Hypertension in pregnancy: which method of blood pressure measurement is most predictive of outcome?

Development of preeclampsia in pregnant women with white-coat hypertension: a systematic review and meta-analysis

OBJECTIVE

Hypertensive disorders during pregnancy are a significant cause of maternal and perinatal mortality and morbidity worldwide. White coat hypertension (WCH) is a hypertensive disease characterized by an increased clinic blood pressure but normal home or workplace blood pressure. Due to variable prevalence, a subset of women with WCH may be incorrectly diagnosed with chronic hypertension, highlighting the need for accurate diagnosis. Little is known about the role of WCH in pregnancy, but a meta-analysis aims to determine whether WCH increases the likelihood of developing preeclampsia.

METHODS

A systematic review and meta-analysis was conducted to determine whether there is an association between WCH and the incidence of preeclampsia in pregnant women. The search included PubMed, Embase, and Scopus databases until February 2023, using PRISMA guidelines. Pregnant women with apparent office hypertension throughout pregnancy who underwent 24-hour ambulatory blood pressure monitoring or home blood pressure monitoring were included. Meta-analysis was performed using RevMan.

RESULTS

This study included 12 studies with a total of 4,672 pregnant women and found that women with WCH have a higher risk of developing preeclampsia compared to normotensive women (RR: 2.29, 95% CI [1.18,4.43], P = 0.01). However, when compared with pregnant women with gestational hypertension or chronic hypertension, women with WCH had a significantly lower risk of developing preeclampsia ((RR: 0.39, [0.20,0.80], p=0.009) and (RR: 0.41, [0.27,0.62], P<0.001), respectively).

CONCLUSION

The study recommends incorporating 24-hour ABPM into clinical practice to differentiate between chronic hypertension and WCH in early pregnancy and focus on special management for those who need it. The findings may guide future research on ABPM's role in diagnosing WCH and its effects on pregnancy outcomes.

Practical guide for the management of hypertensive disorders during pregnancy

Hypertensive disorders of pregnancy, including gestational hypertension, preeclampsia, and eclampsia, are a worldwide health problem. Hypertensive disorders of pregnancy affect more than 10% of pregnancies and are associated with increased mortality and morbidity for both mother and fetus. Although patients' outcomes and family's experience will always be the primary concern regarding hypertensive complications during pregnancy, the economic aspect of this disease is also worth noting. Compared with normotensive pregnancies, those related with hypertension resulted in an excess increase in hospitalization and healthcare cost. Hence, the focus of this review is to analyze hypertensive disorders of pregnancy and to present practical tips with clear instructions for the clinical management of hypertensive disorders of pregnancy. This overview offers a detailed approach from the diagnosis to treatment and follow-up of a pregnant women with hypertension, evidence based, to support these instructions.

The assessment of blood pressure in pregnant women: pitfalls and novel approaches

Accurate assessment of blood pressure is fundamental to the provision of safe obstetrical care. It is simple, cost effective, and life-saving. Treatments for preeclampsia, including antihypertensive drugs, magnesium sulfate, and delivery, are available in many settings. However, the instigation of appropriate treatment relies on prompt and accurate recognition of hypertension. There are a number of different techniques for blood pressure assessment, including the auscultatory method, automated oscillometric devices, home blood pressure monitoring, ambulatory monitoring, and invasive monitoring. The auscultatory method with a mercury sphygmomanometer and the use of Korotkoff sounds was previously recommended as the gold standard technique. Mercury sphygmomanometers have been withdrawn owing to safety concerns and replaced with aneroid devices, but these are particularly prone to calibration errors and regular calibration is imperative to ensure accuracy. Automated oscillometric devices are straightforward to use, but the physiological changes in healthy pregnancy and pathologic changes in preeclampsia may affect the accuracy of a device and monitors must be validated. Validation protocols classify pregnant women as a "special population," and protocols must include 15 women in each category of normotensive pregnancy, hypertensive pregnancy, and preeclampsia. In addition to a scarcity of devices validated for pregnancy and preeclampsia, other pitfalls that cause inaccuracy include the lack of training and poor technique. Blood pressure assessment can be affected by maternal position, inappropriate cuff size, conversation, caffeine, smoking, and irregular heart rate. For home blood pressure monitoring, appropriate instruction should be given on how to use the device. The classification of hypertension and hypertensive disorders of pregnancy has recently been revised. These are classified as preeclampsia, transient gestational hypertension, gestational hypertension, white-coat hypertension, masked hypertension, chronic hypertension, and chronic hypertension with superimposed preeclampsia. Blood pressure varies across gestation and by ethnicity, but gestation-specific thresholds have not been adopted. Hypertension is defined as a sustained systolic blood pressure of ≥140 mm Hg or a sustained diastolic blood pressure of ≥90 mm Hg. In some guidelines, the threshold of diagnosis depends on the setting in which blood pressure measurement is taken, with a threshold of 140/90 mm Hg in a healthcare setting, 135/85 mm Hg at home, or a 24-hour average blood pressure on ambulatory monitoring of >126/76 mm Hg. Some differences exist among organizations with respect to the criteria for the diagnosis of preeclampsia and the correct threshold for intervention and target blood pressure once treatment has been instigated. Home blood pressure monitoring is currently a focus for research. Novel technologies, including early warning devices (such as the CRADLE Vital Signs Alert device) and telemedicine, may provide strategies that prompt earlier recognition of abnormal blood pressure and therefore improve management. The purpose of this review is to provide an update on methods to assess blood pressure in pregnancy and appropriate technique to optimize accuracy. The importance of accurate blood pressure assessment is emphasized with a discussion of preeclampsia prediction and treatment of severe hypertension. Classification of hypertensive disorders and thresholds for treatment will be discussed, including novel developments in the field.

