HTN in pregnancy

Question 1

How common in HTN in pregnancy ?

Answer 1

10-15% of pregnancies are affected (very common)

Question 2

What percentage of primigravid (1st pregnancy) women are affected by pre-eclampsia (PET)?

Answer 2

• 10% are affected by mild PET
• 1% are affected by severe PET

Question 3

What is the commonest cause of elective (medically induced) prematurity i.e. needing to have the baby born before premature due to risks to mother or baby?

Answer 3

PET

Question 4

Describe the changes to BP during pregnancy and why they occur

Answer 4

• BP initially falls during early pregnancy reaching its lowest point at 22-24 weeks. After this is steadily rises
• This is because pregnancy causes vasodilation which results in a decreased SVR, there is an increase in CO but it is outmatched.

Note BP = SVR x CO

Question 5

Following delivery of the baby what happens to the mothers BP ?

Answer 5

• It falls initially but then rises and peaks at days 3/4 postnatally
• By 6 weeks postnatally BP should be back to normal (easy to remember because puerperium i.e. when things are returning to normal only lasts 6 weeks)

Question 6

How is HTN diagnosed in pregnancy ?

Answer 6

1. By a BP of ≥ 140/90 on 2 occasions, followed by ambulatory BP monitoring or home BP monitoring if they cant use ABPM to confirm diagnosis
2. OR by BP > 160/110 once, if severe BP (i.e. > 160/110) then consider starting on anti-HTN immediately without waiting for ABPM or HBPM

Question 7

State the classifications for the severity of HTN

Answer 7

• Mild HTN = 140/90 → 149/99
• Moderate HTN = 150/100 → 159/109
• Severe HTN = ≥ 160/110

Question 8

What are the 3 HTN disorders in pregnancy ?

Answer 8

• Pre-exisiting (chronic/essential) HTN
• Pregnancy induced HTN (gestational)
• Pre-eclampsia (PET)

Question 9

Define what pre-existing (chronic/essential) HTN is in pregnancy

Answer 9

It is HTN present at booking or < 20 weeks (basically they had it prior to pregnancy because BP should be decreasing during this part of pregnancy)

Question 10

Define what pregnancy induced HTN is

Answer 10

New HTN presenting > 20 weeks into pregnancy without any significant proteinuria

Question 11

What secondary causes should you consider for pre-exisiting (chronic/essential) HTN in pregnancy ?

Answer 11

Renal, cardiac, cushings, conn’s, phaechromocytoma

Question 12

When is pre-exisiting HTN in pregnancy often diagnosed ?

Answer 12

• It is often actually diagnosed prior to pregnancy

Note if it doesn’t resolve within 3 months post-delivery then can be retrospectively diagnosed as pre-exisiting HTN

Question 13

What are the risks of HTN in pregnancy ?

Answer 13

• PET
• IUGR
• Placental abruption

Question 14

What are the characteristic features of pregnancy induced HTN ?

Answer 14

Occurs during the second half of pregnancy and it resolves within 6/52 post delivery

Question 15

The rate of recurrence of pregnancy induced HTN is high in subsequent pregnnacies - T or F?

Answer 15

True

Question 16

Define what PET is

Answer 16

It is a pregnancy specific multi-system disorder with unpredictable, variable & widespread maniifestations

Question 17

What are the characteristic features of PET ?

Answer 17

• New HTN after 20 weeks + Significant proteinuria
• +/- oedema as it is non-specific

Question 18

Describe the pathogenesis of PET

Answer 18

• The primary defect is failure of trophoblastic invasion of spinal arteries

Spinal arteries proide blood to the interoplacental junction (from mother), normally you get cytotrophoblastic invasion which destroys some of the tunica smooth muscle allowing spiral arteries to open up and become high capacity, low resistance vessels

But in PET you get lack of cytotrophoblastic invasion ==> spiral arteries fail to adapt into high capacity low resistance vessels ==> they are narrower causing higher pressure & decreased flow to placenta ==> widespread endothelial damage & dysfunction ==> endothelial activation occurs causing increased capillary permeability, expression of CAM, prothrombotic factors, platelet aggregation and vasoconstriction

Question 19

What are the symptoms of PET ?

