Comparison of antihypertensive efficacy and perinatal safety of labetalol and methyldopa in the treatment of hypertension in pregnancy: a randomized controlled trial

Fetoplacental vascular effects of maternal adrenergic antihypertensive and cardioprotective medications in pregnancy

Maternal cardiovascular diseases, including hypertension and cardiac conditions, are associated with poor fetal outcomes. A range of adrenergic antihypertensive and cardioprotective medications are often prescribed to pregnant women to reduce major maternal complications during pregnancy. Although these treatments are not considered teratogenic, they may have detrimental effects on fetal growth and development, as they cross the fetoplacental barrier, and may contribute to placental vascular dysregulation. Medication risk assessment sheets do not include specific advice to clinicians and women regarding the safety of these therapies for use in pregnancy and the potential off-target effects of adrenergic medications on fetal growth have not been rigorously conducted. Little is known of their effects on the fetoplacental vasculature. There is also a dearth of knowledge on adrenergic receptor activation and signalling within the endothelium and vascular smooth muscle cells of the human placenta, a vital organ in the maintenance of adequate blood flow to satisfy fetal growth and development. The fetoplacental circulation, absent of sympathetic innervation, and unique in its reliance on endocrine, paracrine and autocrine influence in the regulation of vascular tone, appears vulnerable to dysregulation by adrenergic antihypertensive and cardioprotective medications compared with the adult peripheral circulation. This semi-systematic review focuses on fetoplacental vascular expression of adrenergic receptors, associated cell signalling mechanisms and predictive consequences of receptor activation/deactivation by antihypertensive and cardioprotective medications.

Hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy (HDP) are one of the most commonly occurring complications of pregnancy and include chronic hypertension, gestational hypertension, and pre-eclampsia. New developments in early pregnancy screening to identify women at high risk for pre-eclampsia combined with targeted aspirin prophylaxis could greatly reduce the number of affected pregnancies. Furthermore, recent advances in the diagnosis of pre-eclampsia, such as placental growth factor based testing, have been shown to improve the identification of those pregnancies at highest risk of severe complications. Evidence from trials has refined the target blood pressure and timing of delivery to manage chronic hypertension and pre-eclampsia with non-severe features, respectively. Importantly, a wealth of epidemiological data now links HDP to future cardiovascular disease and diabetes decades after an affected pregnancy. This review discusses the current guidelines and research data on the prevention, diagnosis, management, and postnatal follow-up of HDP. It also discusses the gap in knowledge regarding the long term risks for cardiovascular disease following HDP and illustrates the importance of improving adherence to postnatal guidelines to monitor hypertension and the need for more research focused on primary prevention of future cardiovascular disease in women identified as being at high risk because of HDP.

Management of hypertension in pregnancy

Hypertensive diseases of pregnancy remain a leading cause of maternal and neonatal morbidity and mortality. Therefore, we sought to review the management of these conditions in pregnancy. In this review we discuss the most updated definitions, different antihypertensives, delivery recommendations and overall goals of management, including their effects on uteroplacental perfusion. We also highlight different medical situations where one antihypertensive may be preferable over others.

Preeclampsia beyond pregnancy: long-term consequences for mother and child

Preeclampsia is defined as new-onset hypertension after the 20th wk of gestation along with evidence of maternal organ failure. Rates of preeclampsia have steadily increased over the past 30 yr, affecting ∼4% of pregnancies in the United States and causing a high economic burden (22, 69). The pathogenesis is multifactorial, with acknowledged contributions by placental, vascular, renal, and immunological dysfunction. Treatment is limited, commonly using symptomatic management and/or early delivery of the fetus (6). Along with significant peripartum morbidity and mortality, current research continues to demonstrate that the consequences of preeclampsia extend far beyond preterm delivery. It has lasting effects for both mother and child, resulting in increased susceptibility to hypertension and chronic kidney disease (45, 54, 115, 116), yielding lifelong risk to both individuals. This review discusses recent guideline updates and recommendations along with current research on these long-term consequences of preeclampsia.

