Labetalol vs. methyldopa in the treatment of pregnancy-induced hypertension

Preeclampsia: state of art and future perspectives. A special focus on possible preventions

Preeclampsia (PE) is characterised by the new onset of hypertension after the 20th week of pregnancy, with or without proteinuria or hypertension that leads to end-organ dysfunction. Since the only definitive treatment is delivery, PE still represents one of the leading causes of preterm birth and perinatal mobility and mortality. Therefore, any strategies that aim to reduce adverse outcomes are based on early primary prevention, prenatal surveillance and prophylactic interventions. In the last decade, intense research has been focussed on the study of predictive models in order to identify women at higher risk accurately. To date, the most effective screening model is based on the combination of anamnestic, demographic, biophysical and maternal biochemical factors. In this review, we provide a detailed discussion about the current and future perspectives in the field of PE. We will examine pathogenesis, risk factors and clinical features. Moreover, recent developments in screening and prevention strategies, novel therapies and healthcare management strategies will be discussed.

Pharmacotherapy for hypertension in pregnant patients: special considerations

INTRODUCTION

Hypertensive disorders of pregnancy (HDP) represent a major cause of maternal, fetal and neonatal morbidity and mortality and identifies women at risk for cardiovascular and other chronic diseases later in life. When antihypertensive drugs are used during pregnancy, their benefit and harm to both mother and fetus should be evaluated.

AREAS COVERED

This review summarizes the pharmacological characteristics of the recommended antihypertensive drugs and their impact on mother and fetus when administered during pregnancy and/or post-partum. Drugs were identified using MEDLINE and the main international Guidelines for the management of HDP.

EXPERT OPINION

Although there is a consensus that severe hypertension should be treated, treatment of mild hypertension without end-organ damage (140-159/90-109 mmHg) remains controversial and there is no agreement on when to initiate therapy, blood pressure targets or recommended drugs in the absence of robust evidence for the superiority of one drug over others. Furthermore, the long-term outcomes of in-utero antihypertensive exposure remain uncertain. Therefore, evidence-based data regarding the treatment of HDP is lacking and well designed randomized clinical trials are needed to resolve all these controversial issues related to the management of HDP.

Current and emerging pharmacotherapy for emergency management of preeclampsia

INTRODUCTION

Preeclampsia is a disease specific to pregnancy characterised by new onset hypertension with maternal organ dysfunction and/or fetal growth restriction. It remains a major cause of maternal and perinatal morbidity and mortality. For fifty years, antihypertensives have been the mainstay of treating preeclampsia, reducing maternal morbidity and mortality. With increased knowledge of the mechanisms underlying the disease has come opportunities for novel therapies that complement antihypertensives by protecting the maternal vasculature. Areas covered: In this review, the authors consider, in detail, the antihypertensives commonly used today in the emergency care of women with severe preeclampsia. They also review less common anti-hypertensive agents and discuss the role of magnesium sulphate in the management of preeclampsia and the prevention of eclampsia. Finally, they explore novel therapeutics for the acute management of preeclampsia. Expert opinion: The rapid control of maternal hypertension will, and must, remain the mainstay of emergency treatment for women with severe preeclampsia. The role of magnesium sulphate as a primary prevention for eclampsia is context dependant and should not displace a focus on correcting blood pressure safely. The exploration of novel adjuvant therapies will likely allow us to prolong pregnancy longer and improve perinatal outcomes safely for the mother.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve pregnancy outcome. This Cochrane Review is an updated review, first published in 2001 and subsequently updated in 2007 and 2014.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (13 September 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy, defined as systolic blood pressure 140 to 169 mmHg and/or diastolic blood pressure 90 to 109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.

MAIN RESULTS

For this update, we included 63 trials (data from 58 trials, 5909 women), with moderate to high risk of bias overall.We carried out GRADE assessments for the main 'antihypertensive drug versus placebo/no antihypertensive drug' comparison only. Evidence was graded from very low to moderate certainty, with downgrading mainly due to design limitations and imprecision.For many outcomes, trials contributing data evaluated different hypertensive drugs; while we did not downgrade for this indirectness, results should be interpreted with caution.Antihypertensive drug versus placebo/no antihypertensive drug (31 trials, 3485 women)Primary outcomes: moderate-certainty evidence suggests that use of antihypertensive drug(s) probably halves the risk of developing severe hypertension (risk ratio (RR) 0.49; 95% confidence interval (CI) 0.40 to 0.60; 20 trials, 2558 women), but may have little or no effect on the risk of proteinuria/pre-eclampsia (average risk ratio (aRR) 0.92; 95% CI 0.75 to 1.14; 23 trials, 2851 women; low-certainty evidence). Moderate-certainty evidence also shows that antihypertensive drug(s) probably have little or no effect in the risk of total reported fetal or neonatal death (including miscarriage) (aRR 0.72; 95% CI 0.50 to 1.04; 29 trials, 3365 women), small-for-gestational-age babies (aRR 0.96; 95% CI 0.78 to 1.18; 21 trials, 2686 babies) or preterm birth less than 37 weeks (aRR 0.96; 95% CI 0.83 to 1.12; 15 trials, 2141 women).