Answer 19

• Headache
• Visual disturbance
• Epigastric / RUQ pain
• Nausea / vomiting
• Rapidly progressive oedema

Question 20

What are the signs of PET ?

Answer 20

• HTN
• Proteinuria
• Oedema
• Abdominal tenderness (RUQ/epigastric region)
• Disorientation
• Small for Gestational Age (SGA) Fetus
• Intra uterine fetal death
• Hyper-reflexia / involuntary movements / clonus

Question 21

How is significant proteinuria diagnosed in pregnancy ?

Answer 21

1. Use reagent strip reading or spot urinary protein:creatinine ration
2. If strip used & 1+ of protein then use spot urinary protein:creatinine ratio

Diagnose significant proteinuria if ≥ 0.3g/l or ≥0.3g/24hr (second is only if a 24hr urine collection is used which is a worse test)

Question 22

List the potential complications of PET

Answer 22

• Fetal: prematurity, intrauterine growth retardation, IUD, placental abruption
• CNS: Eclampsia, HTN encephalopathy, intracranial haemorrhage, cerebral oedema, cortical blindness, CN palsy
• Cardiac failure
• Hepatic rupture
• Acute renal failure
• Multi-organ failure
• HELLP syndrome
• DIC
• Pulmonary oedema ==> ARDS
• Pulmonary embolism

Question 23

What is HELLP syndrome and what is the management of it ?

Answer 23

It consists of:

• Haemolysis = destruction of RBC
• Elevated Liver enzymes
• Low Platelets

The signs and symptoms are pretty much the same as PET

It carries with it significant mortality (up to 30%), definitive management is to deliver the baby, however if delivery can be held off then corticosteroids for lung maturation and MgS04 for neuroprotection can be given for the baby

Question 24

What investigations in antenatal care should be carried out for a pregnant women with HTN or PET?

Answer 24

• Bloods - FBC, Us&Es, LFT’s. serum urate, coagulation screen
• Urine PCR (protein:creatinine ratio)
• CTG
• U/S - fetal biometry (measuring size), AFI, doppler studies

Question 25

Following initial investigations assessment of HTN or PET what follow-up investigations are required for someone with mild/moderate HTN?

Answer 25

1. Carry out U/S: fetal biometry, AFI and doppler studies (umbilical artery doppler velocimetry) between weeks 28-30 and 32-34 2. If normal don't repeat after 34 weeks. 3. Only carry out CTG if fetal activity is abnormal e.g. reduced

Question 26

Following initial investigations assessment of HTN or PET what follow-up investigations are required for someone with severe HTN or PET ?

Answer 26

* Don't repeat CTG \> weekly and don't repeat U/S fetal biometry, AFI or doppler studies \> every 2 weeks (so think this is saying do is weekly and every 2 weeks roughly)

Question 27

What iextra nvestigations should someone at high risk of PET receive during their pregnancy ?

Answer 27

Carry out U/S - fetal biometry, AFI & doppler studies between 28-30 weeks & repeating 4 weeks later

Question 28

List the moderate and high risk factors for PET and then state when and what prophylactic treatment can be given

Answer 28

Women with ≥ 2 moderate or ≥ 1 high risk factor for PET should receive 75mg of aspirin from 12 weeks until birth

Question 29

What scan can be done to help predict development of PET in a pregnancy and when is it done during antenatal care ?

Answer 29

* A maternal uterine artery doppler done between 20-24 weeks * If notching seen on scan then greater risk of PET

Question 30

When should a pregnant women be referred up to the antenatal day care unit (AN DCU)?

Answer 30

* BP ≥ 140/90 * (++) proteinuria * oedema * symptoms - esp persistent headache

Question 31

After being referred up to the AN DCU when should a pregnant women be admitted ?

