Hypertension in Pregnancy

A 34-year-old patient, G1P0, at 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

Background

What is preeclampsia?

New onset hypertension with evidence of �organ failure or utero-placental dysfunction

• Typically affects patients after 20 weeks gestation and up to 6 weeks postpartum
• Signs of organ failure must be present on either investigations or physical exam
• Risk factors:
• First pregnancy
• Multiple gestation
• AMA (>35 years-old)
• Diabetes/GDM
• Obesity
• Family history

Background

Systolic BP > 140

or

Diastolic BP > 90

> 20 weeks gestation

< 20 weeks gestation

Organ/utero-placental involvement?

Preeclampsia

Gestational

HTN

Severe HTN

> 160/110 mmHg

YES

NO

Chronic

HTN

Background

Why is preeclampsia an emergency?

It can progress to eclampsia �or HELLP syndrome!

• Eclampsia: onset of seizures that can lead to coma or brain injury, and can be fatal
• HELLP syndrome: onset of Hemolysis, Elevated Liver enzymes, and Low Platelets

Severe hypertension can also lead to hemorrhagic stroke or placental abruption!

History

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

What do you want to know on history?

• What has their BP been like throughout pregnancy? What was their BP like prior to pregnancy?
• Are they currently being treated for hypertension?
• Are they experiencing symptoms of preeclampsia that could suggest organ damage?

Signs of a vascular event (stroke)

History

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

What do you want to know on history?

• Always ask about ABCDs!
• fetal Activity, Bleeding, Contractions, abnormal Discharge/fluid leakage
• Medical history
• Surgical history
• Obstetrical history
• Have they had preeclampsia in previous pregnancies?
• Medications
• Any current BP medications?
• Allergies
• Family history
• History of HTN/PEC* in pregnancy?
• Social history

Exam

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

What should you look for on exam?

• Increased work of breathing?
• Chest pain?
• Palpitations?

Cardio/esp

• RUQ pain/liver palpation
• Symphysis fundal height
• Fetal heart monitor

Abdominal

• Hyperreflexia? Clonus?
• GCS - altered LOC?

Neuro

• Bilateral pitting edema (non-specific finding)

Periphery

• Vitals
• Well or unwell?

General

Investigations

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

What investigations should you order?

• Serial BP monitoring
• BPP and NST
• Labs:
• CBC – Hb, PLT
• ALT
• (urate - not recommended per SOGC guidelines but commonly ordered)
• Cr
• Urinalysis
• Urine PCR
• If suspicious of HELLP: PT/INR, fibrinogen, LDH, bilirubin, haptoglobin, peripheral smear

Management

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

How should you manage patients?

BP can be medically managed with short-acting or long-acting medications, depending on the situation.

Short-acting

• Nifedipine (Adalat) SA 5-10 mg po or Labetalol 10-20 mg IV
• E.g., for patients presenting with acute, severe elevations in BP that need to be managed quickly

Long-acting

• Labetalol 100-400 mg PO bid-tid
• Nifedipine (Adalat) XL 30-60 mg PO daily-bid
• E.g., for patients with chronically elevated BP that needs to be managed throughout pregnancy

Management

​

34-year-old, G1P0, 33+0 weeks, presents with new onset 3/10 headache x2 days.

Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21

How should you manage patients?

Preeclampsia will not resolve until the baby is delivered. Depending on gestational age, you need to decide whether to arrange for immediate delivery or proceed with expectant management.

Diagnosis of preeclampsia

Indications for delivery

• Uncontrolled severe HTN
• Acute kidney injury (creat>150 mmol/L)
• Eclampsia
• HELLP syndrome (PLT<50, INR>2)
• Placental abruption

Remember: if arranging for preterm induction, order prophylactic penicillin G for GBS, MgSO4 for seizure prophylaxis and fetal neuroprotection, and betamethasone for fetal lung development (if <34w0d)

Prevention

Preeclampsia Prevention

• ASA 162 mg po at bedtime (start early, ie between 12-16w, in order to impact the developing placenta, for patients with 1 high risk factor or 2 moderate risk factors)
• calcium (500mg per day or more)
• exercise (30 minutes per day, 5 days per week)

High Risk Factors (Any 1)

• prior preeclampsia
• prior gestational HTN
• chronic HTN
• pre-pregnancy diabetes
• pre-pregnancy BMI >30 kg/m²
• chronic kidney disease
• assisted reproductive therapy
• systemic lupus erythematosus/antiphospholipid antibody syndrome

​

Moderate Risk Factors (Any 2)

• nulliparity
• multifetal pregnancy
• maternal age > 40
• prior IUGR
• prior stillbirth
• prior placental abruption

Note: preeclampsia is also an important risk factor for future development of cardiovascular disease

Practice

CASE 1: A 34-year-old patient, G1P0 at 33w0d presents with new onset 3/10 headache x2 days. Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21.

