Pregnancy Part 2 – HTN – SOGC 2014

Ominous symptoms: RUQ pain, H/A, Visual disturbances

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Dx

1) Pre-existing (chronic) hypertension: HTN (>140/90) that develops either pre-pregnancy or at < 20+0 weeks’ gestation

• Essential HTN ↑ risk of gestational HTN, placenta abruption, IUGR, IUFD
• Performed during early pregnancy: (if not previously documented): serum creatinine, fasting blood glucose, serum potassium, and U/A, and EKG.
• With comorbid condition(s): pre-gestational type I or II diabetes mellitus or kidney disease (↑ CV risk)
• With evidence of preeclampsia = 2) superimposed preeclampsia
  • is defined by the development of one or more of the following at ≥ 20 weeks:
    ● resistant hypertension, or
    ● new or worsening proteinuria, or
    ● one or more adverse conditions,* or
    ● one or more severe complications.*

3) Gestational hypertension

• hypertension that develops for the first time at ≥ 20+0 weeks’ gestation.

4) Preeclampsia

• Gestational hypertension with one or more of the following: May arise de novo
  ● new proteinuria, or
  ● one or more adverse conditions,* or
  ● one or more severe complications.*

5) Severe preeclampsia: preeclampsia with >1 complications.

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Transient hypertensive effect: Elevated BP may be due to environmental stimuli, e.g., the pain of labour. HTN not confirmed at subsequent measurement
White-coat hypertensive effect: This is defined as BP >140/90 in the office, but consistently normal outside of the office (< 135/85 mmHg)
Masked hypertensive effect: This is defined as BP that is consistently <140/90 in the office, but≥ 135/85 outside of the office

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Adverse conditions (↑ severe c/i) and severe complications (warrant delivery) of preeclampsia

CNS:

• Headache/visual symptoms
• Eclampsia, PRES ( posterior reversible leukoencephalopathy syndrome), Cortical blindness or retinal detachment, Glasgow coma scale < 13, hemorhagic Stroke (50% of deaths), TIA, or RIND (reversible ischemic neurological deficit (< 48 hr))

CV:

• Chest pain/dyspnea, Oxygen saturation < 97%
• Uncontrolled severe hypertension (over a period of 12 h despite use of three antihypertensive agents), Oxygen saturation < 90%, need for ≥ 50% oxygen for > 1 h, intubation (other than for Caesarean section), pulmonary edema, Positive inotropic support, Myocardial ischemia or infarction

Haematological:

• Elevated WBC / INR / aPTT / ; low platelet
• Platelet count < 50 × 109, Transfusion of any blood product

Renal:

• Elevated serum creatinine / uric acid
• AKI (creatinine > 150 µM with no prior renal disease), New indication for dialysis

Hepatic

• N/V, RUQ or epigastric pain, Elevated serum AST, ALT, LDH, or bilirubin, Low plasma albumin
• Hepatic dysfunction (INR > 2 in absence of DIC or warfarin), DIC, Hepatic haematoma or rupture, HELLP syndrome (Tx with FFP infusion / plasma exchange)

Feto-placental:

• Abnormal FHR, IUGR, Oligohydramnios, Absent or reversed end-diastolic flow by Doppler velocimetry
• Abruption with evidence of maternal or fetal compromise, Reverse ductus venous A wave, Stillbirth (IUFD)

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 Risk factors Gestation HTN

1. Maternal:
   • primigravida, 1st conception with a new partner, PMHx/FHx of gestational HTN, extremes of maternal age <18 or >35
   • DM, chronic HTN, renal insufficiency, antiphospholipid syndrom
2. Fetal:
   • IUGR or oligohydramnios, GTN, multiple gestation, fetal hydrops
   • Previous stillbirth or IUFD

Risk factors Preeclampsia

1. Maternal:
   • Nulliparity, PMHx / FHx of preeclampsia, age >40 or <18, high BMI
   • chronic HTN/renal dz, DM (pregestational or gestational), antiphospholipid syndrome / inherited thrombophilia, vascular / connective tissue dz
2. Fetal:
   • Hydrops fetalis, unexplained fetal growth restriction, placenta abruption,

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Hx:

• Hepatic: Epigastric or RUQ pain, severe N/V,
• CNS: visual disturbances – blurring / scotoma, presence / severity of H/A, tremulousness, irritability, somnolence
• Hematologic: bleeding
• Renal: u/o & color
• Non-dependent edema – hands & face
• Fetal movement

O/E:

• Body weight & non-dependent edema
• CNA: hyperreflexia, visual field
• Hematology: petechiae
• Fetal heart tracing – NST

Ix:

• U/S for growth & biophysical profile, umbilical artery doppler flow studies (part of antenatal fetal surveillance)
• Hb, plt, blood film, PTT, INR, fibrinogen, d-dimer
• ALT, AST, LDH, bilirubin, uric acid, creatinine
• U/A – (proteinuria) 24 hr urine for total protein and creatine clearance
• Definitive testing for proteinuria (by urinary protein:creatinine ratio or 24-hour urine collection) if suspicious of  preeclampsia, including:
  • ≥ 1+ dipstick proteinuria
  • in women with hypertension and rising BP
  • in women with normal BP, but S/Sx suggestive of preeclampsia.

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Tx HTN:

Low Risk Pt (based on risk factors):

• Dietary salt restriction during pregnancy (I-D), calorie restriction during pregnancy for overweight women (I-D), low-dose acetylsalicylic acid (I-E), vitamins C and E (based on current evidence) (I-E), and thiazide diuretics (I-E) are not recommended.
• For preeclampsia prevention among low-risk women with low dietary calcium intake (<600 mg/d), oral calcium supplementation of at least 1g/d is recommended
• smoking cessation for prevention of low birthweight and preterm birth.
• periconceptual use of a folate-containing multivitamin for prevention of neural tube defects(I-A), and
• exercise for maintenance of fitness(I-A), abstention from alcohol for prevention of fetal alcohol effects (II-2E),