[Ambulatory and Home Blood Pressure Measurement in Hypertensive Pregnant Women]

The prevalence of hypertensive disorders in pregnancy (HDP) is 6-8%. Blood pressure measurement (BPM) remains the cornerstone of diagnosis and should be performed in a standardised manner using automated devices. Office BPM represents only a spotty reading in an "artificial" environment failing to diagnose white coat hypertension (WCH). Ambulatory and home blood pressure measurement (ABPM/HBPM) are recommended for the diagnosis and differentiation of hypertension as well as for blood pressure and therapy control in women with HDP. Patient compliance is crucial for the use of both methods. ABPM is an appropriate method for the early identification of WCH and masked hypertension as well as for differentiating WCH from chronic hypertension < 20 week's gestation. HBPM has been shown to reduce the number of antenatal visits and hospital admissions compared to office blood pressure measurement without compromising maternal and fetal outcomes; it also avoids unnecessary antihypertensive medications and reduces the rate of labour inductions and false diagnosis of "preeclampsia". Problems associated with ABPM are its limited availability and inconvenience to patients due to sleep disturbances. Disadvantages of HBPM are the need for patient training, potential measurement errors, and the lack of evidence-based BP thresholds. The widespread use especially of HBPM may contribute to a reduction in workload of obstetric staff in the hospital and may save hospital expense.

Preeclampsia for the Nephrologist: Current Understanding in Diagnosis, Management, and Long-term Outcomes

Preeclampsia is a multisystem progressive disorder of pregnancy that can be potentially catastrophic for the mother and the fetus. It involves complex perturbations of the kidney and systemic physiology, along with long-term effects on vascular and kidney health. Thus, the nephrologist plays a key role in the peripartum and long-term management of preeclampsia. Recent translational research has improved our understanding of its pathophysiology, and there is hope for novel therapies. In this review, we discuss the evolution of diagnostic criteria and dilemmas in the diagnosis of hypertensive disorders in pregnancy. We summarize the advances in the pathogenesis and prediction of preeclampsia. We describe the management and prevention of preeclampsia focusing specially on the forthcoming strategies from the nephrologist's perspective. We address the evidence regarding long-term outcomes for the mother and the child. We end with exploring areas warranting future research.

Hypertension During Pregnancy

PURPOSE OF REVIEW

Hypertensive disorders of pregnancy affect about 5-10% of pregnancies impacting maternal, fetal, and neonatal outcomes. We review the recent studies in this field and discuss the pathophysiology, diagnosis, and management of hypertension during pregnancy, as well as the short- and long-term consequences on the cardiovascular health of women.

RECENT FINDINGS

Although the American College of Cardiology/American Heart Association revised their guidelines for hypertension in the general population in 2017, hypertension during pregnancy continues to be defined as a systolic blood pressure (SBP) ≥ 140 mmHg and/or a diastolic blood pressure (DBP) ≥ 90 mmHg, measured on two separate occasions. The addition of stage 1 hypertension will increase the prevalence of hypertension during pregnancy, identifying more women at risk of preeclampsia; however, more research is needed before changing the BP goal because a lower target BP has a risk of poor placental perfusion. Women with chronic hypertension have a higher incidence of superimposed preeclampsia, cesarean section, preterm delivery before 37 weeks' gestation, birth weight less than 2500 g, neonatal unit admission, and perinatal death. They also have a higher risk of developing cardiovascular disease later in life. The guidelines recommend low-dose aspirin for women with moderate and high risk of preeclampsia. While treating pregnant women with hypertension, the effectiveness of the antihypertensive agent must be balanced with risks to the fetus. Hypertensive disorders of pregnancy should be appropriately and promptly recognized and treated during pregnancy. They should further be co-managed by the obstetrician and cardiologist to decrease the long-term negative impact on the cardiovascular health of women.

Maternal and Perinatal Outcomes of White Coat Hypertension During Pregnancy: A Systematic Review and Meta-Analysis

The aim of this meta-analysis is to investigate whether white-coat hypertension (WCH) has an adverse effect on maternal, fetal, and neonatal outcomes. Medline, EMBASE, www.Clinicaltrials.gov, and Cochrane Library databases were searched electronically in December 2019. The outcomes were compared between pregnant women with WCH and normotensive controls, women with chronic hypertension, gestational hypertension or any hypertensive disorder of pregnancy. Twelve studies were eligible for inclusion in the systematic review. Women with WCH enrolled below 20 weeks had a significantly increased risk of preeclampsia (pooled risk ratio [RR], 5.43 [95% CI, 2.00-14.71]). Furthermore, women with WCH had increased risk of delivering a small-for-gestational-age newborn (RR, 2.47 [95% CI, 1.21-5.05], P=0.013) and preterm birth (RR, 2.86 [95% CI, 1.44-5.68], P=0.002). The risk of preeclampsia (risk ratio, 0.43 [95% CI, 0.23-0.78], P=0.005), small-for-gestational-age (RR, 0.46 [95% CI, 0.26-0.82], P=0.008), preterm birth (RR, 0.47 [95% CI, 0.31-0.71], P<0.001) were significantly lower with WCH compared with women with gestational hypertension. Women with WCH delivered ≈1 week later compared with women with chronic hypertension (mean difference, 1.06 weeks [95% CI, 0.44-1.67 weeks]; P<0.001). WCH is associated with a worse perinatal and maternal outcome than normotension, but better outcomes than gestational hypertension and chronic hypertension. Therefore, diagnosis of WCH should be ascertained in pregnant women presenting with hypertension. When the diagnosis is confirmed, these women require monitoring for developing preeclampsia, small-for-gestational-age and preterm birth.

Telemonitoring for hypertensive disease in pregnancy

Introduction: Telemonitoring of hypertension in pregnancy is becoming increasingly common. Several small studies have described the potential benefits of patient-led remote monitoring, including fewer hospital visits, better blood pressure control, and cost savings. Areas covered: This review summarises the principles of prenatal remote monitoring of hypertension as well as the types of devices and applications currently in use. We summarise current evidence regarding the potential benefits and pitfalls with respect to outcomes for mothers, neonates and wider population health. Core topics for ongoing and future research are discussed, with special emphasis on feasibility and validation of technologies, methodological standardization, patient safety, privacy and acceptability, and health economics and governance. Expert opinion: Telemonitoring of hypertension in pregnancy is likely to become commonplace in the next five to ten years and research now must be directed to ensure it is used in the safest way before its general introduction into daily clinical practice can be recommended. Raising women's awareness of their health condition could improve both pregnancy and long-term health outcomes.

