Hypertension in

Pregnancy

Dr.Rafi RozanObstetrician & Gynecologist

Specialist in Comprehensive Family Medicine

Medical Technologist

Classification of Hypertensive

disorders

• Preeclampsia-Eclampsia

• Chronic Hypertension

• Chronic Hypertension with Superimposed

Preeclampsia

• Gestational hypertension

Epidemiology and Risk factors

• 1st degree relative (2-4x)

• Previous pregnancy (7x)

• Multiple gestation

• AMA, DM, obesity, preexhisting HTN

• IVF

• History of thrombocytopenia

• SLE

Predicting preeclampsia

• Uterine artery doppler velocimetry

-increased resistance to flow abnormal waveforms(increasedresistance or pulsatility indices with persistence of diastolic notch)

-low predicitve value alone

• Biomarkers (angiogenesis related and placental protein 13)- none currently recommended. Future studies needed

• Screening to predict preeclampsia beyond obtaining an appropriate medical history to evaluate for risk factors is not recommended

Preeclampsia-Eclampsia

• Pregnancy specific hypertensive disease with

multisystem involvement

• >20w of gestation

• Most common: HTN + Proteinuria

• Without Protein: thrombocytopenia, impaired LFTs,

the new development of renal insufficiency,

pulmonary edema, cerebral or visual disturbances

Preeclampsia-Eclampsia

• Hypertension: mild >140/90. at least 2 readings 4h apart. Severe >160/110 diagnosis can be confirmed within shorter interval to facilitate timely antihypertensive therapy

• Proteinuria: 300mg in 24h, Protein:Creatinine ratio >0.3 on random void, 1+ dipstick

• Eclampsia: convulsive phase

• “mild preeclampsia” and “severe preeclampsia” are not specific classifications and should be replaced by preeclampsia with or without severe features

Assessing the severity of

Preeclampsia

Establishing the diagnosis

• Taking a BP

-patient seated, legs uncrossed, back and arm supported

-middle of the cuff on the upper arm at the level of the right atrium (midpoint of sternum)

-pt to relax and not talk for 5 minutes prior to BP reading

-wait several minutes before repeating if elevated

-BP taken in upper arm with woman in left lateral position will be falsely low

Prediagnostic findings warranting

increased surveillance

• New onset headache, visual disturbance, RUQ pain, epigastric pain

• New onset proteinuria in second half of pregnancy

• Fetal growth restriction

• Biochemical markers (uric acid) value of management of specific patients. Associated with poorer outcomes. Should not be used to support the initiation of specific interventions by themselves

• Edema or rapid weight gain: nondiagnostic

Eclampsia

• New onset grand mal seizures in woman with preeclampsia

• Can occur before, during, or after labor

• Differential: bleeding AV malformation, ruptured aneurysm, idiopathic seizure disorder

• Alternative diagnosis may be more likely if seizures occur after 48-72h postpartum or when new seizures occur during use of antiepileptic therapy with magnesium sulfate

Chronic Hypertension

• High BP known to predate conception

• High BP detected before 20w

Chronic Hypertension with

superimposed preeclampsia

• Incidence preeclampsia 4-5x that in nonhypertensivepregnant women

• Women with HTN who develop proteinuria after 20w and women who have proteinuria before 20w who:

-Need to escalate antihypertensive treatment

-increased LFTs

-Plts <100,000

-RUQ pain or HA

-Pulmonary edema

-Cr >1.1 or doubled

-sudden increase in proteinuria

Gestational Hypertension

• New elevations in BP in the absence of proteinuria

• Failure of BP to normalize postpartumchange

diagnosis to chronic hypertension

• Women with BP elevation to severe level have

similar outcomes to women with preeclampsia

• Require enhanced surveillance

Management of preeclampsia

and HELLP syndrome

• Initial Evaluation

• CBC, Cr, LFTs

• 24h urine protein collection or protein:creatinine ratio

• Evaluate for symptoms

• Fetal evaluation: EFW, AFI, NST

• Continued evaluation:

• Daily kick count

• Fetal growth US q3w

• AFI q week

• NST q week (gHTN), NST twice weekly (Preeclampsia without severe features)

• Twice weekly BP

• Assess for proteinuria weekly (gHTN)

• Weekly labs

Management of preeclampsia

and HELLP syndrome

• Antihypertensive Therapy:

