NICE 133: Hypertension in Pregnancy— Part 1

Post # 1

This blogpost is Part #1 of summary of latest NICE guideline “NG 133: Hypertension in pregnancy: diagnosis and management released in June 2019. As this is a long guideline, so I will be covering the topic in 2 posts.

This post covers diagnosis / management of hypertension, gestational hypertension, pre-eclampsia (PET) during pregnancy. This guideline has significant changes in recommendations. I have tried my best to extract all the important points.

You must go through the original guideline, which can be downloaded here: NG133

Let me know in comments if I need to add more to the post. 

Thanks

You can access the Part #2 here: NICE: 133 Hypertension in Pregnancy— Part 2

Hypertension in pregnancy: diagnosis and management

Some important numbers (from old guideline)

• Eclampsia rate→ fallen in UK 
• HTN → remains one of leading cause of Maternal Death
• Severe maternal morbidity → 1/3 due to HTN
• ICU admitted with PET/eclampsia: 1 in 20 (5%)
• Stillbirth without anomaly (with PET): 1 in 20 (5%)
• 8-10%→ ALL preterm births due to HTN disorders
• Primigravida→ 1 in 250 (0.4%)→ will deliver before 34wks
• In PET→ Less than 10th centile of birth weight for gestation
•     20-25% preterm births
•     14-19% term birth

Reducing the risk of hypertensive disorders in pregnancy

Symptoms of Pre-eclampsia

• Seek immediate advice if:
• Severe headache
• Vision problem (blurring/flashing)
• Severe pain below ribs
• Vomiting
• Sudden swelling of face, hands or feet

Antiplatelet agents

• Advised to take 75-150 mg aspirin daily from 12 wks until birth of baby

• One high risk factor
• > One moderate risk factor

High Risk	Moderate Risk
H/o HTN in previous pregnancy	First pregnancy
Chronic kidney disease	Age ≥40 yrs
Autoimmune disease (SLE, APS)	Pregnancy interval >10 yrs
Type 1/2 DM	BMI ≥35 kg/m 2 at 1st visit
Chronic HTN	Family history of PET
	Multi-fetal Pregnancy

• DONOT use following with the aim of prevention of hypertensive disorders in pregnancy 

• Nitric oxide donors, progesterone, diuretics, LMWH

• Do not recommend 

• Mg, Folic acid, antioxidants (Vit C & E), fish oils or algal oils, garlic

• No restriction of dietary salt
• Same advice for rest, exercise and work 

Assessment of proteinuria in hypertensive disorders of pregnancy

• Interpret proteinuria measurements in context of full clinical review (symptoms, signs & other tests)
• Use automated reagent-strip reading device for dipstick screening (in secondary care settings)
• Dipstick screening positive (≥1+) → use albumin:creatinine ratio or protein:creatinine ratio to quantify proteinuria
• To quantify proteinuria
• Do not use first morning urine void
• Do not routinely use 24-hour urine collection
• If using protein:creatinine ratio (PCR)

• Threshold for significant proteinuria → 30 mg/mmol 
• If ≥30 mg/mmol + uncertainty about diagnosis → Consider re-testing on new sample alongside clinical review

• If using albumin:creatinine ratio (ACR)

• Diagnostic threshold → 8 mg/mmol
• If ≥8mg/mmol + uncertainty about diagnosis → Consider re-testing on new sample alongside clinical review

• ** both PCR and ACR haven high sensitivity and specificity at thresholds of 30mg/mmol & 8 mg/mmol respectively. Either of these can be used depending on local availability

Management of chronic hypertension in pregnancy

Pre-pregnancy advice

• Offer referral to specialist in hypertensive disorders of pregnancy
• Advice women taking ACE or ARBS or thiazide/thiazide-like diuretics 

• ↑ risk of congenital abnormalities if taken during pregnancy 
• Discuss alternative drugs if planning pregnancy, or if these drugs taken for conditions like renal disease
• If get pregnant→ stop ACE/ ARB (preferably within 2 days of pregnancy notification) & offer alternatives

• Other than ACE/ARB/Thiazide diuretics→ limited evidence for ↑ risks for congenital malformations 

Treatment of Chronic HTN

• Offer advice on→ weight management, exercise, healthy eating, lower salt in diet
• Continue anti-hypertensive treatment if safe or switch to an alternative, unless

• sustained systolic BP is less than <110 mmHg or 
• sustained diastolic BP <70 mmHg or 
• woman has symptomatic hypotension

• Chronic HTN + no t/m → offer antihypertensive t/m if:

• sustained systolic BP ≥140 mmHg or 
• sustained diastolic BP ≥90 mmHg

• Aim for target BP→ 135/85 mmHg 
• Consider

• Labetolol for chronic HTN in pregnancy
• Nefidipine if labetolol not suitable 
• Methyldopa if both labetalol/ nefidipine not suitable

• Offer aspirin 75-150 mg once daily from 12 wks
• Offer placental growth factor (PIGF)-based testing→ to rule out PET b/w 20wks and up to 35 wks (if suspected to develop PET)

Antenatal appointments

• Additional appointments depending on individual needs

• If poorly controlled HTN → weekly
• If well controlled HTN→ every 2 - 4 wks

Timing of birth

Chronic HTN + BP <160/110 mmHg with/ without treatment

• Before 37 wks → do not offer planned early birth before 37wks (unless other medical indications)
• After 37 wks → timing of birth to be agreed b/w mother & senior obstetrician
• If early birth needed offer steroids and magnesium sulfate (if indicated)