SECONDARY OUTCOMES

we are uncertain of the effect of antihypertensive drug(s) on the risk of maternal death, severe pre-eclampsia, or eclampsia, orimpaired long-term growth and development of the baby in infancy and childhood, because the certainty of this evidence is very low. There may be little or no effect on the risk of changed/stopped drugs due to maternal side-effects, or admission to neonatal or intensive care nursery (low-certainty evidence). There is probably little or no difference in the risk of elective delivery (moderate-certainty evidence).Antihypertensive drug versus another antihypertensive drug (29 trials, 2774 women)Primary outcomes: beta blockers and calcium channel blockers together in the meta-analysis appear to be more effective than methyldopa in avoiding an episode of severe hypertension (RR 0.70; 95% CI 0.56 to 0.88; 11 trials, 638 women). There was also an increase in this risk when other antihypertensive drugs were compared with calcium channel blockers (RR 1.86; 95% CI 1.09 to 3.15; 5 trials, 223 women), but no evidence of a difference when methyldopa and calcium channel blockers together were compared with beta blockers (RR1.18, 95% CI 0.95 to 1.48; 10 trials, 692 women). No evidence of a difference in the risk of proteinuria/pre-eclampsia was found when alternative drugs were compared with methyldopa (aRR 0.78; 95% CI 0.58 to 1.06; 11 trials, 997 women), with calcium channel blockers (aRR: 1.24, 95% CI 0.70 to 2.19; 5 trials, 375 women), or with beta blockers (aRR 1.21, 95% CI 0.88 to 1.67; 12 trials, 1107 women).For the babies, we found no evidence of a difference in the risk oftotal reported fetal or neonatal death (including miscarriage) when comparing other antihypertensive drugs with methyldopa (aRR 0.77, 95% CI 0.52 to 1.14; 22 trials, 1791 babies), with calcium channel blockers (aRR 0.90, 95% CI 0.52 to 1.57; nine trials, 700 babies), or with beta blockers (aRR: 1.23, 95% CI 0.81 to 1.88; 19 trials, 1652 babies); nor in the risk for small-for-gestational age in the comparison with methyldopa (aRR 0.79, 95% CI 0.52 to 1.20; seven trials, 597 babies), with calcium channel blockers (aRR 1.05, 95% CI 0.64 to 1.73; four trials, 200 babies), or with beta blockers (average RR 1.13, 95% CI 0.80 to 1.60; 7 trials, 680 babies). No evidence of an overall difference among groups in the risk of preterm birth (less than 37 weeks) was found in the comparison with methyldopa (aRR: 0.91; 95% CI 0.68 to 1.22; 11 trials, 835 women), with calcium channel blockers (aRR 0.85, 95% CI 0.59 to 1.23; six trials, 330 women), or with beta blockers (aRR 1.22, 95% CI 0.90 to 1.66; 9 trials, 806 women).

SECONDARY OUTCOMES

There were no cases of maternal death andeclampsia. There is no evidence of a difference in the risk of severe pre-eclampsia, changed/stopped drug due to maternal side-effects, elective delivery, admission to neonatal or intensive care nursery when other antihypertensive drugs are compared with methyldopa, calcium channel blockers or beta blockers. Impaired long-term growth and development in infancy and childhood was not reported for these comparisons.

AUTHORS' CONCLUSIONS

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy reduces the risk of severe hypertension. The effect on other clinically important outcomes remains unclear. If antihypertensive drugs are used, beta blockers and calcium channel blockers appear to be more effective than the alternatives for preventing severe hypertension. High-quality large sample-sized randomised controlled trials are required in order to provide reliable estimates of the benefits and adverse effects of antihypertensive treatment for mild to moderate hypertension for both mother and baby, as well as costs to the health services, women and their families.

Inadequate safety reporting in pre-eclampsia trials: a systematic evaluation

BACKGROUND

Randomised trials and their syntheses in meta-analyses offer a unique opportunity to assess the frequency and severity of adverse reactions.

OBJECTIVE

To assess safety reporting in pre-eclampsia trials.

SEARCH STRATEGY

Systematic search using bibliographic databases, including Cochrane Central Register of Controlled Trials, Embase, and MEDLINE, from inception to August 2017.

