: Prospective blinded studies assessing the presence of a white coat effect. SETTING: Antenatal ward and pregnancy day assessment unit of St George Hospital, a teaching hospital in Sydney, Australia. POPULATION: One hundred and twenty-one hypertensive pregnant women in the second half of their pregnancy admitted to hospital or the day assessment unit for management of their hypertensive disorders. METHODS: Routine sphygmomanometric blood pressures were recorded by midwives in the ward or day assessment unit and awake blood pressure recordings were averaged. These blood pressures were compared with average awake blood pressures recorded by ambulatory blood pressure monitor (ABPM) (Spacelabs 90207, Seattle, Washington, USA). White coat hypertension was defined as an average sphygmomanometer blood pressure > or = 140 mmHg systolic and/or > or = 90 mmHg diastolic with awake ABPM average blood pressure within the normal range for ABPM-derived blood pressures in pregnancy, according to gestation. White coat effect was the difference between average sphygmomanometer blood pressure and average awake ABPM-derived blood pressure. All clinical management was based upon routine sphygmomanometer recordings and clinicians were blinded to ABPM data. MAIN OUTCOME MEASURES: Prevalence of white coat hypertension and white coat effect; maternal and fetal outcomes in those with and without a white coat effect of > or = 20 mmHg systolic and/or > or = 10 mmHg diastolic. RESULTS: Systolic and diastolic white coat hypertension were present in only 3.2% and 4.2% of the group, respectively. A systolic white coat effect > or = 20 mmHg was found in only 4.2% but 20.2% (26% for day assessment unit patients vs 15% for inpatients; P = 0.17) had a diastolic white coat effect > or = 10 mmHg. There was no difference in maternal or fetal outcomes between women with and without a white coat effect. CONCLUSIONS: White coat hypertension is an infrequent occurrence in mildly hypertensive pregnant women. Although a white coat effect is present more often, this is associated with clinical outcomes similar to women who do not exhibit this phenomenon. Using ABPM to identify a white coat effect in women presenting with hypertension in the second half of their pregnancy does not appear to be clinically useful.     

Risk factors associated with preeclampsia in healthy nulliparous women

Objective: Our goal was to identify risk factors for the development of preeclampsia in nulliparous women enrolled in a multicenter trial comparing calcium supplementation to a placebo. Study Design: A total of 4589 women from five centers was studied. Analysis of risk factors for preeclampsia was performed in 4314 who carried the pregnancy to >20 weeks. Baseline systolic and diastolic blood pressure, demographic characteristics, and findings after randomization were examined for the prediction of preeclampsia. Preeclampsia was defined as hypertension (diastolic blood pressure ≥90 mm Hg on two occasions 4 hours to 1 week apart) and proteinuria (≥300 mg/24 hours, a protein/creatinine ratio ≥0.35, one dipstick measurement ≥2+ or two dipstick measurements ≥1+ at an interval as specified for diastolic blood pressure). Results: Preeclampsia developed in 326 women (7.6%). The first analysis treated each risk factor as a categoric variable in a univariate regression. Maternal age, blood group and Rh factor, alcohol use, previous abortion or miscarriage, private insurance, and calcium supplementation were not statistically significant. Risk factors initially found to be significant were body mass index, systolic blood pressure, diastolic blood pressure, non-white race (African-American and other), clinical center, and smoking. Adjusted odds ratios computed with a Iogistic regression model revealed that body mass index (odds ratio 3.22 for ≥35 kg/m² vs <19.8 kg/m²), systolic blood pressure (odds ratio 2.66 for ≥120 vs <101 mm Hg), diastolic blood pressure (odds ratio 1.72 for ≥61 mm Hg vs <60 mm Hg), and clinical center (odds ratio 1.85 for Memphis vs the other clinical centers) were statistically significant predictors of preeclampsia. Results of the final model fit revealed that preeclampsia risk increases significantly (p < 0.0001) with increased body mass index at randomization, as well as with increased systolic and diastolic blood pressure at randomization. Calcium supplementation had no effect on the risks posed by body mass index and blood pressure. Among risk factors developing after randomization, an abnormal result of a glucose screen (plasma glucose ≥140 mg/dl 1 hour after a 50 gm glucose challenge) was not found to be associated with a significant risk of preeclampsia. Conclusion: These risk factors should be of value in counseling women regarding preeclampsia and should aid in understanding the pathophysiologic characteristics of this syndrome.     

