chronic htn - royan-edu.ir

CHRONIC HTNDR Neda Hashemi

Fellowship of PerinatologyRasoul Akram Hospital

Iran University of Medical Science

DEFINITION/DIAGNOSTIC CRITERIA

Blood pressure criteria for hypertension in pregnancy are systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg, or both.

Severe hypertension is defined as systolic blood pressure ≥160 mmHg, diastolic blood pressure ≥110 mmHg, or both.

In pregnant women who first present for prenatal care in the second trimester without recent prepregnancy blood pressure measurements for comparison, the diagnosis of chronic hypertension can be missed due to the normal physiologic decrease in blood pressure between 12 and 19 weeks of gestation: systolic and diastolic blood pressures are approximately 5 to 10 mmHg below baseline at this time.


In pregnant women, chronic hypertension (also called preexisting hypertension) can be defined as hypertension known to be present before conception or first recognized before 20 weeks of gestation.

In women with a previous pregnancy complicated by gestational hypertension, hypertension that persists 12 or more weeks post-delivery is also considered chronic


the American College of Cardiology (ACC) and the

American Heart Association (AHA) modified the traditional

criteria for diagnosing hypertension in nonpregnantadults to better identify and

modify long-term cardiovascular risk.


The new criteria, in nonpregnant adult:

Elevated blood pressure – Systolic blood pressure 120 to 129 mmHg and diastolic blood pressure <80 mmHg.

Stage 1 hypertension – Systolic blood pressure 130 to 139 mmHg or diastolic blood pressure 80 to 89 mmHg.

Stage 2 hypertension – Systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg.(Chronic HTN)


Emerging evidence suggests that women with stage 1 hypertension

may be at increased risk of developing preeclampsia,

gestational diabetes, and indicated preterm birth compared with

women with normal blood pressures (<120 mmHg systolic and

<80 mmHg diastolic) at the first-trimester visit.

RISKS OF CHRONIC HYPERTENSION IN PREGNANCY

Chronic hypertension and

cardiovascular disease are among the leading causes of maternal and fetal/neonatal morbidity and

mortality.

Superimposed preeclampsia,

which develops in 13 to 40 percent of pregnant women

with chronic hypertension, is associated with higher rates of

adverse outcomes

MATERNAL RISKS

Acute kidney failure – 5.9 per 1000 deliveries Pulmonary edema – 1.5 per 1000 deliveries Superimposed preeclampsia – 13 to 40 percent In-hospital mortality – 0.4 per 1000 deliveries Stroke/cerebrovascular complications – 2.7 per 1000

deliveries Cesarean delivery – Estimated prevalence 41.4 percent Placental abruption Postpartum hemorrhage Gestational diabetes – 8.1 percent Hospitalization – Mean inpatient length of stay for chronic

hypertension without preeclampsia 5.4 days and 12.7 days for superimposed preeclampsia; odds of length of stay >6 days

FETAL/NEONATAL RISKS

Perinatal mortality

Preterm birth, low birth weight,

neonatal intensive care unit admission

Small for gestational age

Congenital malformations

LONG-TERM PROGNOSIS

Maternal – Both chronic hypertension and preeclampsia are clearly associated with increased cardiovascular risk in later life in women.

Offspring – The existing data on long-term offspring outcomes of pregnancies complicated by chronic hypertension are largely population-based and do not always account for preeclampsia, medication use, severity of disease, and gestational age at birth.

With these limitations, long-term follow-up of offspring of pregnancies complicated by hypertensive disorders in the Helsinki Birth Cohort showed a modest association with self-reported cognitive decline and mental and mood disorders

PRECONCEPTION CARE

Counseling – Counseling is provided about the pregnancy risks of chronic hypertension and the potential interventions to minimize these risks.

Patients are informed about the anticipated course of pregnancy, need for heightened maternal and fetal surveillance, and likely need for more frequent obstetric visits and possibly hospitalization (if superimposed preeclampsia develops) compared with a low-risk population.