SELECTION CRITERIA

Randomised trials evaluating anticonvulsant or antihypertensive medication for pre-eclampsia.

DATA COLLECTION AND ANALYSIS

Descriptive statistics appraising the adequacy of adverse reaction and toxicity reporting.

MAIN RESULTS

We included 60 randomised trials. Six trials (10%) were registered with the International Clinical Trials Registry Platform, two registry records referred to adverse reactions, stating 'safety and toleration' and 'possible side effects' would be collected. Twenty-six trials (43%) stated the frequency of withdrawals within each study arm, and five trials (8%) adequately reported these withdrawals. Adverse reactions were inconsistently reported across eligible trials: 24 (40%) reported no serious adverse reactions and 36 (60%) reported no mild adverse reactions. The methods of definition or measurement of adverse reactions were infrequently reported within published trial reports.

CONCLUSIONS

Pre-eclampsia trials regularly omit critical information related to safety. Despite the paucity of reporting, randomised trials collect an enormous amount of safety data. Developing and implementing a minimum data set could help to improve safety reporting, permitting a more balanced assessment of interventions by considering the trade-off between the benefits and harms.

FUNDING

National Institute for Health Research (DRF-2014-07-051), UK; Maternity Forum, Royal Society of Medicine, UK.

TWEETABLE ABSTRACT

Developing @coreoutcomes could help to improve safety reporting in #preeclampsia trials. @NIHR_DC.

Direct Vasodilators and Sympatholytic Agents

Direct vasodilators and sympatholytic agents were some of the first antihypertensive medications discovered and utilized in the past century. However, side effect profiles and the advent of newer antihypertensive drug classes have reduced the use of these agents in recent decades. Outcome data and large randomized trials supporting the efficacy of these medications are limited; however, in general the blood pressure-lowering effect of these agents has repeatedly been shown to be comparable to other more contemporary drug classes. Nevertheless, a landmark hypertension trial found a negative outcome with a doxazosin-based regimen compared to a chlorthalidone-based regimen, leading to the removal of α-1 adrenergic receptor blockers as first-line monotherapy from the hypertension guidelines. In contemporary practice, direct vasodilators and sympatholytic agents, particularly hydralazine and clonidine, are often utilized in refractory hypertension. Hydralazine and minoxidil may also be useful alternatives for patients with renal dysfunction, and both hydralazine and methyldopa are considered first line for the treatment of hypertension in pregnancy. Hydralazine has also found widespread use for the treatment of systolic heart failure in combination with isosorbide dinitrate (ISDN). The data to support use of this combination in African Americans with heart failure are particularly robust. Hydralazine with ISDN may also serve as an alternative for patients with an intolerance to angiotensin antagonists. Given these niche indications, vasodilators and sympatholytics are still useful in clinical practice; therefore, it is prudent to understand the existing data regarding efficacy and the safe use of these medications.

Use and impact of cardiac medication during pregnancy

ABSTRACT 

Cardiovascular disease is the most encountered cause of maternal death during pregnancy in the western world and an increase in maternal mortality due to cardiac causes has been observed. More women with congenital or acquired heart disease have the desire to become pregnant. Pregnancy is known to impose a major hemodynamic burden and also has impacts on the coagulation system. The risk of developing complications is clearly increased as compared with the normal population. For optimal management, it is crucial to have information on the effects of cardiac medications on the fetus. The focus of this article is to discuss the management of cardiac disease in pregnancy, as well as the known safety of cardiac medications for the mother and/or fetus.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild to moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve the outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 April 2013) and reference lists of retrieved studies.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy defined, whenever possible, as systolic blood pressure 140 to 169 mmHg and diastolic blood pressure 90 to 109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data.

MAIN RESULTS

Forty-nine trials (4723 women) were included. Twenty-nine trials compared an antihypertensive drug with placebo/no antihypertensive drug (3350 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) (20 trials, 2558 women; risk ratio (RR) 0.49; 95% confidence interval (CI) 0.40 to 0.60; risk difference (RD) -0.10 (-0.13 to -0.07); number needed to treat to harm (NNTH) 10 (8 to 13)) but little evidence of a difference in the risk of pre-eclampsia (23 trials, 2851 women; RR 0.93; 95% CI 0.80 to 1.08). Similarly, there is no clear effect on the risk of the baby dying (27 trials, 3230 women; RR 0.71; 95% CI 0.49 to 1.02), preterm birth (15 trials, 2141 women; RR 0.96; 95% CI 0.85 to 1.10), or small-for-gestational-age babies (20 trials, 2586 women; RR 0.97; 95% CI 0.80 to 1.17). There were no clear differences in any other outcomes.Twenty-two trials (1723 women) compared one antihypertensive drug with another. Alternative drugs seem better than methyldopa for reducing the risk of severe hypertension (11 trials, 638 women; RR (random-effects) 0.54; 95% CI 0.30 to 0.95; RD -0.11 (-0.20 to -0.02); NNTH 7 (5 to 69)). There is also a reduction in the overall risk of developing proteinuria/pre-eclampsia when beta blockers and calcium channel blockers considered together are compared with methyldopa (11 trials, 997 women; RR 0.73; 95% CI 0.54 to 0.99). However, the effect on both severe hypertension and proteinuria is not seen in the individual drugs. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

