Hypertension%20in%20pregnancy Diagnosis

Preeclampsia/Eclampsia

• Always presents potential danger to the mother and baby; therefore, prevention relies on identifying high-risk women
  • Offer hospital admission to the patient if with clinical concerns and for close clinical and lab monitoring aimed at early recognition and institution of treatment or delivery when indicated

Clinical Blood Pressure (BP) Measurement 

• Patient should be seated quietly for at least 5 minutes in a chair with feet on the floor and arm supported at heart level prior to measurement of BP (or left lateral recumbent position during labor)
• Appropriately-sized cuff should be placed at heart level of the patient and should not be placed over any clothing
• Use the appearance of phase I Korotkoff’s sounds for systolic blood pressure (SBP) and the disappearance of phase V for diastolic blood pressure (DBP)
• Differences of BP between 2 arms should be noted, and the arm with consistently higher measurement should be used for all subsequent BP readings
• Make sure devices to be used are professionally validated specifically in pregnancy and preeclampsia

Confirmation of Elevated BP 

• Definition of hypertension is based on office or in-hospital BP measurements
  • Ambulatory BP monitoring is preferred over routine BP measurement in predicting outcome of pregnancy
• Hypertension in pregnancy is defined as an SBP of ≥140 mmHg or a DBP of ≥90 mmHg, or both, based on at least 2 measurements ≥4 hours apart 
• Diagnosis of severe hypertension is made when SBP is ≥160 mmHg and/or DBP is ≥110 mmHg, and mild when BP is 140-159/90-109 mmHg  
  • Measurement should be repeated after 15 minutes for confirmation of severe hypertension  

Work-up for Chronic Hypertension

• Evaluate patients with preexisting hypertension before pregnancy to define its severity and to facilitate planning for changes in lifestyle and pharmacotherapy if required
• If a woman’s BP elevation is confirmed and especially if it is severe, a woman should be evaluated for potentially reversible causes
• Woman with a history of high BP for several years should be evaluated for target organ damage (TOD)

Presence of Secondary Cause or Evidence of TOD

• Patient should be referred to a specialist and treated appropriately if a secondary cause of hypertension is found
• Further tests should be done, if TOD is found, in order to evaluate the level of severity

Findings that Support the Diagnosis of Severe Preeclampsia

One or more of the following:

• SBP ≥160 mmHg and/or DBP ≥110 mmHg on 2 occasions at least 4 hours apart during bed rest
• Severe persistent epigastric or right upper quadrant pain unresponsive to medications
• New-onset or persistent headache or other cerebral or visual disturbances
• Pulmonary edema and/or congestive heart failure
• Platelet <100,000 cells/mm³ or microangiopathic hemolytic anemia (with increased lactic acid dehydrogenase)
• Elevated liver enzymes (aspartate aminotransferase [AST] or alanine aminotransferase [ALT]) ≥2x the upper limit of normal value
• HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count)
• Severe proteinuria  and oliguria <500 mL/day
• Serum creatinine >1.1 mg/dL or increased to twice the normal concentration without other renal disease

Chronic Hypertension

• Should be taken, if not yet done previously or recently, to exclude secondary causes, risk factors and TOD
  • Complete blood count (CBC), platelet count, urinalysis, renal function test, fasting blood sugar, lipid profile (after 9- to 12-hour fast), serum sodium (Na), potassium (K), uric acid, liver enzymes
  • Chest X-ray
  • 12-lead electrocardiogram (ECG)

Preeclampsia

• It is important to rule out preeclampsia in pregnant women with hypertension
• The following are used to distinguish preeclampsia from chronic hypertension: CBC, platelet count, blood smear, coagulation profile, serum creatinine, uric acid, liver enzymes, serum albumin, lactic acid dehydrogenase, oxygen saturation
• All pregnant women should be checked for proteinuria
  • 24-hour urine collection is recommended but other acceptable methods are urine dipstick test or urine protein:creatinine ratio
  • Proteinuria should be suspected in patients with ≥1+ protein on urine dipstick and followed up with a urine protein:creatinine ratio in a single spot urine sample
  • Confirmation of proteinuria: ≥300 mg in a 24-hour urine sample, ≥30 mg/mmol protein:creatinine ratio in a random or spot urine sample, or ≥2+ protein on urine dipstick
• Other diagnostic work-up that may be considered in patients at risk of developing preeclampsia includes fetal ultrasound for fetal growth and amniotic fluid volume assessment, Doppler ultrasound of the uterine arteries and measurement of soluble fms-like tyrosine kinase-1 (sFlt-1):placental growth factor (PlGF) ratio (angiogenic markers)
  • PlGF-based testing may be done between 20 to 35 weeks of pregnancy to exclude preeclampsia
  • Angiogenic imbalance (eg reduced PlGF [<5th centile for gestational age] or increased sFlt-1:PlGF ratio [>38]) suggests uteroplacental dysfunction 

Preterm Preeclampsia   

• Screen all pregnant women in the 1st trimester for preterm preeclampsia using the following:
  • Maternal characteristics (eg advanced maternal age, obesity, South Asian ethnicity, smoking history, family history of preeclampsia), obstetrical history (nulliparity, history of preeclampsia, short and long interval between pregnancies, gestational age at delivery and birth weight of prior pregnancy >24 weeks, contraceptive method, use of assisted reproductive technologies) and medical history (eg chronic hypertension, DM, renal disease, systemic lupus erythematosus, antiphospholipid syndrome) 
  • Mean arterial pressure (MAP)
  • Uterine artery pulsatility index
  • PlGF
• Baseline test in low-resource settings or by primary care should include maternal risk factors and MAP
• Low-risk women (<1 in 100) may continue with routine prenatal care; high-risk women (≥1 in 100) should be given Aspirin 150 mg nightly from 11-14 weeks of gestation to 36 weeks of gestation, when delivery occurs or when preeclampsia is diagnosed 
• Oral calcium supplementation of 1.5-2.5 g/day in early pregnancy decreases incidence of early- and late-onset preeclampsia and hypertension among all women and also reduces severe preeclamptic complication in pregnant women with low daily calcium intake (<600 mg/day) 
• Evidence is insufficient to recommend vitamins C, E, and D, omega-3 fatty acids, magnesium, folic acid, Heparin, Metformin and statin for reducing the risk of preeclampsia