Hypertension in pregnancy: Pathophysiology and treatment

Hypertensive disorders of pregnancy, an umbrella term that includes preexisting and gestational hypertension, preeclampsia, and eclampsia, complicate up to 10% of pregnancies and represent a significant cause of maternal and perinatal morbidity and mortality. Despite the differences in guidelines, there appears to be consensus that severe hypertension and non-severe hypertension with evidence of end-organ damage need to be controlled; yet the ideal target ranges below 160/110 mmHg remain a source of debate. This review outlines the definition, pathophysiology, goals of therapy, and treatment agents used in hypertensive disorders of pregnancy.

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.

In-utero exposure to antihypertensive medication and neonatal and child health outcomes: a systematic review

BACKGROUND

Although medication is generally avoided wherever possible during pregnancy, pharmacotherapy is required for the treatment of pregnancy associated hypertension, which remains a leading cause of maternal and fetal morbidity and mortality. The long-term effects to the child of in-utero exposure to antihypertensive agents remains largely unknown.

OBJECTIVE

The aim of this study was to systematically review published studies on adverse outcomes to the child associated with in-utero exposure to antihypertensive medications.

METHODS

OVID, Scopus, EBSCO Collections, the Cochrane Library, and Web of Science databases were searched for relevant publications published between January 1950 and October 2016 and a total of 688 potentially eligible studies were identified.

RESULTS

Following review, 47 primary studies were eligible for inclusion. The Critical Appraisal Skills Programme checklist was used to assess study quality. Five studies were of excellent quality; the remainder were either mediocre or poor. Increased risk of low birth weight, low size for gestational age, preterm birth, and congenital defects following in-utero exposure to all antihypertensive agents were identified. Two studies reported an increased risk of attention deficit hyperactivity disorder following exposure to labetalol, and an increased risk of sleep disorders following exposure to methyldopa and clonidine.

CONCLUSION

The current systematic review demonstrates a paucity of relevant published high-quality studies. A small number of studies suggest possible increased risk of adverse child health outcomes; however, most published studies have methodological weaknesses and/or lacked statistical power thus preventing any firm conclusions being drawn.

Impact of Antihypertensive Treatment on Maternal and Perinatal Outcomes in Pregnancy Complicated by Chronic Hypertension: A Systematic Review and Meta-Analysis

BACKGROUND

Chronic hypertension complicates around 3% of all pregnancies. There is evidence that treating severe hypertension reduces maternal morbidity. This study aimed to systematically review randomized controlled trials of antihypertensive agents treating chronic hypertension in pregnancy to determine the effect of this intervention.

METHODS AND RESULTS

Medline (via OVID), Embase (via OVID) and the Cochrane Trials Register were searched from their earliest entries until November 30, 2016. All randomized controlled trials evaluating antihypertensive treatments for chronic hypertension in pregnancy were included. Data were extracted and analyzed in Stata (version 14.1). Fifteen randomized controlled trials (1166 women) were identified for meta-analysis. A clinically important reduction in the incidence of severe hypertension was seen with antihypertensive treatment versus no antihypertensive treatment/placebo (5 studies, 446 women; risk ratio 0.33, 95%CI 0.19-0.56; I2 0.0%). There was no difference in the incidence of superimposed pre-eclampsia (7 studies, 727 women; risk ratio 0.74, 95%CI 0.49-1.11; I2 28.1%), stillbirth/neonatal death (4 studies, 667 women; risk ratio 0.37, 95%CI 0.11-1.26; I2 0.0%), birth weight (7 studies, 802 women; weighted mean difference -60 g, 95%CI -200 to 80 g; I2 0.0%), or small for gestational age (4 studies, 369 women; risk ratio 1.01, 95%CI 0.53-1.94; I2 0.0%) with antihypertensive treatment versus no treatment/placebo.