AUTHORS' CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild to moderate hypertension during pregnancy is worthwhile.

When one drug affects 2 patients: a review of medication for the management of nonlabor-related pain, sedation, infection, and hypertension in the hospitalized pregnant patient

One of the most difficult challenges health care providers encounter is drug selection for pregnant patients. Drug selection can be complex as efficacy and maternal side effects must be weighed against potential risk to the embryo or fetus. Verification of an individual drug's fetal safety is limited as most evidence is deduced from epidemiologic, prospective cohort, or case-control studies. Medication selection for the pregnant inpatient is a particularly complex task as the illnesses and conditions that require hospitalization mandate different medications, and the risk versus benefit ratio can vary significantly compared to the outpatient setting. Some degree of acute pain is not uncommon among inpatients. Acetaminophen is generally considered the drug of choice in pregnancy for mild to moderate acute pain, while most opioids are thought to be safe for short-term use to manage moderate to severe pain. Providing sedation is particularly challenging as the few options available for the general population are further limited by either known increased risk of congenital malformations or very limited human pregnancy data. Propofol is the only agent recommended for continuous sedation, which has a Food and Drug Administration classification as a pregnancy category B medication. Treatment of infections in hospitalized patients requires balancing the microbiology profile against the fetal risk. Older antimicrobials proven generally safe include beta-lactams, and those with proven fetal risks include tetracyclines. However, little to no information regarding gestational use is available on the newer antimicrobials that are frequently employed to treat resistant infections more commonly found in the inpatient setting. Management of maternal blood pressure is based on the severity of blood pressure elevations and not the hypertensive classification. Agents generally considered safe to use in hypertensive pregnant patients include methyldopa, labetolol, and hydralazine, while angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, hydrochlorothiazide, and atenolol should be avoided.

Do Commonly Used Oral Antihypertensives Alter Fetal or Neonatal Heart Rate Characteristics? A Systematic Review

OBJECTIVE

To examine fetal (FHR) and neonatal heart rate patterns following use of common oral antihypertensives in pregnancy.

METHODS

A systematic review of randomized controlled trials (RCTs), observational studies (N >/= 6 women), and animal studies. Data were abstracted (two reviewers) to determine relative risk (RR) (or risk difference (RD) for low event rates) and 95% CI.

RESULTS

Eighteen RCTs (1858 women), one controlled observational study (N = 22), and seven case series (N = 117) were reviewed. Most hypertension was pregnancy-induced (N = 14 studies). The FHR was assessed by cardiotocogram (CTG) (N = 17 studies (visual interpretation); 1 study (computerized CTG), or umbilical artery velocimetry (N = 4). Four studies examined neonatal heart rate. In placebo-controlled RCTs (N = 192 women), adverse FHR effects did not differ between groups [9/101 (drugs) vs. 7/91 (placebo); RD 0.02, 95% CI (- 0.06, 0.11); chi2 = 1.02]. In six drug vs. drug RCTs (295 women), adverse FHR effects did not differ between groups [29/144 (methyldopa) vs. 42/151 (other drugs); RR 0.72, 95% CI (0.49, 1.07); chi2 = 0.69]. In one labetalol vs. placebo trial, neonatal bradycardia did not differ between groups [4/70 (labetalol) vs. 4/74 (placebo); OR 1.06, 95% CI (0.26, 4.39)], while in three drug vs. drug RCTs, neonatal bradycardia was not observed (0/24 vs. 0/26).

CONCLUSIONS

Available data are inadequate to conclude whether oral methyldopa, labetalol, nifedipine, or hydralazine adversely affect fetal or neonatal heart rate and pattern. Until definitive data are available, FHR changes cannot be reliably attributed to drug effect, but may be due to progression of the underlying maternal or placental disease.