PRECONCEPTION CARE

Consideration of secondary causes of hypertension – While the majority of

hypertensive, reproductive-age women with chronic hypertension have essential (idiopathic or primary) hypertension, consideration of secondary causes of hypertension is important if not already evaluated, since these causes can require specific

testing and therapy, ideally before pregnancy.

A finding suggestive of secondary hypertension is resistant hypertension, particularly in younger

women (<30 years) with no family history of hypertension.

PRECONCEPTION CARE

Laboratory tests: Creatinine

Urine protein/creatinine ratio or 24-

hour urine protein

If abnormal, additional

information on issues in pregnant

women with chronic kidney

disease is discussed in detail separately

PRECONCEPTION CARE

Cardiac evaluation – Baseline cardiac evaluation is recommended in women with long-standing hypertension, based on age or poorly controlled hypertension for more than four years, given the increased risk of cardiac hypertrophy, dysfunction, and ischemic heart disease.

Because of the enhanced detection of left ventricular hypertrophy and cardiac dysfunction, practtioner utilize transthoracic echocardiography for baseline cardiac evaluation. When echocardiography is not available, a twelve-lead electrocardiogram can be used as an alternative first-line test.

PRECONCEPTION CARE

Blood pressure management – Blood pressure is optimized, with attention to an antihypertensive regimen with a favorable safety profile in pregnancy. In particular, angiotensin converting enzyme inhibitors and angiotensin receptor blockers should be avoided since they have been associated with fetal malformations, including renal dysgenesis and calvarial hypoplasia, as well as fetal growth restriction and oligohydramnios.

Labetalol and nifedipine have a good fetal safety profile and are first-line options. Methyldopa is considered safe in pregnancy but may be less effective in controlling blood pressures

PRECONCEPTION CARE

Modifiable risk factors – Weight loss in overweight and obese patients, smoking cessation in smokers, increased exercise for sedentary individuals, and dietary changes (sodium restriction, Dietary Approaches to Stop Hypertension [DASH] diet) when appropriate are encouraged as nonpharmacologic means of reducing blood pressure and potentially improving pregnancy outcome and overall health

PRENATAL CARE AND DELIVERY Women with chronic hypertension — The

following discussion applies to the prenatal care and delivery of women with chronic hypertension.

Monitoring for development of superimposed preeclampsia is a key component of the prenatal care of these women.

If it develops, pregnancy management needs to be modified because preeclampsia is a progressive and potentially life-threatening disease

BASELINE CLINICAL EVALUATION ANDLABORATORY TESTING

Clinical evaluation should include baseline blood pressure and heart rate and a general physical examination, including cardiopulmonary auscultation and evaluation for any signs of cardiac dysfunction (cyanosis, hepatomegaly, jugular venous distention, pulmonary edema)

In addition to routine prenatal laboratory testing, the following laboratory tests are recommended, if not obtained within the six months prior to conception:

Creatinine

Urine protein/creatinine ratio or 24-hour urine protein


We also obtain liver transaminases (aspartate aminotransferase and alanine aminotransferase) and a platelet count as a baseline,

as this information is useful if the patient exhibits signs/symptoms of preeclampsia later in pregnancy.

We obtain electrolytes in patients with renal dysfunction.

If not assessed within one year prior to conception, transthoracic echocardiography or twelve-lead electrocardiogram are suggested

for women with long-standing hypertension,based on age or poorly controlled hypertension for more than four years.

Cardiac dysfunction increases morbidity in pregnancy and delivery given the increase in cardiac output and cardiac stress.


Accurate gestational dating is particularly important given the increased risks for growth restriction and indicated preterm delivery in patients with chronic hypertension. Whether to perform an ultrasound examination in the first trimester or wait until the time of the 18- to 20-week fetal anatomic survey depends on the clinician's confidence in the menstrual dates.

Low-dose aspirin is recommended after 12 weeks of gestation for prevention of preeclampsia as these patients are at high risk of developing the disease.

Some have advocated doses of ≥100 mg daily based on a meta-analysis of eight trials.