CONCLUSIONS

Antihypertensive treatment reduces the risk of severe hypertension in pregnant women with chronic hypertension. A considerable paucity of data exists to guide choice of antihypertensive agent. Adequately powered head-to-head randomized controlled trials of commonly used antihypertensive agents are required to inform prescribing.

Neonatal haemodynamic effects following foetal exposure to labetalol in hypertensive disorders of pregnancy

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) affect foetal outcome. Labetalol is frequently used to lower maternal blood pressure and prolong pregnancy. Conflicting evidence exists for specific neonatal side effects described after maternal labetalol treatment. Our aim was to investigate neonatal effects of foetal exposure to labetalol on cerebral oxygenation and extraction.

METHODS

In a prospective observational study, clinical characteristics, vital parameters and cerebral oxygen delivery and extraction were collected during the first 24 h of life in labetalol-exposed preterm neonates and compared with two control groups.

RESULTS

Twenty-two infants with a mean gestational age of 28.9 weeks, born from labetalol-treated mothers with HDP were included and matched with 22 infants with non-labetalol-treated mothers with HDP and 22 infants without maternal HDP. No significant differences between groups were found neither in heart rate, blood pressure and inotropic support, nor in mean regional cerebral oxygen saturation and fractional tissue oxygen extraction.

CONCLUSION

Foetal labetalol exposure associated effects on preterm heart rate, blood pressure, cerebral oxygenation and extraction are not demonstrated. Maternal disease severity seems to play a more important role in neonatal cerebral haemodynamics. Maternal labetalol treatment has no clinically important short term side effects in the preterm neonate.

Labetalol for hypertension in pregnancy

INTRODUCTION

Labetalol is one of the most commonly used antihypertensive medications for the treatment of hypertension during pregnancy, an increasingly common and leading cause of maternal mortality and morbidity worldwide.

AREAS COVERED

The literature reviewed included the 2014 Canadian national pregnancy hypertension guideline and its references. The additional published literature was retrieved through searches of Medline, CINAHL, and The Cochrane Library using appropriate controlled vocabulary (e.g., pregnancy, hypertension, pre-eclampsia, pregnancy toxemias) and key words (e.g., diagnosis, evaluation, classification, prediction, prevention, prognosis, treatment, and postpartum follow-up).Results were restricted to systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies published in French or English, Jan-Mar/14. The unpublished literature was identified by searching websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. We evaluated the impact of interventions on substantive clinical outcomes for mothers and babies.

EXPERT OPINION

Labetalol is a reasonable choice for treatment of severe or non-severe hypertension in pregnancy. However, we should continue our search for other therapeutic options.

Do labetalol and methyldopa have different effects on pregnancy outcome? Analysis of data from the Control of Hypertension In Pregnancy Study (CHIPS) trial

OBJECTIVE

To compare pregnancy outcomes, accounting for allocated group, between methyldopa-treated and labetalol-treated women in the CHIPS Trial (ISRCTN 71416914) of 'less tight' versus 'tight' control of pregnancy hypertension.

DESIGN

Secondary analysis of CHIPS Trial cohort.

SETTING

International randomised controlled trial (94 sites, 15 countries).

POPULATION OR SAMPLE

Of 987 CHIPS recruits, 481/566 (85.0%) women treated with antihypertensive therapy at randomisation. Of 981 (99.4%) women followed to delivery, 656/745 (88.1%) treated postrandomisation.

METHODS

Logistic regression to compare outcomes among women who took methyldopa or labetalol, adjusted for the influence of baseline factors.

MAIN OUTCOME MEASURES

CHIPS primary (perinatal loss or high level neonatal care for >48 hours) and secondary (serious maternal complications) outcomes, birthweight <10th centile, severe maternal hypertension, pre-eclampsia and delivery at <34 or <37 weeks.

