9) Maternal Medicine: Hypertension/PET

Question 1

Incidence of hypertensive disorders in pregnancy (hypertension, PET, severe PET, eclampsia)

Answer 1

Hypertension: 8-10%
PET: 5%
Severe PET: 0.5%
Eclampsia : 1/4000

Question 2

Major and minor risk factors for PET

Answer 2

MAJOR:

• Hypertension
• Previous PIH/PET
• Chronic kidney disease
• T1 or T2 DM
• Autoimmune disorders

MINOR:

• Age > 40
• BMI > 35
• First pregnancy
• Inter-pregnancy interval > 10 years
• Multiple pregnancy
• FHx PET

Question 3

When to admit?

Answer 3

Gestational hypertension: Only if severe (>16 0/110)

PET:

• Sustained systolic BP >160
• Severe PET (>160/110 or symptoms or fetal concerns)
• Signs of impending eclampsia
• Signs of impending pulmonary oedema
• Abnormal bloods (Cr >90, ALT>70, Plts <150)
• Fetal compromise

Question 4

Target blood pressures

Answer 4

On treatment 135/85. Treat if persistently >140/90. (All types).

Question 5

How often to monitor blood pressure?

Answer 5

Chronic hypertension: Weekly if poor control, 2-4 weekly if good control.

Gestational hypertension: 1-2 x per week if mild/moderate, if severe then every 15-30 minutes until <160/110 and then at least QDS whilst inpatient.

PET: Mild/moderate - at least every 48 hours. Severe - every 15-30 minutes until <160/110 and then QDS whilst inpatient.

Question 6

How often to check urine?

Answer 6

Chronic hypertension: At each review

Gestational hypertension: Mild/moderate: 1-2 x per week. Severe then daily whilst admitted.

PET: Don’t repeat once established.

Question 7

How often to do blood tests?

Answer 7

Chronic hypertension: Don’t need.
Gestational hypertension: Weekly (any severity).
PET: 2x per week if mild/moderate. 3 x per week if severe.

Question 8

When to do growth scans?

Answer 8

Chronic hypertension: 28,32,36 weeks.
Gestational hypertension: Mild/moderate - every 2-4 weeks. Severe - every 2 weeks.
PET: Every 2 weeks.

Question 9

What tests can be done if PET suspected in someone with chronic hypertension or gestational hypertension?

Answer 9

PIGF based testing 20-35 weeks. (Abnormally low in PET)

Question 10

When to deliver?

Answer 10

Chronic/gestational hypertensives: After 37 weeks provided BP <160/110 unless another indication.

PET: Before 37 weeks if indication (including inability to control BP despite 3 or more classes of drugs in appropriate doses). After 37 weeks plan for delivery within 24-48 hours.

Question 11

Postnatal BP measurements

Answer 11

Chronic hypertension: Daily D1/D2 and at least once D3-D5.
Review at 2/52 and 6-8/52.

Gestational hypertension:
Same.

PET:
QDS whilst inpatient.
If not medicated then once D3-D5 and alternate days after that if abnormal.
If medicated then every 1-2 days for 2 weeks until off treatment.

Question 12

When to reduce blood pressure medication postnatal?

Answer 12

If BP <130/80 (consider if less than 140/90)

Question 13

When can a PET patient be transferred to community?

Answer 13

No symptoms
BP <150/100
Bloods stable (measured 48-72h PN)

Question 14

What to do if proteinuria still present at 6-8/52 check?

Answer 14

Repeat at 3/12 and if still present refer to renal

Question 15

How often should BP be checked in labour?

Answer 15

Hourly (and every 15-30 minutes if >160/110)

Question 16

WHen should MgSO4 be used for hypertension?

Answer 16

• If eclampsia seizure
• Severe PET and delivery planned for 24h
• Consider if symptomatic/abnormal bloods

Question 17

Dosing of MgSO4

Answer 17

4 gram bolus over 5-15 minutes then 1g/h for 24h (or until 24h seizure free)
If recurrent fits then further bolus 2-4g

Question 18

Fluid balance precautions in PET

Answer 18

80ml/h in severe PET unless ongoing loss

Consider 500mL crystalloid only if using IV hydralazine.

Question 19

What do the three levels of care mean?

Answer 19

Level 3 - requiring ventilation
Level 2 - everything else! (AOCU)
Level 1 - conservative management (ward)

Question 20

Postnatal antihypertensives

Answer 20

(1) Enalapril
(2) Afro-Caribbean: Nifedipine or amlodipine

If single agent is ineffective:

• Enalapril + nifedipine/amlodipine
• Add labetalol/atenolol

Question 21

Overall risk of any type of hypertension in future having had any type of hypertension in pregnancy

Answer 21

20%

Question 22

I have had PET this pregnancy, what are my risks in the future?

Answer 22

PET but no early delivery: Risk of PET 16%
PET delivery 34-37w: Risk of PET 23%
PET delivery 28-34w: Risk of PET 33%
PET delivery <28w: Risk of PET 55%

Risk of gestational hypertension: 6-12%
Risk of chronic hypertension: 2%

Question 23

I have had PIH this pregnancy, what are my risks in the future?

Answer 23

PET: 7%
PIH: 14%
Chronic hypertension: 3%

Question 24

What cardiovascular risks in the future for someone with PET/PIH?

Answer 24

2 x increased risk of major cardiovascular adverse event, cardiovascular mortality, stroke and hypertension.

Question 25

Percentage of severe PET complicated by HELLP

Answer 25

20%

Question 26

Percentage of HELLP without proteinuria/hypertension

Answer 26

15%

Question 27

Percentage of HELLP with abruption

Answer 27

15%

Question 28

Timing of HELLP onset

Answer 28

15% 2nd trimester, 50% third trimester, remainder postnatal

Question 29

Blood tests to detect haemolysis

Answer 29

Abnormal peripheral blood film with fragmented red cells or increased reticulocyte count.
Raised unconjugated bilirubin.
Low haptoglobin.
Increased LDH.

Question 30

What percentage of cases of PET/PIH can be predicted by maternal history?

Answer 30

47% PET

35% PIH

Question 31

Most significant risk factor for PET

Answer 31

Maternal age

Question 32

Benefits of aspirin on PET

Answer 32

17% risk reduction in developing PET.
RR 0.6 PET and 0.3 severe PET.
NNT 19.

Reduced risks of PTL, foetal or neonatal death, FGR.

Question 33

Daily recommended calcium intake

Answer 33

1000mg/day

Question 34

Recommended calcium supplementation

Answer 34

1.5-2g per day from 20 weeks in populations where calcium intake is low.