Pregnancy outcomes following home blood pressure monitoring in gestational hypertension

OBJECTIVES

To assess the safety and efficacy of home blood pressure monitoring (HBPM) and office (traditional) blood pressure measurements in a cohort of pregnant women with gestational hypertension (GH).

STUDY DESIGN

This was a cohort study at St. George's Hospital, University of London conducted between December 2013 and August 2018. The inclusion criteria was pregnant women with a diagnosis of GH. Eligible patients were counseled and trained by a specialist midwife and were provided with an automated Microlife® "WatchBP Home" BP machine. Each patient followed an individualised schedule of hospital visits and BP measurements based on the HBPM pathway or standard hospital protocol which was based on the National Institute of Health and Care Excellence (NICE) guideline.

MAIN OUTCOME MEASURES

Adverse fetal, neonatal and maternal outcomes as well as number of antenatal hospital visits were recorded and compared between HBPM and office (traditional) pathways.

RESULTS

143 women with GH were included in the study (80 HBPM vs 63 standard care). There were no significant difference between the two groups in maternal high-dependency unit admission (P = 0.999), birth weight centile (P = 0.803), fetal growth restriction (p = 0.999), neonatal intensive care unit admissions (p = 0.507) and composite neonatal (p = 0.654), maternal (p = 0.999) or fetal adverse outcomes (p = 0.999). The number of Day Assessment Unit (DAU) visits was significantly lower in the HBPM group than the traditional pathway (median 4.0 vs. 5.0, P = 0.009). The difference was greater when the number of visits were adjusted for the duration of monitoring in weeks (median: 1.0 vs 1.5, P < 0.001). There were no significant difference between the two groups in the total number of outpatient (P = 0.357) and triage visits (p = 0.237). However, the total number of antenatal visits adjusted for the duration of monitoring was significantly lower for the HBPM group compared to the traditional pathway (median 1.4 vs 1.8, P = 0.020).

CONCLUSIONS

HBPM in women with GH results in significantly less antenatal visits compared to women on a standard pathway of care. The two groups had comparable fetal, neonatal and maternal adverse outcomes. Large multicentre studies are needed to ascertain the safety of rare adverse pregnancy outcomes.

Out of Office Blood Pressure Measurement in Pregnancy and the Postpartum Period

PURPOSE

Hypertensive disorders of pregnancy are increasing in prevalence and associated with significant maternal and perinatal morbidity and mortality.

RECENT FINDINGS

Increased emphasis has been placed recently on the use of out-of-office (i.e., home and ambulatory) blood pressure (BP) monitoring to diagnose and manage hypertension in the general population. Current guidelines offer limited recommendations on the use of out-of-office BP monitoring during pregnancy and postpartum. This review will discuss the recent literature on BP measurement outside of the office and its use for screening, diagnosis, and treatment in pregnancy and postpartum, and will illuminate areas for future research.

Hypertensive complications of pregnancy: A clinical overview

Hypertensive disorders in pregnancy are a worldwide health problem for women and their infants complicating up to 10% of pregnancies and associated with increased maternal and neonatal morbidity and mortality. In Europe, 2.3-3% of pregnancies are complicated by preeclampsia. Gestational diabetes, obesity, no previous or multiple births, maternal age less than 20 or greater than 35years old and thrombophilia can be some of the possible factors related to increased risk for hypertension in pregnancy. Complications of hypertension during pregnancy affect both mothers and their infants. Ambulatory blood pressure monitoring helps to distinguish true hypertension from the white coat as pregnant women with office abnormal values may have normal out of office blood pressure. Imbalance between proangiogenic and antiangiogenic factors in placenta may lead to endothelial dysfunction, vasoconstriction, activation of the coagulation system, and hemolysis. Carotid intima-media thickness, pulse wave velocity, augmentation index, and arterial wall tension were found to be significantly increased in women with preeclampsia compared to normotensive pregnant women. Uterine artery Doppler and serum biomarkers can be used to evaluate the probability of hypertension and complications during pregnancy, but further research in the field is needed. Lately, micro ribonucleic acids have also been the focus of research as potential biomarkers.

Home blood-pressure monitoring in a hypertensive pregnant population

OBJECTIVE

The majority of patients with chronic or gestational hypertension do not develop pre-eclampsia. Home blood-pressure monitoring (HBPM) has the potential to offer a more accurate and acceptable means of monitoring hypertensive patients during pregnancy compared with traditional pathways of frequent outpatient monitoring. The aim of this study was to determine whether HBPM reduces visits to antenatal services and is safe in pregnancy.

METHODS

This was a case-control study of 166 hypertensive pregnant women, which took place at St George's Hospital, University of London. Inclusion criteria were: chronic hypertension, gestational hypertension or high risk of developing pre-eclampsia, no significant proteinuria (≤ 1+ proteinuria on dipstick testing) and normal biochemical and hematological markers. Exclusion criteria were maternal age < 16 years, systolic blood pressure > 155 mmHg or diastolic blood pressure > 100 mmHg, significant proteinuria (≥ 2+ proteinuria on dipstick testing or protein/creatinine ratio > 30 mg/mmol), evidence of small-for-gestational age (estimated fetal weight < 10^th centile), signs of severe pre-eclampsia, significant mental health concerns or insufficient understanding of the English language. Pregnant women in the HBPM group were taught how to measure and record their blood pressure using a validated machine at home and attended every 1-2 weeks for assessment depending on clinical need. The control group was managed as per the local protocol prior to the implementation of HBPM. The two groups were compared with respect to number of visits to antenatal services and outcome.

RESULTS

There were 108 women in the HBPM group and 58 in the control group. There was no difference in maternal age, parity, body mass index, ethnicity or smoking status between the groups, but there were more women with chronic hypertension in the HBPM group compared with the control group (49.1% vs 25.9%, P = 0.004). The HBPM group had significantly fewer outpatient attendances per patient (6.5 vs 8.0, P = 0.003) and this difference persisted when taking into account differences in duration of monitoring (0.8 vs 1.6 attendances per week, P < 0.001). There was no difference in the incidence of adverse maternal, fetal or neonatal outcome between the two groups.

CONCLUSION

HBPM in hypertensive pregnancies has the potential to reduce the number of hospital visits required by patients without compromising maternal and pregnancy outcomes. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Blood pressure profile in pregnancy: The impact of its duration on results and patients' well-being

BACKGROUND

A blood pressure profile (BPP) is often used to diagnose and manage hypertension in pregnancy. However, there is no consensus on the number and interval of blood pressure (BP) readings required.