Use of antihypertensive drugs during pregnancy and lactation

The decision to treat elevated arterial pressure in pregnancy depends on the risk and benefits imposed on the mother and the fetus. Treatment for mild-to-moderate hypertension during pregnancy may not reduce maternal or fetal risk. Severe hypertension, on the other hand, should be treated to decrease maternal risk. Methyldopa and beta-adrenoceptor antagonists have been used most extensively. In acute severe hypertension, intravenous labetalol or oral nifedipine are reasonable choices.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild to moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2005, Issue 3), MEDLINE (1966 to November 2005), LILACS (1984 to November 2005) and EMBASE (1974 to November 2005).

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy defined, whenever possible, as systolic blood pressure 140 to 169 mmHg and diastolic blood pressure 90 to 109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data.

MAIN RESULTS

Forty-six trials (4282 women) were included. Twenty-eight trials compared an antihypertensive drug with placebo/no antihypertensive drug (3200 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) (19 trials, 2409 women; relative risk (RR) 0.50; 95% confidence interval (CI) 0.41 to 0.61; risk difference (RD) -0.10 (-0.12 to -0.07); number needed to treat (NNT) 10 (8 to 13)) but little evidence of a difference in the risk of pre-eclampsia (22 trials, 2702 women; RR 0.97; 95% CI 0.83 to 1.13). Similarly, there is no clear effect on the risk of the baby dying (26 trials, 3081 women; RR 0.73; 95% CI 0.50 to 1.08), preterm birth (14 trials, 1992 women; RR 1.02; 95 % CI 0.89 to 1.16), or small-for-gestational-age babies (19 trials, 2437 women; RR 1.04; 95 % CI 0.84 to 1.27). There were no clear differences in any other outcomes. Nineteen trials (1282 women) compared one antihypertensive drug with another. Beta blockers seem better than methyldopa for reducing the risk of severe hypertension (10 trials, 539 women, RR 0.75 (95 % CI 0.59 to 0.94); RD -0.08 (-0.14 to 0.02); NNT 12 (6 to 275)). There is no clear difference between any of the alternative drugs in the risk of developing proteinuria/pre-eclampsia. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

AUTHORS' CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild to moderate hypertension during pregnancy is worthwhile.

Arterial stiffness in preeclamptic and chronic hypertensive pregnancies

OBJECTIVE

To assess arterial stiffness in pregnancies complicated by hypertensive disorders: preeclampsia and chronic hypertension.

STUDY DESIGN

Twenty preeclamptic and 18 chronic hypertensive parturients were studied. The reference data were obtained from 29 healthy pregnant women and 29 non-pregnant women. Systolic blood pressure (SAP), diastolic blood pressure (DAP), mean arterial pressure (MAP) and pulse pressure (PP) were measured. Stroke index (SI), heart rate (HR), cardiac index (CI), systemic vascular resistance index (SVRI) and pulse wave velocity (PWV) were derived by whole-body impedance cardiography. Arterial compliance was defined as the SI to PP ratio (SI/PP).

RESULTS

Significantly higher PP and PWV and lower SI/PP were observed in preeclamptic compared to uncomplicated pregnancies. Preeclamptic pregnancies also differed from chronic hypertensive pregnancies by higher PP and lower SI/PP. Women with chronic hypertension had significantly higher PWV than the control group, but PP and SI/PP were not different. In both hypertensive groups SVRI was exceptionally high.

CONCLUSIONS

Besides the vasoconstriction of smaller peripheral arteries, our finding of increased arterial stiffness in preeclamptic pregnancies suggests that also larger arteries with altered viscoelastic properties are involved in the aberrant hemodynamics of preeclampsia. Compared to preeclamptic subjects, women with chronic hypertension shared a common feature of high systemic vascular resistance, but changes in arterial stiffness were less than in preeclampsia.

Hypertension in pregnancy

Hypertension in pregnancy contributes significantly to both maternal and neonatal morbidity and mortality. Among different forms of pregnancy-associated hypertension, preeclampsia-eclampsia has the highest impact on morbidity and mortality. Chronic hypertension may result in preterm and small for gestational age infants, even when it is mild-to-moderate. Chronic hypertension is a risk factor for superimposed preeclampsia and results in higher rates of adverse outcome. Preeclampsia is a multisystemic disease that is thought to be initiated by abnormalities in placental perfusion and endothelial dysfunction, ultimately resulting in multiorgan failure. Preeclampsia is more common in women of minority ethnicity who are socioeconomically disadvantaged. Pharmacologic therapy for hypertensive disorders in pregnancy is limited by concerns regarding the safety of both mother and fetus. Although treatment of severe hypertension is not debated, there is no consensus on the rationale for pharmacologic therapy of mild-to-moderate hypertension in pregnancy.

Cardiovascular Pharmacotherapeutic Considerations During Pregnancy and Lactation

Table 2 summarizes the recommendations regarding the use of cardiovascular drugs during pregnancy and lactation.