RESULTS

Methyldopa and labetalol were used commonly at randomisation (243/987, 24.6% and 238/987, 24.6%, respectively) and post-randomisation (224/981, 22.8% and 433/981, 44.1%, respectively). Following adjusted analyses, methyldopa (versus labetalol) at randomisation was associated with fewer babies with birthweight <10th centile [adjusted odds ratio (aOR) 0.48; 95% CI 0.20-0.87]. Methyldopa (versus labetalol) postrandomisation was associated with fewer CHIPS primary outcomes (aOR 0.64; 95% CI 0.40-1.00), birthweight <10th centile (aOR 0.54; 95% CI 0.32-0.92), severe hypertension (aOR 0.51; 95% CI 0.31-0.83), pre-eclampsia (aOR 0.55; 95% CI 0.36-0.85), and delivery at <34 weeks (aOR 0.53; 95% CI 0.29-0.96) or <37 weeks (aOR 0.55; 95% CI 0.35-0.85).

CONCLUSION

These nonrandomised comparisons are subject to residual confounding, but women treated with methyldopa (versus labetalol), particularly those with pre-existing hypertension, may have had better outcomes.

TWEETABLE ABSTRACT

There was no evidence that women treated with methyldopa versus labetalol had worse outcomes.

Pregnancy in end-stage renal disease patients on dialysis: how to achieve a successful delivery

Pregnancy in women with chronic kidney disease has always been considered as a challenging event both for the mother and the fetus. Over the years, several improvements have been achieved in the outcome of pregnant chronic renal patients with increasing rates of successful deliveries. To date, evidence suggests that the stage of renal failure is the main predictive factor of worsening residual kidney function and complications in pregnant women. Moreover, the possibility of success of the pregnancy depends on adequate depurative and pharmacological strategies in patients with end-stage renal disease. In this paper, we propose a review of the current literature about this topic presenting our experience as well.

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.

Nifedipine versus labetalol in the treatment of hypertensive disorders of pregnancy

PURPOSE

To assess the maternal and fetal outcomes of pregnancies affected by hypertensive disorders treated with nifedipine versus labetalol.

METHODS

A retrospective study in hypertensive patients treated during pregnancy with nifedipine or labetalol was conducted. After the charts review the patients were divided in the four groups: gestational hypertension (113 patients); mild preeclampsia (77 patients); severe preeclampsia (31 patients); HELLP syndrome (21 patients). The pregnancy and neonatal records were analyzed by paired and unpaired t test.

RESULTS

We found that there was an higher rate of intrauterine growth restriction infants among women treated with labetalol compared with those treated with nifedipine (38.8 vs. 15.5 %; p < 0.05), but only in the subgroup of women affected by Gestational Hypertension and Mild Preeclampsia. In this group was also higher the rate of fetal worsening assessed by fetal heart rate tracing (33.3 vs. 14.2 %; p < 0.05). No neonatal malformations and no differences in the rate of adverse side effects were observed.

CONCLUSIONS

Antihypertensive therapy in pregnancy with Labetalol may have the potential to impair fetal behavior in low degrees hypertensive diseases of pregnancy. Optimal care must balance the potentially conflicting risks and benefits to mother and fetus.

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.

Antihypertensive drugs in pregnancy

Blood pressure targets and medications that are safe differ in pregnant women compared with nonpregnant individuals. The principles of treatment for mild, moderate, and severe hypertension in pregnancy, chronic versus gestational versus preeclampsia, and women hypertensive at term versus remote from term are reviewed. The choice of antihypertensive drugs also is discussed; methyldopa, labetalol, and nifedipine, among others, appear safe for use in pregnancy, whereas angiotensin converting enzyme inhibitors and angiotensin receptor blockers should be avoided. The management of increased blood pressure in the postpartum period, and agents to use in lactation, are also discussed.

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.

Antihypertensive therapy during pregnancy

Hypertensive disorders in pregnancy are a leading cause of maternal and perinatal morbidity and mortality. Overall, hypertension complicates approximately 10% of pregnancies. The incidence is higher in patients with predisposing factors including nulliparity, multiple gestation, preexisting hypertension or diabetes, a previous pregnancy complicated by preeclampsia-eclampsia, familial history of preeclampsia, hydrops fetalis and rapidly growing hydatidiform moles.