AIMS

To ascertain whether BP readings at 15-min interval over one hour yields clinically equivalent results to readings at 60-min interval over three hours.

MATERIALS AND METHODS

Eighty unique women were recruited to this prospective study. Automated BP machines were used to take readings at 15-min interval over one hour and at 60-min interval over three hours. The mean systolic and diastolic BPs obtained using each regimen were calculated and compared. Women also completed a questionnaire to evaluate the psychosocial and financial impact of a prolonged outpatient investigation.

RESULTS

BP readings from 67 patients were included for analysis. Clinical equivalence was assessed using the British Hypertension Society (BHS) validation criteria for comparing nonmercury devices to the gold-standard calibrated mercury device. Mean SBP readings for 54% (36/67), 90% (60/67) and 97% (65/67) and mean DBP readings for 73% (49/67), 94% (63/67) and 100% (67/67) were within 5, 10 and 15 mmHg agreement across the two time regimens which achieved grade B and grade A validation, respectively. A BPP was costly and stressful for women and affected their ability to attend work and look after other children.

CONCLUSIONS

A BPP performed over one hour compared to over three hours yields clinically equivalent results, yet has psychosocial and financial advantages.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Management of cardiovascular diseases during pregnancy

The prevalence of cardiovascular diseases (CVDs) in women of childbearing age is rising. The successes in medical and surgical treatment of congenital heart disease have led to an increasing number of women at childbearing age presenting with problems of treated congenital heart disease. Furthermore, in developing countries and in immigrants from these countries, rheumatic valvular heart disease still plays a significant role in young women. Increasing age of pregnant women and increasing prevalence of atherosclerotic risk factors have led to an increase in women with coronary artery disease at pregnancy. Successful management of pregnancy in women with CVDs requires early diagnosis, a thorough risk stratification, and appropriate management by a multidisciplinary team of obstetricians, cardiologists, anesthesiologists, and primary care physicians. The following review is based on the recent European guidelines on the management of CVDs during pregnancy, which aim at providing concise and simple recommendations for these challenging problems.

Prognostic value of ambulatory blood pressure measurements for the diagnosis of hypertension in pregnancy

Several studies have indicated that the use of the 24 h mean blood pressure, mainly using reference thresholds derived from general nonpregnancy practice, does not provide an effective test for an individualized early diagnosis of hypertension in pregnancy, thus concluding that ambulatory blood pressure monitoring is not a valid approach in pregnancy. With the use of ambulatory blood pressure monitoring, epidemiologic studies have reported gender differences in the circadian variability of blood pressure and heart rate. Typically, men exhibit a lower heart rate and higher blood pressure than women, the differences being larger for systolic than for diastolic blood pressure. Moreover, normotensive and hypertensive pregnant women are characterized by differing but predictable patterns of blood pressure variability throughout gestation. However, the diminished blood pressure in nongravid women as compared with men, the added decrease in blood pressure during the second trimester of gestation in normotensive but not in hypertensive pregnant women and the large amplitude of the circadian pattern that characterizes the blood pressure of healthy pregnant women at all gestational ages, have not been taken into account when establishing reference thresholds for the diagnosis of hypertension in pregnancy. This review will describe these issues, summarize previous results from independent groups on the prognostic value of ambulatory blood pressure monitoring in pregnancy, propose answers as to an accurate reference threshold for blood pressure at different stages of gestation and suggest how this information should be used in order to identify those women at a higher risk of hypertension, who will also be more suitable for prophylactic and/or therapeutic intervention in the early stages of pregnancy.

[Hypertension in pregnancy: the current state of the art]

Hypertension complicates 6-8% of pregnancies and includes the following four conditions: hypertension preceding pregnancy or documented before the 20th week of gestation; pre-eclampsia (PE)/eclampsia; chronic hypertension with superimposed pre-eclampsia; and gestational hypertension. The latter is defined as a significant rise in blood pressure after the 20th week of pregnancy in previously normotensive women, to over 140/90 mmHg. When blood pressure remains above 160/110 mmHg, it is considered severe. PE is defined as the presence of proteinuria (> or = 300 mg/24 h) in pregnant women with hypertension. The hypertensive syndromes of pregnancy are among the leading causes of maternal and fetal morbidity and mortality and anti-hypertensive treatment is part of the therapeutic arsenal used to prevent serious complications. Although the role of utero-placental insufficiency due to deficient migration of trophoblasts to the spiral arteries is universally accepted, the pathophysiology of PE remains largely unknown and is the subject of debate. No effective ways of predicting or preventing PE have been found, which highlights the need for further research in this field. This review aims primarily to evaluate recent advances in our understanding of the pathophysiology of gestational hypertension and especially PE, and new ways of predicting PE. Additionally, we present a brief review on the diagnosis, prevention and treatment of PE.

Association of three different techniques to measure blood pressure in the first trimester with the development of hypertensive disorders of pregnancy

OBJECTIVE

It is not known whether automated devices for measuring blood pressure perform better than conventional sphygmomanometry in predicting preeclampsia. This study compares two different automated devices with conventional sphygmomanometry for their association with development of preeclampsia or gestational hypertension.

DESIGN

Prospective observational cohort study.

SETTING

University hospital, Amsterdam, the Netherlands.

POPULATION

289 healthy normotensive women of whom 235 were nulliparous and 44 parous with preeclampsia in a previous pregnancy.

METHODS

At 8-11 weeks of pregnancy, blood pressure was measured with two different automated devices (continuous finger arterial pressure waveform registration and ambulatory blood pressure monitoring) and with conventional sphygmomanometry.

MAIN OUTCOME MEASURES

Preeclampsia and gestational hypertension.

RESULTS

Blood pressure in the first trimester, as measured with all three methods, was significantly higher in women who developed preeclampsia or gestational hypertension. After adjustment for previous preeclampsia, the point estimate of the odds ratios for association with later preeclampsia for both automated devices were comparable and higher than for conventional sphygmomanometry; however, differences were not statistically significant. The odds ratio (95% confidence intervals) for every 1 mmHg pressure increase of mean arterial pressure was 1.08 (1.02-1.15) for sphygmomanometry, 1.17 (1.09-1.27) for finger arterial pressure waveform registration, and 1.17 (1.07-1.27) for ambulatory blood pressure monitoring. Results were comparable if preeclampsia and gestational hypertension were analyzed together.