Pharmacologic treatment of hypertensive disorders during pregnancy

Pregnancy complicated by hypertension is a common problem faced by clinicians. It can lead to substantial maternal and/or fetal/neonatal morbidity and mortality. There are a variety of medications that can be used during pregnancy either for treatment of significant chronic hypertension or in cases of acute severe hypertension. Most antihypertensive drugs have been shown to be safe for use in pregnancy. A variety of medications are available to treat more severe hypertension, although the use of pharmacologic therapy to treat mild chronic hypertension during pregnancy has not been supported in the literature. The data are more limited concerning drugs that would be used in the event of hypertensive emergencies or in an intensive care setting; however, in such a situation, maternal health and life become paramount and, despite lack of good studies, appropriate treatment should be rendered.

Antihypertensive drug therapy for mild to moderate hypertension during pregnancy

BACKGROUND

Mild-moderate hypertension during pregnancy is common. Antihypertensive drugs are often used in the belief that lowering blood pressure will prevent progression to more severe disease, and thereby improve outcome.

OBJECTIVES

To assess the effects of antihypertensive drug treatments for women with mild to moderate hypertension during pregnancy.

SEARCH STRATEGY

Relevant trials were identified in the register of trials maintained by the Cochrane Pregnancy and Childbirth Group. In addition, the Cochrane Controlled Trial Register, MEDLINE, and EMBASE were searched. Date of last search: October 2000.

SELECTION CRITERIA

All randomised trials evaluating any antihypertensive drug treatment for mild to moderate hypertension during pregnancy, defined whenever possible as systolic blood pressure 140-169 mmHg and diastolic blood pressure 90-109 mmHg. Comparisons were of one or more antihypertensive drug(s) with placebo, with no antihypertensive drug, or with another antihypertensive drug, and where treatment was planned to continue for at least seven days.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by two reviewers.

MAIN RESULTS

Overall, this review includes 40 studies (3797 women), 24 of which compared an antihypertensive drug with placebo/no antihypertensive drug (2815 women). There is a halving in the risk of developing severe hypertension associated with the use of antihypertensive drug(s) [17 trials, 2155 women; relative risk (RR) 0.52 (95% confidence interval (CI) 0.41 to 0.64); risk difference (RD) -0.09 (-0.12 to -0.06); number needed to treat (NNT) 12 (9 to 17)] but little evidence of a difference in the risk of pre-eclampsia [19 trials, 2402 women; RR 0.99 (0.84 to 1.18)]. Similarly, there is no clear effect on the risk of the baby dying [23 trials, 2727 women; RR 0.71(0.46 to 1.09)], preterm birth [12 trials, 1738 women; RR 0.98 (0.85 to 1.13)], or small for gestational age babies [17 trials, 2159 women; RR 1.13 (0.91 to 1.42)]. There were no clear differences in any other outcomes. Seventeen trials (1182 women) compared one antihypertensive drug with another. There is no clear difference between any of these drugs in the risk of developing severe hypertension, and proteinuria/pre-eclampsia. Other antihypertensive agents seem better than methyldopa for reducing the risk of the baby dying [14 trials, 1010 subjects, RR 0.49 (0.24 to 0.99); RD -0.02 (-0.04 to 0.00); NNT 45 (22 to 1341)]. Other outcomes were only reported by a small proportion of studies, and there were no clear differences.

REVIEWER'S CONCLUSIONS

It remains unclear whether antihypertensive drug therapy for mild-moderate hypertension during pregnancy is worthwhile.

Management of hypertension in pregnancy

Hypertension is an important cause of both maternal and fetal morbidity and mortality in pregnant women. There are still no definitive guidelines as to when and how patients should be treated, but it is important that appropriate treatment is initiated early in patients at highest risk and they are closely monitored. Hypertension in pregnancy can be a difficult condition to diagnose and treat because of the numerous and differing classification systems that have been used in the past. One classification system, which accounts for the multisystem involvement which can occur in pre-eclampsia and eclampsia, divides hypertension in pregnancy into 3 main groups: pre-eclampsia, gestational hypertension and chronic hypertension. Little benefit to the fetus has been shown from treating gestational and chronic hypertension, but studies in this area have been small and would not have had the power to show a difference in outcome between treated and untreated groups. However, the reduction in morbidity and mortality in the treatment of pre-eclampsia is significant. Therefore, all pregnancies complicated by hypertension require monitoring to detect the possible onset of superimposed pre-eclampsia/eclampsia. Institutions should have a management strategy for those mothers with severe hypertension including a multidisciplinary approach, where the patient is to be monitored and which antihypertensive agents are to be used. It should not be forgotten that the definitive treatment for severe hypertension is delivery of the fetus despite risks to fetal morbidity and mortality. This will reduce blood pressure, but hypertension per se may still persist post partum requiring short term therapy.