The Correlation Between Renal Function and Systolic or Diastolic Blood Pressure in Severe Preeclamptic Women

Objective. To evaluate the correlation between renal function and systolic or diastolic blood pressure in preeclamptic mothers. Methods. In this prospective study from August 1998 to September 2002, 28 women ≥ 28 weeks gestation with severe preeclampsia were selected. Meanwhile, 56 normotensive pregnant women without proteinuria or edema served as the control group. Urine was collected for 24 hours for all subjects. The concentration of uric acid, blood urea nitrogen, creatinine, sodium, calcium, and albumin in the 24-hour urine and blood of both groups were examined. Neonatal outcome also was evaluated. Results. The serum and 24-hour urine concentration of blood urea nitrogen, creatinine, and albumin were significantly higher in severe preeclamptic women. Serum uric acid and urinary albumin/creatinine ratio was significantly higher in severe preeclamptic women compared with that in normotensive mothers and showed positive correlation with systolic or diastolic blood pressure. On the other hand, serum calcium/creatinine ratio was significantly lower in the severe preeclamptic group and negatively correlated to blood pressure. In multiple regressions, systolic or diastolic blood pressure was dependent on serum uric acid, albumin/creatinine, and calcium/creatinine ratios. Fetal birth weight was significantly lower in women with severe preeclampsia and with a lower Apgar score < 7 at 1 minute and 5 minutes and more preterm delivery compared with that in normotensive women. Conclusion. Renal function in women with severe preeclampsia was significantly impaired and highly correlated with systolic or diastolic blood pressure.     

Ambulatory blood pressure monitoring and active renin in menopausal women treated with amlodipine and hormone replacement therapy.

The aim of this study was to follow up the effect of an 8-week treatment with amlodipine given alone or in combination with hormone replacement therapy (HRT) on blood pressure and active renin in postmenopausal women with mild to moderate arterial hypertension using both conventional clinical blood pressure measurements and ambulatory blood pressure monitoring. Twenty-nine hypertensive menopausal women were divided randomly into two groups according to the treatment regimens: amlodipine and amlodipine plus HRT. The combination with HRT led to normalization of 24-h and daytime systolic and diastolic blood pressure. In contrast to the group treated with amlodipine alone, where a significant fall only of systolic night-time blood pressure was observed, in the group treated with amlodipine plus HRT both systolic and diastolic night-time blood pressure decreased significantly. Active renin did not change significantly after treatment in both groups. Triglycerides decreased significantly and high-density lipoprotein-cholesterol increased significantly only after amlodipine treatment. There were no significant differences in serum total cholesterol and low-density lipoprotein-cholesterol after HRT plus amlodipine. In conclusion, amlodipine is effective in reducing blood pressure in postmenopausal women. The maintenance of a normal circadian blood pressure pattern was influenced by HRT.     

Ambulatory blood pressure monitoring and active renin in menopausal women treated with amlodipine and hormone replacement therapy

The aim of this study was to follow up the effect of an 8-week treatment with amlodipine given alone or in combination with hormone replacement therapy (HRT) on blood pressure and active renin in postmenopausal women with mild to moderate arterial hypertension using both conventional clinical blood pressure measurements and ambulatory blood pressure monitoring. Twenty-nine hypertensive menopausal women were divided randomly into two groups according to the treatment regimens: amlodipine and amlodipine plus HRT. The combination with HRT led to normalization of 24-h and daytime systolic and diastolic blood pressure. In contrast to the group treated with amlodipine alone, where a significant fall only of systolic night-time blood pressure was observed, in the group treated with amlodipine plus HRT both systolic and diastolic night-time blood pressure decreased significantly. Active renin did not change significantly after treatment in both groups. Triglycerides decreased significantly and high-density lipoprotein-cholesterol increased significantly only after amlodipine treatment. There were no significant differences in serum total cholesterol and low-density lipoprotein-cholesterol after HRT plus amlodipine. In conclusion, amlodipine is effective in reducing blood pressure in postmenopausal women. The maintenance of a normal circadian blood pressure pattern was influenced by HRT.     

Effect of calcium and vitamin D supplementation on toxaemia of pregnancy

To study the effect of calcium and vitamin D supplementation on the incidence of toxaemia of pregnancy, 200 randomly selected pregnant women (supplemented group), were put on calcium (375 mg/day) and vitamin D (1,200 IU/day) supplements at 20-24 weeks of pregnancy onwards. Another 200 pregnant women constituted the non-supplemented group. At 32 and 36 weeks of pregnancy the systolic and diastolic blood pressure of non-toxemic women was significantly lower in the supplemented group than in the non-supplemented group. However, the incidence of toxaemia in the supplemented group (6%) was not significantly different from that in the non-supplemented group (9%).     