CONCLUSION

Blood pressure in the first trimester was associated with the development of hypertensive disorders of pregnancy. No significant differences were found between measurements by automatic devices compared with conventional sphygmomanometry.

Placental Pathology and Blood Pressure's Level in Women with Hypertensive Disorders in Pregnancy

Objective. The aim of this study was to investigate the extent of placental lesions associated with blood pressure (BP) levels in pregnancies complicated by hypertension. Methods. 55 singleton pregnancies complicated by mild hypertension were recruited and compared to 55 pregnancies complicated by severe hypertension. The histological assessment was carried out with regard to the following aspects: vessels number/field of vision, infarction, villous fibrinoid necrosis, villous hypermaturity, avascular villi, calcifications, lymphohistiocytic villitis, and thickened vessels. Statistical analysis was performed by SPSS. Results. All placental lesions were observed more often in the severe hypertension group. Vessels number was significantly decreased, and infarction and villous fibrinoid necrosis were significantly increased in the placentas of the severe hypertension group compared to the mild hypertension group (P < 0.001). Conclusion. This study supports that the extent of placental lesions in hypertensive pregnancies is correlated with hypertension level and so highlights blood pressure level as a mirror of placental function.

Twenty-four-hour ambulatory blood pressure monitor heart rate: a potential marker for gestational hypertension in at-risk women

We prospectively correlated the 24-hour ambulatory blood pressure measurements (ABPM) to conventional sphygmomanometer blood pressure measurements (CSM) in women at risk for gestational hypertensive disorders (GHTNDs) and identified predictive factors from ABPM for GHTND. We analyzed 73 women with ≥ 1 risk factor for developing a GHTND. Using both the CSM and ABPM, the systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), and heart rate (HR) were measured for 24 hours during three periods (14 to 24 weeks; 24 to 32 weeks; and 33 weeks to delivery). Correlation between the CSM and ABPM lessened as pregnancy progressed. Seventeen (25%) of women developed a GHTND. MAP variability increased in the GHTND group versus those without a GHTND. The odds of developing a GHTND increased 1.5 times for every 1 beat per minute increase in the ABPM 24-hour HR at visit 1 and reversed by visit 3. In women at risk for a GHTND, CSM and ABPM correlate less well as pregnancy advances. HR changes in at-risk women may be a marker for the development of a GHTND and may reflect increased sympathetic activity and/or decreased baroreceptor sensitivity.

Valoración prospectiva del test de tolerancia hiperbárica en el diagnóstico de hipertensión gestacional y preeclampsia

BACKGROUND AND OBJECTIVE

Recent studies have tried to overcome poor results from isolated blood pressure values in detecting hypertension in pregnancy by relying on ambulatory monitoring. Low sensitivity of the 24-hour mean has led many authors to conclude that ambulatory monitoring is not a valid approach in pregnancy. Against this background, we have evaluated prospectively the sensitivity and specificity in the diagnosis of gestational hypertension of the tolerance-hyperbaric test. This is a combined approach consisting of establishing tolerance intervals for the circadian variability of blood pressure as a function of gestational age, and then computing the hyperbaric index (area of blood pressure excess above the upper limit of the interval) by comparison of any patient's blood pressure profile with those limits.

PATIENTS AND METHOD

We studied 328 women who provided a 2014 blood pressure series. They were sampled for 48 hours once every 4 weeks from the first obstetric visit (mostly within the first trimester of gestation) until delivery. The hyperbaric index of each blood pressure series was calculated by taking into account the reference circadian tolerance limits established from a 497 series previously sampled from an independent reference group of 189 normotensive pregnant women.

RESULTS

Sensitivity of the tolerance-hyperbaric test was 91% for women sampled during the first trimester of gestation, and increased up to 99% in the third trimester. Specificity was above 99% in all trimesters. Positive and negative predictive values were above 96% in all trimesters. Moreover, the hyperbaric index provided an early identification of subsequent gestational hypertension and preeclampsia, on the average of 23 weeks prior to the clinical confirmation of the disease.

CONCLUSIONS

The tolerance-hyperbaric test represents a reproducible, stable, noninvasive, and high sensitivity test for the very early identification of subsequent gestational hypertension and preeclampsia, which can also be used as a guide for establishing prophylactic or therapeutic interventions.

The Value of Home Monitoring Kits in Diabetes, Hypertension, Asthma, and Oral Anticoagulation Therapy

Home monitoring devices encourage people to actively participate in their health care management. In addition, access to more data may help to make better decisions, which may ultimately lead to better health outcomes. The primary focus of this article will be on blood glucose, blood pressure, prothrombin time, and peak flow meters. The empirical evidence on the accuracy and usefulness of these home monitoring devices is discussed. Based on the evidence from the literature, erroneous reporting of the readings by the patients is a major concern. Therefore, primary practitioners are encouraged to consult with patients’ log books and their meters (if memory feature is available), instead of relying solely on self-reported values. Patients also need to be educated and trained adequately about the proper measurement technique and relevance and interpretation of the readings. Continuing education is necessary regarding the behavioral and therapeutic changes patients should carry out in accordance with performing regular home monitoring.

The safety of antihypertensives for treatment of pregnancy hypertension

This review addresses the maternal and perinatal benefits and risks of antihypertensive therapy in pregnancy. It covers the diagnosis of hypertension in pregnancy (with a brief discussion of ambulatory blood pressure measurement) followed by both the general principles of management of pregnancy hypertension and the specifics of individual antihypertensive drugs and drug classes. Discussion is focused on quantitative overviews of randomised, controlled trials, although observational literature is also discussed, particularly in reference to the potential teratogenicity of agents and the safety of their administration to nursing mothers. The treatment of severe hypertension is addressed separately from the treatment of mild-to-moderate hypertension, for which the maternal and fetal risks are substantially different.