Fall in mean arterial pressure and fetal growth restriction in pregnancy hypertension: a meta-analysis

BACKGROUND

We investigated the relation between fetoplacental growth and the use of oral antihypertensive medication to treat mild-to-moderate pregnancy hypertension.

METHODS

The study design was a metaregression analysis of published data from randomised controlled trials. Data from a paper that was regarded as an extreme statistical outliner were excluded from primary analyses. The change in (group) mean arterial pressure (MAP) from enrolment to delivery was compared with indicators of fetoplacental growth.

FINDINGS

Greater mean difference in MAP with antihypertensive therapy was associated with the birth of a higher proportion of small-for-gestational-age (SGA) infants (slope: 0.09 [SD 0.03], r2=0.48, p=0.006, 14 trials) and lower mean birthweight significant after exclusion of data from another paper regarded as an extreme statistical outliner (slope: -14.49 [6.98] r=0.16, p=0.049, 27). No relation with mean placental weight was seen (slope -2.01 [1.62], r2=0.15, p=0.25, 11 trials).

INTERPRETATION

Treatment-induced falls in maternal blood pressure may adversely affect fetal growth. Given the small maternal benefits that are likely to be derived from therapy, new data are urgently needed to elucidate the relative maternal and fetal benefits and risks of oral antihypertensive drug treatment of mild-to-moderate pregnancy hypertension.

Risks and benefits of beta-receptor blockers for pregnancy hypertension: overview of the randomized trials

OBJECTIVE

Examine the benefits/risks of beta-blockers for pregnancy hypertension.

STUDY DESIGN

Meta-analysis of relevant trials identified by comprehensive literature review (1966-97).

RESULTS

Included were 30 trials for pregnancy hypertension, and four others for perinatal outcomes only. For mild chronic hypertension treated throughout pregnancy (n=2 trials), oral beta-blockers (compared with no therapy) were associated with an inconsistent increase in small for gestational age (SGA) infants (OR 2.46 [1.02, 5.92]). For mild-moderate 'late-onset' pregnancy hypertension (i.e. either chronic treated only late in pregnancy, or pregnancy-induced) (n=8 trials), oral beta-blockers (compared with no therapy) were associated with a decrease in severe hypertension (OR 0.27 [0.16, 0.451), borderline decrease in development of proteinuria (OR 0.69 [0.48, 1.02]), decrease in RDS (OR 0.33 [0.13, 0.85]), but a borderline increase in SGA infants (OR 1.47 [0.96, 2.26]). Beta-blockers were equivalent to other agents (n=15 trials). For severe 'late-onset' pregnancy hypertension (n=5 trials), i.v. labetalol produced less maternal hypotension (OR 0.13 [0.03, 0.71]) and fewer cesareans (OR 0.23 [0.13, 0.63]) than i.v. hydralazine/diazoxide.

CONCLUSIONS

It is not clear that the benefits outweigh the risks when beta-blockers are used to treat mild to moderate chronic or pregnancy-induced hypertension, given the unknown overall effect on perinatal outcomes. For severe 'late-onset' pregnancy hypertension, i.v. labetalol is safer than i.v. hydralazine or diazoxide.

Oral beta-blockers for mild to moderate hypertension during pregnancy

BACKGROUND

Hypertension is a common complication of pregnancy. Antihypertensive drugs are widely used in the belief these will improve outcome for both the woman (such as decreasing the risk of stroke or eclampsia) and her baby (such as decreasing the risk of preterm birth and its complications). Beta-blockers are a popular choice of antihypertensive agent during pregnancy; other choices include methyldopa and calcium channel blockers.

OBJECTIVES

The aim of this review is to assess whether oral beta-blockers are overall better than placebo, or no beta-blocker, for women with mild-moderate hypertension during pregnancy, and to assess whether oral beta-blockers have any advantages over other antihypertensive agents for women with mild-moderate hypertension during pregnancy. Both maternal outcomes (e.g., the incidence of severe hypertension) and perinatal outcomes (e.g., mortality) were of interest.

SEARCH STRATEGY

Register of trials maintained by the Cochrane Pregnancy and Childbirth Group, MEDLINE 1966-97, bibliographies of retrieved papers, personal files. Date of last search: June 2000.

SELECTION CRITERIA

Trials comparing beta-blockers with (i) placebo or no therapy, or (ii) other antihypertensive agents, for women with mild-moderate pregnancy hypertension (i.e., blood pressure under 170 mm Hg systolic, or 110 mm Hg diastolic).