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.

Pathophysiology and Medical Management of Systemic Hypertension in Pregnancy

Hypertension in pregnancy includes a group of distinct disorders that require special consideration in both prevention and pharmacologic treatment. In recent years, there have been few advances regarding the pathophysiology and prevention of preeclampsia or in the recommendations for first-line drug therapy for its hypertensive complications. Similarly, the recommendations for pharmacologic treatment of women with chronic hypertension antedating pregnancy have changed little primarily because first-line medications have the advantage of having had more extensive research experience. Recent clinical trials have demonstrated the efficacy and safety of various second-line drugs for the hypertensive disorders of pregnancy; whether these therapies can eventually replace the standard recommended medications will require more extensive long-term investigation.

Spectrum of hypertensive emergencies in pregnancy

Hypertension in pregnancy represents a spectrum of clinical entities, including pregnancy-induced hypertension (PIH), preeclampsia, eclampsia, and hemolysis, elevated liver enzyme levels, low platelet count syndrome. Although hypertension is a common denominator in this group of disorders, the pathogenesis, clinical features, and clinical course of these disorders is variable and somewhat distinct. Therapy must be tailored to the clinical entity and the patient. The incidence and prevalence of preeclampsia and eclampsia is decreasing worldwide. This decrease partly may be caused by the improved treatment of PIH and improved obstetrical services.

Fall in mean arterial pressure and fetal growth restriction in pregnancy hypertension: an updated metaregression analysis

OBJECTIVE

To update our previous analysis of randomized controlled trials in pregnancy hypertension, which discerned that greater treatment-induced decreases in maternal mean arterial pressure (MAP) appear to adversely affect fetal growth.

METHODS

We conducted an English-language computer search of MEDLINE, Hypertension in Pregnancy, the relevant Cochrane reviews, and the bibliographies of retrieved papers, review articles, and standard obstetric and toxicology texts. Metaregression analysis was used to compare the change in MAP from enrollment to delivery with birth weight.

RESULTS

Seven new trials with 335 women were added to the 27 trials with 2305 women previously reported. No new trials reported on the frequency of small for gestational age infants. Treatment-induced mean difference in MAP was associated with lower mean birth weight (slope: -17.55 [SD 6.67], r2 = 0.19, Spearman's non-parametric p = 0.031, Pearson's parametric p = 0.013). Therefore, over the range of reported mean differences in MAP, a 10 mm Hg fall in MAP was associated with a 176 g decrease in birth weight, and 19% of the birth weight difference between trials could be explained by differential blood pressure control.

CONCLUSION

These results strengthen the association between blood pressure control and restricted fetal growth, and reinforce the need for new data to elucidate optimal antihypertensive use for mild to moderate pregnancy hypertension.

Chronic hypertension in pregnancy

Pregnant women with chronic hypertension are at risk for maternal and perinatal morbidity. Careful assessment and management of these patients during pregnancy are the keys to reducing maternal and fetal complications. Antihypertensive treatment should be used in women with high-risk chronic hypertension, whereas drug therapy does not improve pregnancy outcome in women at low risk. Prophylactic low-dose aspirin started early in pregnancy in women with chronic hypertension is not effective in reducing the frequency of superimposed preeclampsia and should be avoided.

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.

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.