DIET AND GESTATIONAL WEIGHT GAIN

Women should be encouraged to meet gestational weight gain targets that are appropriate for their body mass index.

In particular, excessive gestational weight gain should be avoided because increased adiposity is strongly associated

with higher blood pressure. Excessive gestational weight gain can also lead to significant postpartum weight retention.

There is minimal information on the effects of initiating a low salt or Dietary Approaches to Stop Hypertension (DASH) diet

before pregnancy or continuing it throughout pregnancy.

These are healthy dietary approaches and would be reasonable to continue during pregnancy

ONGOING MATERNAL MONITORING

Obstetric provider visits should include evaluation of blood pressure and potential symptoms of superimposed preeclampsia.

More frequent visits than standard schedules (every 4 weeks until 28 to 30 weeks, every 2 weeks until 35 weeks, then weekly) for blood pressure monitoring may be needed in the setting of poorly controlled blood pressure or if ongoing medication titration is needed


Blood pressures should be measured with the appropriate sized cuff, proper positioning, and rest period.

Home blood pressure monitoring is reliable, useful to complement office visits, and may reduce office visits and the need for hospitalization .

While worsening blood pressure, possibly in the late second trimester and more commonly in the third trimester, could indicate the anticipated physiologic rise in blood pressure in the second half of pregnancy, superimposed preeclampsia must be excluded, based on gestational age at onset, symptoms and laboratory studies, risk factors, and course over time.

We recommend a low threshold for in-hospital evaluation if superimposed preeclampsia is suspected.


Patient education on the symptoms and signs of preeclampsia and clear instructions on when to

contact providers are essential.

Symptoms of persistent and/or severe headache, visual changes (scotomata, photophobia, blurred

vision, or temporary blindness [rare]), right upper quadrant or epigastric pain, new onset of nausea or vomiting in the third trimester, new

onset of shortness of breath, altered mental status, or vaginal bleeding warrant additional

investigation

BLOOD PRESSURE MANAGEMENT

The optimal treatment of

chronic hypertension in

pregnancy, particularly mildly

elevated blood pressure, continues

to be debated.

Many studies combine patients

with chronic hypertension and

gestational hypertension,

which may represent different pathophysiologic

mechanisms.

BLOOD PRESSURE MANAGEMENT

Severe hypertension — Regardless of etiology (chronic hypertension, gestational hypertension, preeclampsia), there is consensus among medical organizations that severe maternal hypertension (systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥110 mmHg) should be pharmacologically treated in a timely manner to reduce maternal cerebrovascular, cardiac, and renal events as well as death.

NONSEVERE HYPERTENSION

Patients not on antihypertensive therapy and without end-organ disease – For women with nonsevere hypertension (systolic blood pressure ≥140 and <160 mmHg or diastolic blood pressure ≥90 and <110 mmHg) who are not on antihypertensive therapy and have no end-organ involvement, we generally initiate this therapy when blood pressures approach the severe range in order to prevent development of severe maternal hypertension while minimizing fetal exposure.

After initiation of therapy, target blood pressure continues to be an area of controversy. Our target blood pressure range is 120 to 150/80 to 95 mmHg; a target range of 130 to 150/80 to 100 mmHg is also common.


Patients on antihypertensive therapy and without end-organ disease – For women with nonsevere hypertension on antihypertensive therapy with no end-organ involvement, our decision making is individualized.

For most women with well-controlled blood pressures on an antihypertensive medication regimen with a good safety profile, it is reasonable to continue medications to decrease the occurrence of severe hypertension.However, it is also reasonable to discontinue medications during the first trimester to minimize fetal exposure and restart them if blood pressures approach severe range.


Patients with end-organ disease – For women with nonseverehypertension and end-organ involvement, such as cardiac or renal disease, the threshold for initiating or

continuing antihypertensive therapy is lower: systolic blood pressure ≥150 mmHg or diastolic blood pressure ≥100 mmHg.

