Hypertensive Disorders in Pregnancy

Question 1

Definitions;

1. Pregnancy-induced HTN
2. Gestational HTN
3. Pre-eclampsia
4. Primary/Secondary HTN

Answer 1

1. BP>140/90 after 20w
2. New HTN after 20w without proteinuria
3. HTN and proteinuria(>0.3g/24h)
4. BP>140/90 before pregnancy/before 20w

Question 2

Classifications:

1. HTN
2. Pre-eclampsia

Answer 2

1. a) Mild: 140/90-149/99
   b) Moderate: 150/100-159/109
   c) Severe: 160/110+
2. a) Mild: Mild/mod HTN+proteinuria
   b) Moderate: Severe HTN+Proteinuria, X maternal complications
   c) Severe: any HTN <34w OR with maternal complications + Proteinuria

Question 3

PRE-ECLAMPSIA

Epidemiology

Answer 3

• 6% nulliparous

- 15% recurrence rate, up to 50% if severe pre-eclampsia before 28w

Question 4

Risk f

Answer 4

1. Prev Hx
2. FHx
3. Microvasc disease ie diabetes, chronic HTN, CKD, sickle cell disease, autoimmune ie antiphospholipid syndrome
4. Nulliparity
5. Twin pregnancy
6. Obesity
7. Extremes of age, esp >40y
8. Long interpregnancy interval

Question 5

Clinical features:

1. History
2. Examination

Answer 5

1. Usually asymptomatic. at late stages: headache, drowsiness, nausea/vomiting, epigastric pain, visual disturbances
2. HTN first sign usually. Sudden, non-postural oedema, epigastric tenderness, urine dipstick(≥2+)

Question 6

Maternal Complications

Answer 6

1. Eclampsia(.05% pregnancies)
2. HELLP
3. Renal failure
4. Cerebrovascular haemorrhage
5. Pulmonary oedema
6. DIC
7. Liver failure

Question 7

Fetal Complications

Answer 7

1. If <34w, Preterm birth(up to 10% preterm deliveries), IUGR
2. Any gestation, increased risk of placental abruption.

Question 8

Investigations:

1. Confirming Dx
2. Monitoring for maternal complications
3. Monitoring for fetal complications

Answer 8

1. 2 BP measurements 4h apart. If dipstick positive, urine culture to exclude infection. PCR ≥30mg/nmol. repeat testing as proteinuria can be absent in early disease.
2. FBC: rapid fall in platelets → HELLP. rise in Hb. LFTs: rise in ALT; bilirubin(haemolysis). Lactate: increases. U&;E’s: rising creatinine, uric acid
3. USS, Umbilical artery Doppler and if abn, CTG.

Question 9

Screening

Answer 9

1. High risk(age >40, nulliparity, pregnancy interval>10y, FHx, PMH, BMI ≥ 30, pre-existing vasc disease, pre-existing renal disease, multiple pregnancy) get regular BP and urinalysis, each antenatal visit.
   - HTN w single diastolic measurement of 110/2 measurements of 90,4h apart and/or 1+ preoteinuria require escelation in surveillance.
2. Uterine artery Doppler at 11-13+6w, BP, biochemical markers to assess risk.
3. Biochemical markers:
   a) Oxidative response
   - uric acid, urinary kallikrenin, fibronectin

b) 1st trimester
- PAPP-A, inhibin A, Corticotrophin-releasing hormone, activin

c) 2nd trimester
- β-HCG, αFP, unconjugated estriol

*If at risk, Aspirin 75mg from 12w until birth

Question 10

Management:

Assessment in Day Assessment Unit

Answer 10

1. Mild/moderate HTN + X proteinuria, BP+urinalysis every 2w and USS every 2-4w.
2. Admit if: proteinuria ≥2+ although no HTN. Discharge if PCR not significant. Definitely admit if symptoms, proteinuria≥2+, Severe HTN, suspected fetal compromise.
3. if 1+ proteinuria, quantify and review 2d later.

Question 11

Drugs

Answer 11

1. Antihypertensives:
   - if ≥150/110.
   - Oral nifedipine than IV labetalol. Aim 140/90
   - Benefits: increase mom’s safety, reduce hospitalisation, allow prolongation of pregnancy
2. Magnesium sulphate:
   - IV loading then IVI
   - usually followed by delivery.
   - Monitor urine output, resp rate, 02 sats, reflexes
3. Steroids:
   - if gestation <34w

Question 12

Timing of delivery:

• ≥1 fetal/maternal complications likely within 2w of proteinuria onset.
  1. Gestational HTN wout fetal compromise.
  2. Mild pre-eclampsia.
  3. Moderate/severe
  4. Severe w complications/fetal distress

Answer 12

1. Monitor, IOL at 40w if Tx req.
2. by 37w
3. delivery if 34-36w. <34w, conservative Mx with intensive maternal and fetal surveillance. Clinical deterioration prompts delivery.
4. DELIVER!!!!!!!

Question 13

Conduct of delivery

Answer 13

1. <34w, C section
2. > 34w, IOL w prostaglandins.
3. Epidural reduces BP
4. Continuous CTG
5. BP and fluid balance
6. Antihypertensives
7. Avoid maternal pushing at 160/110
8. Oxytocin over ergometrine at 3rd stage

Question 14

Postnatal care

Answer 14

1. LFT, platelets, renal fn.
2. Fluid balance: 80ml/h + losses
3. CVP if urine output persistently low; frusemide if CVP high, fluids if low. if normal but persistent oliguria, may need dialysis w rising K+.
4. BP maintained at 140/90. Tx w beta blocker(1st line) OR nifedipine/ACE-i
5. Long term: GP and community midwives. if persistent proteinuria/HTN at 6w, refer to renal/HTN clinic.

Question 15

PRE-EXISTING HTN IN PREGNANCY

Epidemiology

Answer 15

about 5% pregnancies

Question 16

Risk f

Answer 16

Age, high BMI, FHx, COCP.

Predisposes to HTN needing Tx later in life.

Question 17

Aetiology

Answer 17

Primary: Idiopathic. Secondary: Obesity, diabetes, Renal disease. Rare: Phaeochromocytoma, coarctation of aorta, Cushing’s, cardiac disease.

Question 18

Clinical features

Answer 18

usually asymptomatic. otherwise, fundal changes, renal bruits, radiofemoral delay.

Question 19

Complications

Answer 19

Worsening HTN, pre-eclampsia(6x). perinatal mortality only marginal increase in absence of these.

Question 20

Investigations:

1. Identifying secondary HTN
2. Look for coexistent disease
3. Identify pre-eclampsia

Answer 20

1. Phaeochromocytoma: exclude w two 24h urine collections for VMA
2. Renal fn. and renal US
3. Quantify proteinuria at booking and uric acid lvl for comparisons later.

Question 21

Management:

1. HTN
2. Risk of pre-eclampsia

Answer 21

1. Stop ACE-i. Labetalol(1st line), Nifedipine(2nd line)

2. Treat as high-risk. More freq antenatal visits. Screen w umbilical artery Doppler. Low-dose aspirin