• Decrease progression to severe range BP

• Increase fetal growth restriction

• No effect on development of preeclampsia, eclampsia,

pulmonary edema, fetal or neonatal death, preterm birth

Management of preeclampsia

and HELLP syndrome

• Intrapartum management

• Timing of delivery 37w0d IOL

-Lower risk of new onset severe features, HELLP syndrome, eclampsia

-No difference neonatal morbidities or cesarean

• Magnesium Sulfate

-studies not powered to demonstrate signifcant reduction in eclampsia

-routine magnesium sulfate not indicate in Preeclampsia without severe features

• Antihypertensive therapy: BP>160/110. decrease CV, renal, cerebrovascular events

-Labetalol or hydralazine

-Nifedipine controversial: theoredical risk if on mag. Excessive hypotension and neuromuscular blockade

Management of preeclampsia

and HELLP syndrome

• Severe Preeclampsia

• Progressive deterioration of maternal and fetal conditions if delivery not pursued

• Delivery at 34w0d

• Prompt delivery in pulmonary edema, renal failure, abruptio placenta, severe thrombocytopenia, DIC, persistent cerebral symptoms, nonreassuring fetal testing or fetal demise irrespective of GA less than 34w

• Corticosteroids for fetal lung maturity: for women <34w, decrease RDS and IVH

• Severe Proteinuria: resolution of renal dysfunction by 3 months. no difference in rates of eclampsia, placental abruption, pulmonary edema, HELLP, neonatal death/morbidity

• Previable Preeclampsia should not be expectantly managed

• Mode of delivery should be determined by fetal GA, fetal presentation, cervical status, maternal-fetal condition

Management of preeclampsia

and HELLP syndrome

• Eclampsia

• Magnesium sulfate superior to phenytoin and diazepam

• Continue mag for 24h after last convulsion

• Loading 4-6g followed by 1-2g/hr

• HELLP (hemolysis, abnormal LFTs, thrombocytopenia)

• Delivery delayed for fetal steroids

• Cochran review demonstrating inprovement of platelet levels

following steroids, no improvement of morbidity/mortality

Management of preeclampsia

and HELLP syndrome

• Postpartum

• BP decrease within 48h

• BP increases again 3-6d PP

• NSAIDs can raise BP suggest replacing if BP

persistently elevated for 1d PP

• Recommend BP monitoring for 72h PP and again 7-

10d PP

• Antihypertensive therapy if BP> 150/100 on 2

occasions 4-6h apart

• 24h mag for women with HTN and severe features

Preconceptual counseling

Chronic hypertension in pregnancy and

superimposed preeclampsia

• Uncomplicated cHTN higher rates of cesarean and PP

hemorrhage

• Superimposed preeclampsia 13-40% pregnancies with cHTN

• Avoid ACEi, ARBs mineralicorticoids and statins

• Initial eval:

• baseline HELLP labs and urinalysis

• ECHO if cHTN >4y

• Home BP monitoring suggested. Ambulatory monitoring

good to rule out white coat HTN

Chronic hypertension in pregnancy and

superimposed preeclampsia

• Initiate antihypertensive therapy for BP >160/105

• Suggested to maintain BP 120-160/80-105

• 10mmHg decrease in mean arterial pressure has been shown to decrease fetal weight by 145g

• Medications in pregnancy: labetalol, nifedipine, methyldopa

• Incidence SGA 8-15.5% (growth US, doppler PRN)

• Deliver at 38w

Chronic hypertension in pregnancy and

superimposed preeclampsia

• Superimposed Preeclampsia

• Without severe features: new proteinuria or increasing

BP

• Does not require antihypertensive therapy if BP

<160/105

• Avoid mag

• Superimposed preeclampsia with severe features

• Expectantly managing <34w steroids

• Magnesium for seizure prophylaxis(2.4%)

Prevention of Preeclampsia

• Alterations in systemic prostacyclin-thromboxane balance

• Inflammation increased

• Meta-analysis 30,000 women from 31 trials: ASA modest benefit with RR 0.9

• Cochran review 59 trials and 37,000 women: 17% reduction with significant reduction in high risk patients

• High risk women: cHTN, DM, previous preterm preeclampsia (number needed to treat=50)

• Initiate in late 1Trimester for women with a medical history of early onset preeclampsia and preterm delivery less than 34w or Preeclampsia in more than 1 pregnancy

Prevention of Preeclampsia

• Calcium supplementation (1.5-2g) may be considered in pregnant women from populations with low baseline calcium intake (less than 600mg/d)

• Dietary salt should not be restricted. Meta analysis of 7,000 patients suggest diuretics do not reduce preeclampsia

• Oxidative stress contributes to Preeclampsia: Vitamin C and Vitamin E with no benefit in prevention

• Bedrest not recommended: further studies need examining exercise

References

• ACOG task force: Hypertension in pregnancy

• ACOG Committee opinion 623: Emergent therapy

for acute onset, severe hypertension during

pregnancy and the postpartum period