Reproducibility of the tolerance-hyperbaric test for diagnosing hypertension in pregnancy

BACKGROUND

The tolerance-hyperbaric test has been shown to provide a valuable approach for the prediction of the outcome of pregnancy. In this test, diagnosis of hypertension is based on the hyperbaric index (area of blood pressure excess above the upper limit of a reference threshold) calculated by comparison with a time-specified tolerance interval for the circadian variability of blood pressure.

OBJECTIVE

To evaluate prospectively the stability and reproducibility of the tolerance-hyperbaric test.

METHODS

We studied 403 women who provided 2430 blood pressure series sampled for 48 consecutive hours once every 4 weeks from the first obstetric visit (mostly within the first trimester of gestation) until delivery. Circadian 90% tolerance limits for blood pressure were established as a function of trimester of gestation from 497 series previously sampled from an independent reference group of 189 normotensive pregnant women. Diagnosis of hypertension was established in this trial for each woman in the validation sample on the highly restricted basis of presenting at least one blood pressure profile with a hyperbaric index above the threshold for diagnosis after 20 weeks of gestation.

RESULTS

Sensitivity of the tolerance-hyperbaric test was 93% for women sampled during the first trimester of gestation, and increased to 99% by the third trimester. Specificity was more than 99% in all trimesters. The positive and negative predictive values were greater than 96% in all trimesters.

CONCLUSIONS

The tolerance-hyperbaric test represents a reproducible, stable, non-invasive and high-sensitivity test for the very early identification of subsequent hypertension in pregnancy.

Circadian rhythm of blood pressure challenges office values as the "gold standard" in the diagnosis of gestational hypertension

Despite poor sensitivity and specificity, office blood pressure (BP) determinations are still the "gold standard" for diagnosing gestational hypertension. This prospective blind study evaluates the prognostic value of office values as compared with ambulatory monitoring in pregnancy. We analyzed 2175 BP series systematically sampled from 355 non-preeclamptic pregnant women for 48 h every 4 wks from the first hospital visit until delivery. Women were divided for comparative purposes into three groups: "detected" gestational hypertension, defined on the basis of casual clinical BP> 140/90 mmHg after 20 wks of gestation and hyperbaric index (area of BP excess above the upper limit of a time-specified tolerance interval adjusted for the circadian pattern of the reference population) consistently above the threshold for diagnosing hypertension in pregnancy; "undetected" gestational hypertension, women with office BP < 140/90 mmHg but hyperbaric index consistently above the threshold for diagnosis; and normotension, women with both office values and hyperbaric index below the respective thresholds for diagnosis. Small and insignificant differences in the 24h mean BP between "detected" and "undetected" gestational hypertension is observed in all trimesters, in contrast with highly significant differences between these two groups and normotensive pregnancies. Normotensive women are characterized by highly significant lesser incidence by 60% in preterm delivery, 70% in intrauterine growth retardation, and 50% in delivery by cesarean section (p < 0.001) compared with women with "detected" and "undetected" gestational hypertension (p > 0.715). In pregnancy, the hyperbaric index is markedly superior to office BP measurements for diagnosis of what should be truly considered gestational hypertension, and for prediction of the outcome of pregnancy.

Prognostic value of office and ambulatory blood pressure measurements in pregnancy

With the objective to assess the prognostic value of office values as compared with ambulatory monitoring in pregnancy, we analyzed 2430 blood pressure series systematically sampled from 403 untreated pregnant women for 48 consecutive hours every 4 weeks from the first visit to the hospital until delivery. Women were divided into 5 groups: "detected" gestational hypertension, women with office blood pressures >140/90 mm Hg after 20 weeks of gestation and hyperbaric index (area of blood pressure excess above the upper limit of a time-specified tolerance interval) consistently above the threshold for diagnosing hypertension in pregnancy; "undetected" gestational hypertension, office values <140/90 mm Hg but hyperbaric index above the threshold for diagnosis; normotension, both office values and hyperbaric index below the thresholds for diagnosis; white coat hypertension, women with recorded diagnosis of gestational hypertension but hyperbaric index consistently below the threshold for diagnosis; and preeclampsia, defined as gestational hypertension and proteinuria. Results indicate small and nonsignificant differences in 24-hour mean of ambulatory pressures between "detected" and "undetected" gestational hypertension at all stages of pregnancy, in contrast with highly significant differences between these two groups and normotensive pregnancies. Average office blood pressure values were similar for preeclampsia, "detected," and "undetected" gestational hypertension. The hyperbaric index was, however, significantly higher for women with preeclampsia after 20 weeks of gestation as compared with all other groups and higher for women with either "detected" or "undetected" gestational hypertension as compared with normotensive pregnant women. The incidence of preterm delivery and intrauterine growth retardation were similar for "detected" and "undetected" gestational hypertension but significantly lower for normotensive women. In pregnancy, the hyperbaric index derived from ambulatory monitoring is markedly superior to office measurements for diagnosis of what should be truly considered gestational hypertension, as well as for prediction of the outcome of pregnancy.

Comparison of Portapres with standard sphygmomanometry in pregnancy

BACKGROUND

Continuous beat-to-beat noninvasive blood pressure (BP) measurement is possible with Portapres. It constructs finger arterial waveforms beat-to-beat. Dedicated software is used to analyze the arterial waveforms. A new technique has been developed to reconstruct brachial intra-arterial pressure that uses return to flow (RTF). This method has been validated against invasive intra-arterial measurements in nonpregnant individuals.

OBJECTIVES

To validate Portapres in normal and preeclamptic pregnant women against standard aneroid sphygmomanometry according to Riva-Rocci-Korotkoff (RRK).

METHODS

In 30 normotensive (10 in each trimester) and 20 preeclamptic women, two trained observers blinded from each other's results took BP measurements with a standard sphygmomanometer. These measurements were compared with sequential same-arm averaged measurements obtained during 30 sec by Portapres, following protocols from the Association for the Advancement of Medical Instrumentation (AAMI, mean accepted difference < or = 5 mmHg, SD < or = 8) and British Hypertension Society (BHS, gradings A down to D).