Pregnancy in chronic renal insufficiency and end-stage renal disease

Childbearing is important to women with renal disease, but pregnancy has generally been regarded as very high risk in these women. In this review, an attempt is made to clarify the nature and severity of those risks in the settings of chronic renal insufficiency and end-stage renal disease, including dialysis patients and transplant recipients. Hypertension is the most common life-threatening problem in all three groups. A wide range of antihypertensive medications have been used, with angiotensin-converting enzyme inhibitors the only drugs absolutely contraindicated because of their association with neonatal anuria, pulmonary hypoplasia, and neonatal death. Women with serum creatinine levels of 1.4 mg/dL or greater are at risk for accelerated loss of renal function compared with women who don't become pregnant. Transplant recipients have a risk for loss of renal function similar to controls as long as renal function is well preserved. The frequency of conception is decreased in women with renal insufficiency and markedly decreased in dialysis patients (0.5% per year). Return of fertility is the rule in transplant recipients. Exposure to immunosuppressive drugs, including prednisone, azathioprine, cyclosporine, and tacrolimus, has not been associated with an increase in congenital anomalies. These drugs, particularly cyclosporine, have been associated with small-for-gestational-age babies. Transplant recipients are at risk for infections that have implications for the fetus, including cytomegalovirus, herpes simplex, and toxoplasmosis. All groups have an increased risk for prematurity and intrauterine growth restriction. The percentage of pregnancies resulting in surviving infants in women with renal insufficiency and transplant recipients ranges from 70% to 100%. For women who conceive after starting dialysis, the likelihood of a surviving infant is approximately 50%.

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

OBJECTIVE

To assess the efficacy and safety of labetalol compared with methyldopa in the management of mild and moderate cases of pregnancy-induced hypertension (PIH).

METHODS

One hundred four primigravidas with PIH were randomly allocated to receive either labetalol (group A) or methyldopa (group B). The dose of the drugs was doubled every 48 h to maintain a mean arterial blood pressure < or = 103.6 mmHg. Clinico-biochemical effects and frequency of side effects were studied. The statistical level of significance was taken at P < 0.05.

RESULTS

Ten patients in group B (18.5%) developed significant proteinuria (> 30 mg/dl) whereas none developed proteinuria in group A. Labetalol was quicker and more efficient at controlling blood pressure, having a beneficial effect on renal functions and causing fewer side effects compared with methyldopa. The rate of induction of labor and rate of cesarean section for uncontrolled PIH was less in group A (48% and 1%, respectively) compared with group B (63.0% and 5.6%, respectively). Moreover a higher Bishop score at induction of labor was noticed in group A.

CONCLUSIONS

Labetalol is better tolerated than methyldopa, gives more efficient control of blood pressure and may have a ripening effect on the uterine cervix.

Labetalol in hypertension during the third trimester of pregnancy: its antihypertensive effect and pharmacokinetic-dynamic analysis

The hypotensive effect, kinetics, and concentration-response relationship of labetalol, alpha beta- and alpha 1-adrenoceptor blocking drug, were studied in seven women with a moderate-to-severe hypertension (averaged diastolic blood pressure [DBP] of 100 to 120 mm Hg measured during a 1- to 2-day hospitalization period) during the third trimester of pregnancy who received the oral twice-daily doses of 150 to 450 mg. These dosages were individually selected by attaining a therapeutic goal of DBP < or = 100 mm Hg or systolic blood pressure (SBP)/DBP reduction of > 30/15 mm Hg, as compared with the pretreatment value, at any time during the 12-hour dosing interval for a 3- to 5-day dosage escalation period. Labetalol concentrations in plasma were measured by a high-performance liquid chromatography with fluorescence detection, and the plasma drug concentration-response relationship was analyzed by a sigmoidal Emax model. Labetalol decreased significantly (P < 0.05 to 0.01) the pretreatment SBP/DBP (166.3 +/- 5.2/110.3 +/- 3.0 mm Hg, mean +/- SEM) without any recognizable side-effects during the twice-daily dosing period in the mothers. Peaked concentrations occurred at 1 hour postdose in all patients. The elimination half-lives ranged from 4.3 to 6.9 hours, and the apparent oral clearance from 31.9 to 73.3 mL/min/kg. The pharmacodynamic parameters (Emax and EC50) analyzed by the Emax model revealed a 3- to 5-fold interindividual variability. The gestational ages at delivery ranged from 34 to 37 weeks, and the birth weights were < 2000 g in 6 of the 7 neonates. Four neonates developed respiratory distress syndrome after delivery, and one infant died of pulmonary hypoplasia 3 months later. The results indicate that 1) labetalol orally administered in a twice-daily regimen as done in this study is an effective antihypertensive drug in women with hypertension during late pregnancy, and 2) interindividual variability in the kinetic factor (e.g., oral clearance) as well as that in the pharmacodynamic factor (e.g., EC50) appear to be related to the overall variability in the hypotensive responsiveness to the drug. However, whether labetalol and/or hypertension per se would have been related to the fetal outcome remains unanswered from the present study.