Flow velocity waveforms in uterine and umbilical arteries during the angiotensin II sensitivity test

The angiotensin II sensitivity test has been used to predict the development of hypertension during pregnancy. We investigated the systolic/diastolic ratios of flow velocity waveforms in the uterine and umbilical arteries by means of a color Doppler system in 15 healthy women at 24 to 26 weeks' gestation. A significant increase (p less than 0.001) was observed in the systolic/diastolic ratio in the uterine artery, which was unaffected by the location of the placenta. In five women a differential effect of angiotensin II on the systemic diastolic blood pressure and on the systolic/diastolic was observed: the uterine circulation appeared to have a slower response and a faster recovery than the diastolic blood pressure. No changes in the systolic/diastolic ratio in the umbilical artery were observed.     

Effects of fish oil supplementation in late pregnancy on blood pressure: a randomised controlled trial

Objective To study the effect of fish oil supplementation on blood pressure during the third trimester of pregnancy.
Design In the 30th week of pregnancy 533 healthy women were randomly assigned in a ratio 2:1:1 to receive fish oil (2–7 g/day n-3 fatty acids (Pikasol)), or a control regimen of either olive oil or no oil supplementation.
Main Outcome measures Blood pressure measured with an automatic device (Dinamap 1846 SX, Criticon) at baseline and in weeks 33, 37, 39 and subsequently weekly until delivery.
Results Mean blood pressure increased during the third trimester, and this was not influenced by group assignment. No significant effects on either systolic or diastolic blood pressure were seen in the fish oil group compared to the control groups. The proportions of women with a systolic blood pressure above 140 mmHg or a diastolic blood pressure above 90 mmHg were not significantly different in the fish oil group compared with the control groups, although the proportion of women with diastolic above 90 mmHg tended to be lower in the fish oil group compared with the olive oil group. The corresponding relative risk was RR = 048 (95 % CI 0.22–1.06;   P = 007  ).
Conclusion 2.7 g/day of marine n-3 fatty acids provided in the third trimester of normal pregnancy showed no effect on blood pressure.     

A prediction model for superimposed preeclampsia in women with chronic hypertension during pregnancy

OBJECTIVE: Women with chronic hypertension are at increased risk for superimposed preeclampsia. We developed a prediction algorithm for superimposed preeclampsia using clinical and laboratory information that were measured early in pregnancy. STUDY DESIGN: A secondary analysis of data that were collected from 110 women with chronic hypertension who were enrolled in a trial of calcium supplementation was performed. Blood pressure, the renin-angiotensin system, and calcium metabolism were assessed at 12, 20, 28, and 36 weeks of gestation and 6 weeks after delivery. Multivariable logistic regression was used to develop the predictive model. RESULTS: Thirty-seven women had superimposed preeclampsia. The final model included systolic blood pressure, serum uric acid, and plasma renin activity, which were all measured at 20 weeks of gestation. Women with high systolic blood pressure (>140 mm Hg), elevated uric acid (>3.6 mg/dL), and low plasma renin activity (<4 ng/mL/hr) had an 86% probability of having superimposed preeclampsia. Women with 2 risk factors had a 62% probability of superimposed preeclampsia, and women with only 1 risk factor had a 30% to 40% probability of superimposed preeclampsia. CONCLUSION: We developed a prediction algorithm that can be validated in future studies for superimposed preeclampsia for women with chronic hypertension.     

A randomized trial of tight vs. less tight control of mild essential and gestational hypertension in pregnancy

Abstract Objectives: To assess the effects of applying a tight vs. a less tight control of mild chronic essential or gestational non-proteinuric hypertension in pregnancy. Methods: A randomized trial was conducted in 2006-2007 in the University of Ain Shams, Egypt. Eligible participants (n=125) were randomly assigned to either tight or less tight control of mild chronic (essential) or gestational (non-proteinuric) hypertension. The primary outcome measure was the development of severe hypertension during follow-up. Analysis was by intention-to-treat. Results: In the tight target group, adjustment of the dose with an increment of 191 mg yielded a mean dose of methyldopa of 1267+/-406 mg. Both systolic and diastolic BP levels were significantly less than in the tight target group. More women in the less tight group had severe hypertension during follow up (RR 3.167 and 95% CI 1.36-7.37). The rate of antenatal hospitalization was significantly higher in the less tight target group with a relative risk of 2.57 and 95% CI 1.16-5.70. The gestational age at delivery was significantly better in the tight target group. Preterm delivery and birth weight were not significantly different between the study groups. Conclusion: Tight control of blood pressure reduces the rate of antenatal hospitalization and does not adversely affect perinatal outcomes in women with mild essential or gestational hypertension.     