�The rest of their history is unremarkable. You send them for a preeclampsia workup, which is also unremarkable.

�How do you manage this patient?

Practice

CASE 1: A 34-year-old patient, G1P0 at 33w0d presents with new onset 3/10 headache x2 days. Vitals: 96 bpm, BP 144/92, 36.8°C, RR 21.

�The rest of their history is unremarkable. You send them for a preeclampsia workup, which is also unremarkable.

�How do you manage this patient?

​

​

• Recheck BP
• Manage BP with medications (labetalol 200 mg PO bid) and analgesia (tylenol OK, avoid NSAIDs)
• Encourage home BP monitoring
• Repeat prenatal checkups and PEC labs weekly
• Schedule induction at 38-39 weeks

​

Practice

CASE 2: A 34-year-old patient (G1P0) presents to assessment at 36w2d complaining of significant nausea and a severe headache. Their vitals are: 85 bpm, 161/94 mmHg, RR 18, 36.7°C, SpO₂ 98%. On history/exam, they have RUQ pain on palpation, hyperreflexia, and report seeing flashing lights. Their lab work is as follows:

CBCdiff

WBC 8.1

Hb 118

MCV 87

RDW 14.9

Plt 322

�Chemistry

ALT 156 (H)

Bilirubin 15

Cr 160 (H)

Urinalysis

Appearance yellow/clear

WBC 0

RBC 0

Protein +1

Ketones 0

pH 7.3

�Urine PCR pending (takes 24h to return)

�

Practice

CASE 2: A 34-year-old patient (G1P0) presents to assessment at 36w2d complaining of significant nausea and a severe headache. Their vitals are: 85 bpm, 161/94 mmHg, RR 18, 36.7°C, SpO₂ 98%. On history/exam, they have RUQ pain on palpation, hyperreflexia, and report seeing flashing lights.

​

How do you manage this patient?

​

This patient is presenting with hypertension and evidence of organ damage on symptoms and PEC labs. At 36w2d, the risk of harm to the patient outweighs the risks of preterm delivery.

• Manage with short-acting BP medication (e.g. nifedipine 5-10 mg PO)
• Provide MgSO4 for seizure prophylaxis and initiate delivery (mode can depend on acuity of situation and favourability of cervix)
• Remember empiric penicillin G for GBS if aiming for vaginal route (at 36 weeks, the patient may or may not have had outpatient GBS testing)

​

Practice

CASE 3: 34-year-old patient (G1P0) presents to assessment at 34w6d after being sent over by their OBGYN for very high blood pressure in clinic (198/102 mmHg). They are asymptomatic for symptoms of preeclampsia, and their physical exam is unremarkable. Their lab work is as follows:

CBCdiff

WBC 8.1

Hb 118

MCV 87

RDW 14.9

Plt 322

​

Chemistry

ALT 72 (H)

Bilirubin 15

Cr 90 (H)

Urinalysis

Appearance yellow/clear

WBC 0

RBC 0

Protein 0

Ketones 0

pH 7.3

​

Urine PCR pending (takes 24h to return)

Practice

CASE 3: 34-year-old patient (G1P0) presents to assessment at 34w6d after being sent over by their OBGYN for very high blood pressure in clinic (198/102 mmHg). They are asymptomatic for symptoms of preeclampsia, and their physical exam is unremarkable.

​

How do you manage this patient?

This patient does not show symptoms of preeclampsia on history or exam, and only has very mildly elevated ALT/creat on labs. However, given how severely elevated the BP is, the risk of the patient having a stroke is much higher than the risks of preterm delivery.

• Manage with short-acting BP medication (e.g. nifedipine 5-10mg SA PO, labetalol 10-20 mg IV if does not come down with PO meds)

IF BP CANNOT BE CONTROLLED in spite of using multiple anti-hypertensives: Provide MgSO4 for seizure prophylaxis, consider hydralazine IV infusion, and initiate delivery (mode of delivery depends on acuity of situation and favourability of cervix)

Resources

Resources

Resources

Interested in learning more? Check out these articles!

�SOGC Guidelines: Hypertensive Disorders of Pregnancy (2022)

https://www.jogc.com/article/S1701-2163(22)00234-1/abstract

�Preeclampsia: Narrative review for clinical use

https://ncbi.nlm.nih.gov/pmc/articles/PMC10009735/#:~:text=Preeclampsia%20is%20a%20multisystemic%20disorder,this%20disease%20worldwide%20%5B1%5D

�A literature review and best practice advice for second and third trimester risk stratification, monitoring, and management of pre-eclampsia

https://obgyn.onlinelibrary.wiley.com/doi/10.1002/ijgo.13763

Authors

Claudia Turco

Dr Rahim Janmohamed