A randomised placebo controlled trial of labetalol in the treatment of mild to moderate pregnancy induced hypertension

OBJECTIVE

To determine the need for, and efficacy of, treatment with labetalol in women with mild-to-moderate pregnancy induced hypertension (PIH).

DESIGN

Prospective double-blind randomised placebo controlled study.

SETTING

Maternity units of five hospitals in the Trent Region.

SUBJECTS

144 women (86 primigravid) who developed PIH after 20 weeks gestation.

INTERVENTIONS

Treatment with oral labetalol up to 600 mg daily or placebo with subsequent care of treatment failures in accordance with the attending obstetrician's practice.

MAIN OUTCOME MEASURES

Number of days spent as an antenatal inpatient; the development of proteinuria; the perceived need for induction of labour or elective caesarean section; and gestation age at delivery.

RESULTS

Labetalol significantly lowered the blood pressure and reduced the incidence of proteinuria. However, neither the number of days spent as an antenatal inpatient, nor the perceived need for induction of delivery or elective caesarean section, nor the gestation age at delivery differed significantly between the two treatment groups. Post-randomisation consideration of early (< or = 32 weeks) and late (> 32 weeks) onset groups showed the placebo treated early-onset group (n = 15) to have more patients with severe hypertension (> 150/110 mmHg) and a greater requirement for additional antihypertensive therapy prior to labour than the group treated with labetalol (n = 16).

CONCLUSION

Anti-hypertensive intervention therapy in pregnancy induced hypertension has been examined using a placebo controlled randomised double-blind trial of labetalol in pregnancy. The maximum blood pressure prior to labour and the incidence of proteinuria was reduced in women on active therapy. However, the length of gestation was not significantly prolonged and indices of clinical outcome were not significantly altered. The appropriateness of pharmacological therapy for late-onset PIH may be questioned.

Diversity of blood pressure recording during pregnancy: implications for the hypertensive disorders

OBJECTIVE

To determine the number and type of methods used to measure blood pressure (BP) in pregnant women.

DESIGN

Questionnaires were distributed to obstetricians and midwives concerning: method of recording BP (arm used, subject position, Korotkoff sounds recorded); accuracy of recording BP (cuff size, sphygmomanometer calibration); and definitions of hypertension in pregnancy.

PARTICIPANTS

Obstetricians (academic, staff and private) in Sydney; members of the New South Wales Midwives' Association.

MAIN RESULTS

Responses were received from 85 obstetricians (55% of those surveyed) and 173 midwives (43%); the overall response rate was 46%. Almost 80% of respondents agreed that diastolic BP above 90 mmHg constituted hypertension during pregnancy but at least six different methods were used to obtain BP readings, with a potentially large variability in the BP so obtained. Forty-five per cent of obstetricians and 72% of midwives stated that they always used a large cuff when necessary. Few had had their sphygmomanometer calibrated within the previous two years.

CONCLUSIONS

There is considerable variability in the way BP is recorded in pregnant women. Hypertension in pregnancy may therefore be over or under diagnosed according to the method employed and there is an urgent need for international consensus on how to measure BP accurately in pregnancy.

High blood pressure during pregnancy and working conditions among hospital personnel

The relationship between working conditions and high blood pressure during pregnancy was analysed in a sample of 621 women hospital employees in the Paris region over the period 1979-1981. Data were collected by interviews during the routine medical visit at the end of postnatal leave. Women who had to work standing up for extended periods of time, who had to carry heavy loads or who had to perform heavy cleaning tasks had high blood pressure during their pregnancy more often than women not exposed to these working conditions. The accumulation of two out of the three or these three working conditions by the same woman was strongly related to high blood pressure. This relation remained significant when other risk factors of hypertension, such as age, parity, corpulence and tobacco use, were taken into account in a multiple logistic regression.