RESULTS

A total of 150 measurement pairs were analyzed. Cumulative percentages of absolute pressure differences for all women (BHS) and mean pressure differences (SD) for different trimesters and preeclampsia (AAMI) between sphygmomanometry and Portapres were calculated. Overall, mean difference (SD) for systolic BP was 5 (SD 8) and for diastolic BP was -3 (SD 8), although analysis of variance revealed a significant effect for preeclampsia on diastolic differences between the two methods of BP measurement ( p<0.001).

CONCLUSIONS

Portapres with RTF, developed to equal intra-arterial brachial pressure, compares reasonably well to RRK and overall meets the criteria set by the AAMI. According to the BHS, Portapres receives a B-grading for diastolic BP and a C-grading for systolic BP. As Portapres measures BP and calculates cardiac output continuously and noninvasively, it would appear worthwhile to further evaluate this device in pathological pregnancies.

Task Force II: blood pressure measurement and cardiovascular outcome

OBJECTIVE

To reach a consensus on the prognostic significance of new techniques of automated blood pressure measurement.

METHODS

A Task Force on the prognostic significance of ambulatory blood pressure monitoring wrote this review in preparation for the Eighth International Consensus Conference (28-31 October 2001, Sendai, Japan). This synopsis was amended to account for opinions aired at the conference and to reflect the common ground reached in the discussions.

POINTS OF CONSENSUS

(1) Prospective studies in treated and untreated hypertensive patients and in the general population have demonstrated that, even after adjusting for established risk factors, the incidence of cardiovascular events is correlated with blood pressure on conventional as well as ambulatory measurement. Ambulatory monitoring, however, significantly refines the prediction already provided by conventional blood pressure measurement. (2) White-coat hypertension is usually defined as an elevated clinic blood pressure in the presence of a normal daytime ambulatory blood pressure. Event-based studies in hypertensive patients have convincingly demonstrated that the risk of cardiovascular disease is less in patients with white-coat hypertension than in those with higher ambulatory blood pressure levels even after controlling for concomitant risk factors. Based on prognostic evidence, white-coat hypertension can now be defined as a conventional blood pressure that is persistently equal to or greater than 140/90 mmHg with an average daytime ambulatory blood pressure of below 135/85 mmHg. The issue of whether or not white-coat hypertension predisposes to sustained hypertension needs further research. (3) There is a growing body of evidence showing that a decreased nocturnal fall in blood pressure (<10% of the daytime level) is associated with a worse prognosis, irrespective of whether night-time dipping is studied as a continuous or a class variable. (4) Intermittent techniques of ambulatory blood pressure monitoring are limited in terms of quantifying short-term blood pressure variability. Proven cardiovascular risk factors such as old age, a higher than usual blood pressure and diabetes mellitus are often associated with greater short-term blood pressure variability. After adjusting for these risk factors, some - but not all - studies have nevertheless reported an independent and positive relationship between cardiovascular outcome and measures of variability of daytime and night-time blood pressure, for example standard deviation. (5) Reference values for ambulatory blood pressure measurement in children are currently based on statistical parameters of blood pressure distribution. In children and adolescents, functional rather than distribution-based definitions of ambulatory hypertension have yet to be developed. (6) Several studies of gestational hypertension have shown that, compared with office measurement, ambulatory blood pressure monitoring is a better predictor of maternal and fetal complications. Pregnancy is a special indication for ambulatory monitoring so that the white-coat effect can be measured and pregnant women are not given antihypertensive drugs unnecessarily. (7) Ambulatory pulse pressure and the QKD interval are measurements obtained by ambulatory monitoring that to some extent reflect the functional characteristics of the large arteries. The QKD interval is correlated with left ventricular mass, and ambulatory pulse pressure is a strong predictor of cardiovascular outcome. (8) Under standardized conditions, the self-measurement of blood pressure is equally as effective as ambulatory blood pressure monitoring in identifying the white-coat effect, but further studies are required to elucidate fully the prognostic accuracy of self-measured blood pressure in comparison with conventional and ambulatory blood pressure measurement.

CONCLUSIONS

Ambulatory blood pressure measurement refines the prognostic information provided by conventional blood pressure readings obtained in the clinic or the doctor's office. Longitudinal studies of patients with white-coat hypertension should clarify the transient, persistent or progressive nature of this condition, particularly in paediatric patients, in whom white-coat hypertension may be a harbinger of sustained hypertension and target-organ damage in adulthood. Finally, the applicability, cost-effectiveness and long-term prognostic accuracy of the self-measurement of blood pressure should be evaluated in relation to conventional blood pressure measurement and ambulatory monitoring.

Drugs in pregnancy. Antihypertensives

Fifty per cent of pregnancies are unplanned, and 1-6% of young women have pre-existing hypertension. However, no commonly used antihypertensive agent is known to be teratogenic. ACE inhibitors (and angiotensin-receptor antagonists) should be discontinued due to fetotoxicity. Five to 10% of pregnant women have hypertension, of which pre-existing hypertension is but one type. There is consensus that severe maternal hypertension (blood pressure >or=170/110 mmHg) should be treated to minimize the risk of acute cerebrovascular complications. Parenteral hydralazine may be associated with a higher risk of maternal hypotension, and intravenous labetalol with neonatal bradycardia. There is no consensus that mild-to-moderate hypertension in pregnancy should be treated. Clinical trials indicate that transient severe hypertension, antenatal hospitalization, proteinuria at delivery and neonatal respiratory distress syndrome may be decreased by normalizing blood pressure, but intrauterine fetal growth restriction may be increased. Methodological problems with published trials warrant cautious interpretation of these findings. Methyldopa and beta-blockers have been used most extensively, although atenolol may impair fetal growth in particular and should be avoided.

Overview of ambulatory blood pressure monitoring in childhood and pregnancy

Despite the fact that the study and applicability of ambulatory blood pressure in children and pregnant women share characteristics which limit the potential development of knowledge for their use, advances produced in the last few years provided the present knowledge regarding the significance and the potential use of ambulatory blood pressure in children and in the pregnant women. In children ambulatory blood pressure monitoring is useful for the diagnosis of mild hypertensives, assessment of refractory hypertension, therapeutic trials with antihypertensive drugs, and clinical investigation when BP is one of the parameters to be taken into account and/or when subtle BP abnormalities are the objective of the study. In pregnant women, the main applicability is to assess the maternal and fetal risk in the hypertensive disorders of pregnancy.