After initiation of therapy, it may be desirable to maintain blood pressure at 120 to 140/80 to 90 mmHg, though whether lowering blood pressure to a "normal" level (120/80 mmHg) would confer maternal benefit is unresolved .

The American Diabetes Association suggests treating pregnant women with diabetes and consistent blood pressures >135/85 mmHg, with the blood pressure target no lower than 120/80 mmHg

American College of Obstetricians and Gynecologists (ACOG) – ACOG recommends

not initiating medication therapy for mild chronic hypertension in pregnancy (>140/90 mmHg and

<160/110 mmHg) given the limited evidence for a clear benefit and safety of treatment.

In addition, ACOG recommends considering discontinuing medication in women with mild

hypertension who become pregnant and recommending lifestyle modifications (diet,

exercise).

Pharmacologic therapy is recommended for pregnant women with severe hypertension (systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥105 to 110 mmHg) since the short-term benefits for women and fetuses are

well-defined.

A lower threshold for initiation of medications (≥150/100 mmHg) is recommended for women with end-organ involvement, such as cardiac

or renal disease.

For most women, the blood pressure target is systolic blood pressure ≥120 and <160 mmHg and diastolic blood pressure ≥80

and <110 mmHg.

National Institute for Health and Care Excellence (NICE) – NICE guidelines recommend offering treatment for systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg, with

goal blood pressures of <135/85 mmHg [55].

International Society for the Study of Hypertension in Pregnancy (ISSHP) – The

ISSHP recommends pharmacologic therapy to keep blood pressures in the range of 110 to 140 mmHg/80

to 85 mmHg during pregnancy

EVIDENCE OF POTENTIAL BENEFITS OFTREATMENT

The body of data The body of data indicates that treatment of

chronic hypertension in

pregnancy reduces the

occurrence of severe

hypertension.

Treatment does Treatment does not appear to significantly reduce other

adverse pregnancy outcomes;

however, these data are less consistent.

TESTS TO MONITOR FETAL WELL-BEING

We suggest daily assessment of fetal kick counts starting at 28 weeks of gestation; <10 fetal movements in two hours should prompt further assessment of fetal well-being.

Maternal assessment of fetal movement, or fetal kick counts, is an inexpensive and easily implemented method to assess fetal well-being and, when normal, generally reassuring to mothers; however, its value for reducing perinatal mortality is unproven

TESTS TO MONITOR FETAL WELL-BEING

We initiate twice weekly fetal surveillance at 32 weeks of gestation because routine surveillance is unlikely to improve perinatal outcomes when implemented earlier in gestation.

Twice weekly rather than weekly fetal testing is performed based on limited evidence suggesting a reduction in fetal deaths with frequent testing.

Comparison of serial non stress tests, biophysical profiles (BPPs), or modified BPPs reveals no significant difference in perinatal mortality rates associated with any specific modality of fetal surveillance.

The choice among these tests should be based on provider preference and other local factors.

TIME TO DELIVERY

ACOG suggested the following approach for delivery of women with chronic hypertension:

≥38+0 to 39+6 weeks of gestation for women not requiring medication

≥37+0 to 39+0 weeks for women with hypertension controlled with medication

34+0 to 36+6 weeks for women with severe hypertension that is difficult to control

INTRAPARTUM CARE

Cesarean delivery should be reserved for standard obstetric indications.

Intrapartum magnesium sulfate therapy for seizure prophylaxis is not indicated in the absence of superimposed preeclampsia as the risk of seizure is less than 0.1 percent.

In women with chronic kidney disease on magnesium sulfate for fetal/neonatal neuroprotection, close maternal monitoring is essential for prevention and early recognition of magnesium toxicity.

INTRAPARTUM CARE

The goal of intrapartum blood pressure management is to The goal of intrapartum blood pressure management is to prevent maternal cerebrovascular or coronary events while minimizing rapid fluctuations in blood pressure that could

influence uterine perfusion.

Antihypertensive medication regimens started prior to labor should be continued intrapartum.