Betaxolol: a pilot study of its pharmacological and therapeutic properties in pregnancy

Twenty two pregnant women with mild to moderate hypertension were treated with betaxolol (10-40 mg/day), a cardioselective beta adrenoceptor blocking agent. The analysis of the changes from the baseline confirmed the antihypertensive effect of the drug with a mean decrease in SBP of 11.8 mm Hg and in DBP of 8.3 mm Hg. A diastolic BP less than 90 mm Hg was obtained in 20 patients after the first day of therapy. Fetal safety, assessed by ultrasonography and cardiotocographic recording was excellent. The 22 mothers gave birth to 23 live born babies (one twin pregnancy). Mean Apgar scores were 8.3 and 9.1 at 1 and 5 min. Only 1 newborn had an Apgar score less than 7. Three newborns suffered from fetal distress and 1 from threat for causes not related to therapy. At 9 months follow-up, all 23 babies were in good health. These data suggest that betaxolol is effective in reducing maternal blood pressure without any deleterious effect on the foetus and the newborn.

Placental transfer and perinatal pharmacokinetics of betaxolol

Betaxolol levels in blood were monitored in the perinatal period in 28 pregnant hypertensive women and in their babies. In the mothers betaxolol concentrations at delivery ranged from less than 1 to 115 ng.ml-1 after doses of 10 to 40 mg.day-1. The apparent blood half-life was 15.6 to 22.1 h mean (19 h). Umbilical cord levels indicated a rapid equilibrium between fetal and maternal units (ratio 0.93) within few hours after dosing. Milk betaxolol concentrations, measured in few cases, exceeded those in blood by a factor of 3. Amniotic fluid concentrations were similar to those observed in maternal venous blood and umbilical cord blood. In neonates, the blood betaxolol half-life ranged from 14.8 to 38.5 h, with a definite trend towards a negative correlation with gestational age. A 11-61% rise in the betaxolol concentration was observed in 64% of the neonates during the first 12 h of extrauterine life. The data indicate that betaxolol kinetics is not altered in pregnant women and they stress the need for careful and prolonged (72-96 h) intensive monitoring of neonates born to hypertensive mothers treated with beta-blocking agents.

A randomized comparison of early with conservative use of antihypertensive drugs in the management of pregnancy-induced hypertension

Two treatment strategies were compared in 155 women with pregnancy-induced hypertension who were also given comprehensive non-pharmacological care. The mean gestation at entry was 28 weeks. As long as the diastolic blood pressure (DBP) remained below 106 mmHg, oxprenolol, or oxprenolol plus dihydralazine, were given to the early treatment group, and matching placebos to the control group. Open antihypertensive treatment was provided for patients whose DBP rose above 105 mmHg. Proteinuria occurred in seven women in each group. In the early treatment group, 13 of the 78 women were delivered by caesarean section; the corresponding numbers in the control group were 27 of 76 (17 vs 36%, 95% confidence interval (CI) of difference: 5-33%); the sections included seven and 16 in the early treatment and control groups, respectively, for severe hypertension and/or fetal distress. There were five perinatal deaths, two in the early treatment group and three in the control group. Early treatment did not influence gestational age at birth or birthweight. Respiratory distress syndrome occurred in four infants in the early treated group and in 10 in the control group; 14 infants in the former group and 26 in the latter were in hospital for more than 10 days (18 vs 35%; 95% CI of difference 4-32%). These results indicate that early antihypertensive treatment with oxprenolol is safe for the fetus and newborn in pregnancy-induced hypertension, but has no advantage over non-pharmacological care in terms of fetal growth. However, it may prevent acute hypertension in late pregnancy and associated fetal distress, and thus reduce the number of caesarean sections.