DATA COLLECTION AND ANALYSIS

All data were extracted independently by two investigators, who were not blinded to outcome or other trial characteristics. Whenever possible, missing data were obtained by personal communication with authors. Discrepancies were resolved by discussion. The overview was divided into two comparisons: (i) beta-blockers versus placebo or no therapy, and (ii) beta-blockers versus other antihypertensives.

MAIN RESULTS

Twenty-seven trials, involving just under 2400 women, are included in this review. Fourteen trials (1516 women) compared beta-blockers with placebo/no beta blocker. Oral beta-blockers decrease the risk of severe hypertension (relative risk (RR) 0.37, 95% confidence interval (CI) 0.26-0.53) and the need for additional antihypertensive drugs (RR 0.44, 95% CI 0.31-0.62). There are insufficient data for any conclusions about the effect on perinatal mortality or preterm delivery. Beta-blockers seem to be associated with an increase in small for gestational age infants (RR 1.34, 95% CI 1.01-1.79). Maternal hospital admission may be decreased, neonatal bradycardia increased and respiratory distress syndrome decreased, but these outcomes are only reported in a very small proportion of trials. Eleven trials (787 women) compared beta-blockers with methyldopa. Beta-blockers appear to be no more effective and probably equally as safe (from maternal and perinatal perspectives) as methyldopa. Single small trials have compared beta-blockers with hydralazine and with nicardipine. It is unusual for women to change drugs due to side effects.

REVIEWER'S CONCLUSIONS

The improvement in control of maternal blood pressure with use of beta-blockers would be worthwhile only if it were reflected in other more substantive benefits for the mother and/or baby, and none have yet been clearly demonstrated. The effect of beta-blockers on perinatal outcome is uncertain, given that the worrying trend to an increase in small for gestational age infants is partly dependent on one small outlying trial. Large, randomised controlled trials are needed to determine whether antihypertensive therapy in general (rather than beta-blocker therapy specifically) results in benefits that outweigh the risks for treatment of mild-moderate pregnancy hypertension. If so, then it would be appropriate to look at which antihypertensive is best. Beta-blockers would remain a candidate class of agents.

Clinical pharmacokinetics of vasodilators. Part II

Stimulating cardiac beta 1-adrenoceptors with oxyfedrine causes dilatation of coronary vessels and positive inotropic effects on the myocardium. beta 1-adrenergic agonists increase coronary blood flow in nonstenotic and stenotic vessels. The main indication for the use of the phosphodiesterase inhibitors pamrinone, mirinone, enoximone and piroximone is acute treatment of severe congestive heart failure. Theophylline is indicated for the treatment of asthma, chronic obstructive pulmonary disease, apnea in preterm infants ans sleep apnea syndrome. Severe arterial occlusive disease associated with atherosclerosis can be beneficially affected by elcosanoids. These drugs must be administered parenterally and have a half-life of only a few minutes. Sublingual or buccal preparations of nitrates are the only prompt method (within 1 or 2 min) of terminating anginal pain, except for biting nifedipine capsules. The short half-life (about 2.5 min) of nitroglycerin (glyceryl trinitrate) makes long term therapy impossible. Tolerance is a problem encountered with longer-acting nitric oxide donors. Knowledge of the pharmacokinetic properties of vasodilating drugs can prevent a too sudden and severe blood pressure decrease in patients with chronic hypertension. In considering the administration of a second dose, or another drug, the time necessary for the initially administered drug to reach maximal efficacy should be taken into account. In hypertensive emergencies urapidil, sodium nitroprusside, nitroglycerin, hydralazine and phentolamine are the drugs of choice, with the addition of beta-blockers during catecholamine crisis or dissecting aortic aneurysm. Childhood hypertension is most often treated with angiotensin-converting enzyme (ACE) inhibitors or calcium antagonists, primarily nifedipine. Because of the teratogenic risk involved with ACE inhibitors, extreme caution must be exercised when prescribing for adolescent females. The propagation of health benefits to breast-fed infants, combined with more women delaying pregnancy until their fourth decade, has entailed an increase in the need for hypertension management during lactation. Low dose hydrochlorothiazide, propranolol, nifedipine and enalapril or captopril do not pose enough of a risk of preclude breastfeeding in this group. The most frequently used antihypertensive agents during pregnancy are methyldopa, labetalol and calcium channel antagonists. Methyldopa and beta-blockers are the drugs of choice for treating mild to moderate hypertension. Prazosin and hydralazine are used to treat moderate to severe hypertension and hydralazine, urapidil or labetalol are used to treat hypertensive emergencies. The use of overly aggressive antihypertensive therapy during pregnancy should be avoided so that adequate uteroplacental blood flow is maintained. Methyldopa is the only drug accepted for use during the first trimester of pregnancy.