Treating hypertension in women of child-bearing age and during pregnancy

Hypertension is found among 1 to 6% of young women. Treatment aims to decrease cardiovascular risk, the magnitude of which is less dependent on the absolute level of blood pressure (BP) than on associated cardiovascular risk factors, hypertension-related target organ damage and/or concomitant disease. Lifestyle modifications are recommended for all hypertensive individuals. The threshold of BP at which antihypertensive therapy should be initiated is based on absolute cardiovascular risk. Most young women are at low risk and not in need of antihypertensive therapy. All antihypertensive agents appear to be equally efficacious; choice depends on personal preference, social circumstances and an agent's effect on cardiovascular risk factors, target organ damage and/or concomitant disease. Although most agents are appropriate for, and tolerated well by, young women, another consideration remains that of pregnancy, 50% of which are unplanned. A clinician must be aware of a woman's method of contraception and the potential of an antihypertensive agent to cause birth defects following inadvertent exposure in early pregnancy. Conversely, if an oral contraceptive is effective and well tolerated, but the woman's BP becomes mildly elevated, continuing the contraceptive and initiating antihypertensive treatment may not be contraindicated, especially if the ability to plan pregnancy is important (e.g. in type 1 diabetes mellitus). No commonly used antihypertensive is known to be teratogenic, although ACE inhibitors and angiotensin receptor antagonists should be discontinued, and any antihypertensive drugs should be continued in pregnancy only if anticipated benefits outweigh potential reproductive risk(s). The hypertensive disorders of pregnancy complicate 5 to 10% of pregnancies and are a leading cause of maternal and perinatal mortality and morbidity. Treatment aims to improve pregnancy outcome. There is consensus that severe maternal hypertension (systolic BP > or = 170mm Hg and/or diastolic BP > or = 110mm Hg) should be treated immediately to avoid maternal stroke, death and, possibly, eclampsia. Parenteral hydralazine may be associated with a higher risk of maternal hypotension, and intravenous labetalol with neonatal bradycardia. There is no consensus as to whether mild-to-moderate hypertension in pregnancy should be treated: the risks of transient severe hypertension, antenatal hospitalisation, proteinuria at delivery and neonatal respiratory distress syndrome may be decreased by therapy, but intrauterine fetal growth may also be impaired, particularly by atenolol. Methyldopa and other beta-blockers have been used most extensively. Reporting bias and the uncertainty of outcomes as defined warrant cautious interpretation of these findings and preclude treatment recommendations.

Blood pressure monitoring during pregnancy

Hypertensive disease in pregnancy represents a significant health problem in the world, and ranks second only to thromboembolism as a cause of maternal mortality in the USA. In addition, hypertension is associated with both perinatal morbidity and mortality secondary to direct effects on the fetus as well as the iatrogenic preterm deliveries performed for maternal indications. Conventional (office, mercury column or aneroid manometry) blood pressure measurement is the most common screening test performed during prenatal visits. During the past several years, investigators have focused on the use of 24-h ambulatory and automated self (or home) blood pressure monitoring during pregnancy. This review article summarizes the current literature on both ambulatory and home blood pressure monitoring in pregnancy and how they relate to various clinical aspects of hypertension in pregnancy.

Blood-pressure measurement and classification in pregnancy

Pre-eclampsia is usually defined on the basis of new onset hypertension and albuminuria developing after 20 weeks of pregnancy. There are difficulties with measurement of these variables. Conventional sphygmomanometry remains the gold standard for blood-pressure measurement. The value of ambulatory blood-pressure measurement has yet to be established. Oedema is now omitted from all definitions of preeclampsia, although the finding of widespread severe oedema of sudden onset should not be ignored for clinical purposes. Definitions of pre-eclampsia based solely on hypertension and proteinuria ignore the wide clinical variability in this syndrome. Women with no proteinuria but who do have hypertension and other features such as severe headache or other symptoms, thrombocytopenia, hyperuricaemia, disordered liver function, and fetal compromise are likely to have pre-eclampsia. This notion is accepted in the new Australasian definition of pre-eclampsia and more than hinted at in the new American College of Obstetricians and Gynecologists' definition. Definitions used for clinical purposes should be as safe as practical; they are likely to include a considerable number of false positives. Most research studies are weakened if patients without the disease are included. Therefore, a separate stringent research definition of pre-eclampsia we also suggest.

24-hour ambulatory blood pressure monitoring: a comparison between transdermal glyceryl-trinitrate and oral nifedipine

The objective of the present study is to compare the effectiveness of transdermal glyceryl-trinitrate versus oral nifedipine in lowering blood pressure in patients affected by pregnancy-induced hypertension (PIH). Thirty-six consecutive pregnant women have been evaluated at different gestational ages after the diagnosis of PIH or preeclampsia (PE). After a 24-h ambulatory blood pressure monitoring, patients were allocated to three groups: those receiving oral nifedipine and those receiving transdermal glyceryl-trinitrate in a continuous (24 h/day) or intermittent (16 h/day) administration. A second blood pressure monitoring was performed after 2 weeks of treatment. Systolic and diastolic blood pressure were compared by using the Cosinor method looking at mesor, amplitude, and acrophase. Baseline systolic and diastolic blood pressure was similar among the three groups. Neither the transdermal glyceryl-trinitrate administered for 24 or 16 h nor oral nifedipine affected systolic and diastolic blood pressure. Analysis of variance showed that the posttreatment values were similar among the groups. Further studies are needed to verify the possible use of transdermal glyceryl-trinitrate as an antihypertensive drug during pregnancy.

Ambulatory blood pressure monitoring in pregnancy

Hypertensive disorders of pregnancy remain a major cause of maternal and perinatal morbidity and mortality. Diagnosis and management of these disorders has relied on conventional blood pressure measurement, a technique fraught with error and uncertainty. Ambulatory blood pressure measurement is a promising new technique that has the potential to overcome the inaccuracies of conventional blood pressure measurement. Several ambulatory blood pressure monitors have been validated in pregnant populations, and normal reference ranges have been established. More recent research has focused on the potential clinical roles of ambulatory blood pressure measurement in pregnancy. This review addresses the limitations of conventional blood pressure measurement and reviews the current literature on the application of ambulatory blood pressure measurement in pregnancy.