Answer 31

1. BP \>170/110 OR \>140/90 with (++) proteinuria 2. Significant symptoms - headache / visual disturbance / abdominal pain 3. Abnormal biochemistry 4. Significant proteinuria - \>300mg / 24h 5. Need for antihypertensive therapy 6. Signs of fetal compromise

Question 32

When a pregnant women is admitted after being assessed at the AN DCU what assessements/monitoring should be carried out ?

Answer 32

1. Blood Pressure - 4 hourly 2. Urinalysis - daily 3. Input / output fluid balance chart 4. Urine PCR - if proteinuria on urinalysis 5. Bloods - FBC, U&Es, Urate, LFTs. Minimum X2 per week

Question 33

When should treatment of HTN in pregnancy be provided and what is the BP targets for treatment ?

Answer 33

* Treat if BP \> 150/100. * A BP \> 170/110 requires immediate treatment Aim for BP controlled between 140-50/90-100

Question 34

What is the treatment of HTN in pregnancy (also the management of PET) ?

Answer 34

* 1st line = Labetalol (avoid in asthma) * 2nd line = nifedipine (can give bad headaches) or methyldopa * 3rd line = Hydralazine or doxazocin

Question 35

In the treatment of HTN in pregnancy what drugs should you avoid/stop ?

Answer 35

Any ACEi/ARBs

Question 36

What should you be careful of when using methyldopa in pregnancy for HTN ?

Answer 36

It can exacerbate depression so be careful in women with mental illness history

Question 37

Of the hypertensive drugs used in pregnancy which one is not recommended in breastfeeding women?

Answer 37

Doxasocin

Question 38

Go over these points for considering when to deliver when a women develops PET

Answer 38

* Only cure for PET is birth * Consider expectant management if the baby is pre-term * Steroids for fetal lung maturation may be needed * Most mothers delier within 2wks of diagnosis of PET

Question 39

What are the indications for birth in PET ?

Answer 39

1. Term gestation 2. Inability to control BP 3. Rapidly deteriorating biochemistry / haematology 4. Eclampsia 5. Other Crisis 6. Fetal Compromise - abnormal Ultrasound or CTG

Question 40

Define what eclampsia is

Answer 40

This is tonic clonic (grand mal) seizures occurring with features of PET

Question 41

Is it common for women to develop the seizures of eclampsia before onset of HTN/proteinuria ?

Answer 41

Yes 1/3rd will have a seizure before the development of HTN/proteinuria

Question 42

What age group of women is eclampsia more common in ?

Answer 42

Teenagers

Question 43

Define what severe PET is

Answer 43

This is BP \> 160/110 + proteinuria OR BP \> 140/90 + proteinuria plus one more of: * Seizures * Visual disturbances * Clonus * Headache or epigastric pain * Papilloedema * Liver tenderness or HELLP

Question 44

Outline the management of severe PET/eclampsia

Answer 44

1. Control BP 2. Stop / Prevent Seizures 3. Fluid Balance 4. Delivery

Question 45

How is the BP controlled in servere PET/eclampsia ?

Answer 45

1st line = IV labetalol + IV hydralazine

Question 46

How do you stop/prevent the seizures in severe PET/eclampsia ?

Answer 46

* 1st line = IV MgSO4 * 2nd line = if further seizures give more IV MgSO4 * 3rd line = IV diazepam

Question 47

How is fluid balance controlled in severe PET/eclampsia ?

Answer 47

* **Fluid restrict to 80ml/hr** Note - main cause of maternal death is pulmonary oedema (leading to acute resp distress) and oliguria which occurs in 30% of cases doesn't need intervention

Question 48

What are the signs/symptoms of acute resp distress syndrome ?

Answer 48

* Laboured rapid breathing * Mental confusion * Fatigue/ weakness * Fast pulse * Low BP

Question 49

What is the delivery treatment of severe PET/eclampsia ?

Answer 49

* Aim for vaginal birth if possible * Control BP * Give Epidural anaesthesia * Continuous electronic fetal monitoring * Avoid ergometrine - due to its hypertensive effect * Caution with IV fluids