Independent association between leptin and blood pressure during third trimester in normal and gestational diabetic pregnancies

OBJECTIVE: To assess the relationship between plasma leptin concentration during third trimester of pregnancy and blood pressure, independent of body mass index at examination and other potential confounders. STUDY DESIGN: A cross-sectional study was performed including 95 women (61 non-diabetic women, 34 women with gestational diabetes (GD)) in their third trimester of pregnancy. The relationship between plasma leptin and blood pressure was investigated using multiple linear regression analysis. RESULTS: Independent of body mass index (BMI), leptin was positively correlated to systolic (P = 0.024) and diastolic blood pressure (P = 0.002). Stepwise linear regression identified leptin as the only variable independently associated with systolic blood pressure (P = 0.003), while leptin (P < 0.001) and age (P = 0.024) were the only variables independently correlated to diastolic blood pressure. CONCLUSIONS: This study reports for the first time that, independent of BMI at examination, presence of GD or other confounders, plasma leptin is positively correlated with blood pressure in pregnant women.     

Home blood pressure levels in pregnant women with chronic hypertension.

OBJECTIVE: To explore the difference between office and home blood pressure (BP) monitoring in normotensive and hypertensive pregnant women. METHODS: We compared the mean of 1 week home BP with office BP, measured by aneroid devices, in 20 normotensive women (68 BP assessments) and 100 women with mild essential chronic hypertension without superimposed gestational hypertension (429 BP assessments). Different approaches were used including the Bland-Altman method to investigate the discrepancies between office and home BP. RESULTS: Systolic office BP in normotensive women (p = 0.004) and diastolic office BP in hypertensive women (p = 0.001) were lower than home BP. The concordance between office and home BPs was better for diastolic BP than for systolic BP. Only a small number of hypertensive women presented home BP >or=135/85 mm Hg. CONCLUSIONS: In our study population, the concurrence between office and home BPs is good with the exception of systolic BP in normotensive women. Home blood pressure measurement criteria used in nonpregnant individuals are not adequate in pregnancy.     

Inter-arm blood pressure differences in pregnant women

Objective  To determine the prevalence of blood pressure inter-arm difference (IAD) in early pregnancy and to investigate its possible association with maternal characteristics.
Design  A cross-sectional observational study.
Setting  Routine antenatal visit in a university hospital.
Population  A total of 5435 pregnant women at 11–14 weeks of gestation.
Methods  Blood pressure was taken from both arms simultaneously with a validated automated device.
Main outcome measures  The presence of inter-arm blood pressure difference of 10 mmHg or more.
Results  The IAD in systolic and diastolic blood pressure was 10 mmHg or more in 8.3 and 2.3% of the women, respectively. Systolic IAD was found to be significantly related to systolic blood pressure and pulse pressure, and diastolic IAD was found to be significantly related to maternal age, diastolic blood pressure and pulse pressure. The systolic and diastolic IAD were higher in the hypertensive group compared with the normotensive group and absolute IAD increased with increasing blood pressure. About 31.0 and 23.9% of cases of hypertension would have been underreported if the left arm and the right arm were used, respectively, in measuring the blood pressure.
Conclusions  There is a blood pressure IAD in a significant proportion of the pregnant population, and its prevalence increases with increasing blood pressure. By measuring blood pressure only on one arm, there is a one in three chance of underreporting hypertension. Therefore, it would be prudent that during the booking visit blood pressure should be taken in both arms and thus provide guidance for subsequent blood pressure measurements during the course of pregnancy.     

Accuracy of Automated Blood Pressure Recorders in Pregnancy

Summary: Automated blood pressure recorders are used with increasing frequency by pregnant women, mostly without proper evaluation of their accuracy. We compared blood pressures (BP) recorded by 2 automated noninvasive devices, the Spacelabs 90207 ambulatory blood pressure monitor and the OMRON HEM 705 CP portable selfinitiated device, with blood pressures recorded by routine sphygmomanometry in 79 pregnant women either considered 'at risk' for preeclampsia or with mild hypertension in pregnancy. The Spacelabs device tended to overestimate systolic BP by a mean 11 (SD = 8) mmHg and diastolic BP by 5 (SD = 7) mmHg for phase 5 pressure (p < 0.001) but was similar to routine BPs for diastolic phase 4 pressures. The OMRON device tended to underestimate diastolic (phase 4) pressure by 4 (SD = 6) mmHg (p < 0.001) but gave similar systolic and diastolic (phase 5) pressures to routine sphygmomanometry. However, for both devices there was considerable individual patient variability in accuracy. When using these devices to record a limited number of blood pressure recordings, as in this study, we suggest that individual comparison with mercury sphygmomanometry be made in each pregnant woman before accepting the validity of these recordings.