Rapid-acting medications should be used for blood Rapid-acting medications should be used for blood pressures ≥160 mmHg systolic or ≥110 mmHg diastolic that persist for 15 minutes or more, with intravenous

labetalol or hydralazine the preferred first-line agents.ACOG endorses use of immediate-release oral nifedipine as ACOG endorses use of immediate-release oral nifedipine as a first-line option for emergency treatment of acute, severe hypertension in pregnancy, particularly when intravenous

access is not in place.

INTRAPARTUM CARE

Volume status (fluid intake and output) should be recorded, with the goal of maintaining euvolemia.

Maintenance of euvolemia during labor is particularly important in women with a long-standing history of hypertension and left ventricular hypertrophy and/or diastolic dysfunction, as they are predisposed to pulmonary edema with volume overload, whereas volume depletion can lead to tachycardia and reduced filling times, exacerbating any preexisting diastolic dysfunction

WOMEN WITH SUPERIMPOSEDPREECLAMPSIA

Definition/diagnostic criteria — Preeclampsia is considered superimposed when it occurs in a

woman with preexisting chronic hypertension. In women with chronic hypertension,

distinguishing superimposed preeclampsia from third-trimester physiologic increases in blood pressure and proteinuria can be challenging.


A sudden increase in blood pressure that was previously well-controlled or a need for a rapid escalation of antihypertensive medications to control blood pressure.

The new onset of proteinuria or a sudden increase in proteinuria in a woman with known prepregnancy or early pregnancy proteinuria. A sudden increase in proteinuria is not precisely defined by various societies or in the existing literature.

Based on limited evidence, we typically diagnose superimposed preeclampsia when the level of proteinuria increases 100 percent from baseline in women with preexisting renal disease or proteinuria


The presence of any of the following severe features of The presence of any of the following severe features of preeclampsia supports the diagnosis of superimposed preeclampsia with severe features

Severely elevated blood pressure despite increasing antihypertensive therapy.

Thrombocytopenia (platelet count <100,000/microliter). Elevated transaminases (two times the upper limit of the

normal concentration for a particular laboratory) or severe persistent right upper quadrant or epigastric pain unresponsive

to medication and not accounted for by alternative diagnoses, or both.

New-onset or worsening renal insufficiency. Pulmonary edema. Persistent cerebral or visual disturbances.


Management — Upon diagnosis of superimposed

preeclampsia, management of women with chronic

hypertension is generally similar to that of other

women with preeclampsia.

POSTPARTUM CARE

Analgesia — The decision to use nonsteroidal anti-inflammatory drugs (NSAIDs) for analgesia should be

individualized as these drugs are known to cause elevations in blood pressure in nonpregnant individuals with

hypertension.

Overall, the body of data supports the safe use of NSAIDs in postpartum patients with blood pressure issues.

If blood pressure is elevated in the postpartum period, we use acetaminophen as our first-line medication for pain management.NSAIDs should be used preferentially over opioid analgesics, when possible. However,practitioner avoid post-delivery NSAID use in

women with preexisting renal disease and/or elevated serum creatinine levels.

POSTPARTUM CARE

Blood pressure management — Blood pressure control is an ongoing issue during the postpartum period, even in women with chronic hypertension who did not require antihypertensive therapy during pregnancy. Blood pressure often declines immediately after delivery and continues to decline for a few days before increasing three to five days after delivery when the woman may already be at home.

The immediate decline is generally attributed to blood loss and the effects of analgesia, while the subsequent increase is likely due to mobilization of extravascular fluid with a rise in intravascular volume, as well as factors such as pain.

Early postpartum visits for a blood pressure check (within 3 to 10 days after delivery) or home blood pressure monitoring, particularly in the first two weeks post-delivery, is recommended.

POSTPARTUM CARE

Family planning — Contraception and appropriate timing of future pregnancies should be discussed.

Estrogen-containing contraceptive agents are generally avoided in women with stage 2 hypertension or higher (systolic blood

pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg), vascular disease, or substantial cardiovascular risks because the theoretic or proven risks generally exceed the benefits, and good

alternatives are available

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