Postnatal investigation, monitoring and treatment

Chronic HTN + delivered→ measure BP after birth

• Daily x first 2 days
• At least once b/w day 3 & 5 
• As clinically indicated (if anti-htn t/m changed)

• Aim → keep BP < 140/90 mmHg
• Continue anti-htn t/m if required
• Review anti-htn t/m → 2 wks after birth
• If used methyldopa → stop within 2 days & change to alternative
• Offer Medical Review → 6-8 wks postnatal with GP/specialist 

Management of gestational hypertension

Assessment and treatment

• Full assessment in secondary care settings
• Take account of gestation at presentation
• Additional assessment and follow up needed in

• Nulliparaous Age ≥40 Pregnancy interval >10 yrs
• Family h/o PET
• Multi-fetal pregnancy BMI≥35
• H/o Gestational HTN/PET Pre-existing vascular disease
• Pre-existing kidney disease

Management of pregnancy with gestational hypertension (Ref: NICE)
	Hypertension BP 140/90 — 159/109 mmHg	Severe Hypertension BP ≥160/110 mmHg
Admission to hospital	Not routinely	Admit If BP falls below 160/110 → manage as for HTN
Antihypertensive Drug t/m	Offer if BP remain >140/90	Offer to ALL
Target BP once on t/m	≤135/85 mmHg	≤135/85 mmHg
BP measurement	Once or twice per week until ≤135/85 mmHg	Every 15-30 min untill <160/110 mmHg
Dipstick proteinuria	Once or twice a week	Daily while admitted
Blood tests	FBC, LFT, RFT at presentation & then weekly	FBC, LFT, RFT at presentation & then weekly
PlGF-based testing	ONCE if PET suspicion	ONCE if PET suspicion
Fetal assessment	Offer FHR auscultation each visit USG at diagnosis & if normal → repeat every 2-4 wks (if clinically indicated) CTG only if clinically indicated	Offer FHR auscultation each visit USG at diagnosis & if normal → repeat every 2-4 wks (if clinically indicated) CTG only if clinically indicated

• Offer PIGF-based testing to help rule out PET in women presenting with suspected PET b/w 20 wks and up to 35 wks
• Consider

• Labetolol to treat gestational hypertension
• Nefidipine if labetaolol not suitable
• Methyldopa if both labetolol & nefidipine not suitable
• Choose according to side-effects, risks & woman preference

• Do not offer bed rest as t/m of gestational HTN

Timing of Birth

Gestational HTN BP <160/110 mmHg

• Before 37 wks → do not offer planned early birth before 37wks (unless other medical indications)
• After 37 wks → timing of birth to be agreed b/w mother & senior obstetrician
• If needed early birth offer steroids/ magnesium sulfate (if indicated)

Postnatal investigation, monitoring and treatment

• Gestational HTN + given birth → measure BP after birth

• Daily x first 2 days
• At least once b/w day 3 & 5
• As clinically indicated (if anti-htn t/m changed)

• Gestational HTN + given birth

• Continue anti-htn t/m if required
• Advice that duration of t/m will be similar to antenatal t/m (may be longer)
• Reduce anti-htn t/m if BP falls <130/80 mmHg

• If taken methyldopa → stop within 2 days & change to other drug (if needed)
• Gestational HTN + not taken t/m + given birth → start anti-htn t/m if BP ≥150/100 mmHg
• Write care plan for women being transferred to community & include

• Who will follow up 
• BP check frequency
• Threshold for reducing or stopping t/m
• Indications for referral to primary care for BP review

• Gestational HTN + remain on anti-htn t/m → Offer medical review (GP/ specialist) 2 wks after transfer to community care
• ALL women with gestational HTN → Offer medical review (GP/Specialist) 6-8 wks after birth

Management of pre-eclampsia

Assessing pre-eclampsia

• Assessment to be performed by trained person
• Full clinical assessment at each antenatal appointment 
• Offer admission if ANY of the concerns 

• Sustained systolic BP ≥160 mmHg
• New or persistent
• ↑ creatinine ≥90 μmol/l or ≥1mg/100ml
• ↑ ALT ( >70 IU/l or twice upper limit of N)
• ↓ in platelet count (<150000/μliter)
• Signs of impending eclampsia/ PE
• Suspected fetal compromise
• Any other clinical signs that cause concern (2019)

Risk prediction models

• Consider using fullPIERS or PREP-S for most appropriate place of care/ threshold for interventions

• fullPIERS→ used any time in pregnancy
• PREP-S→ used only up to 34 wks
• Both models do not predict outcomes for babies

• Offer

• Labetalol to treat hypertension with PET
• Nefidipine if labetalol not suitable
• Methyldopa if both labetolol & nefidipine not suitable
• Choose according to pre-existing treatment side-effects, risks & woman preference

Treatment of pre-eclampsia

Management of pregnancy with pre-eclampsia
	Hypertension: BP 140/90 — 159/109 mmHg	Severe Hypertension BP ≥160/110 mmHg
Admission to hospital	Admit if any clinical concerns for mother/baby High risk of adverse events (fullPIERS or PREP-S predicted)	Admit If BP <160/110 mmHg → manage as for HTN
Antihypertensive pharmacological treatment	Offer if BP >140/90 mmHg	Offer to ALL
Target BP once on t/m	≤135/85 mmHg	≤135/85 mmHg
BP measurement	At least every 48 hrs More frequently if admitted	Every 15-30 min until BP <160/110 mmHg , then At least 4 times per day (while inpatient)
Dipstick proteinuria	Only repeat→ if clinically indicated	Only repeat→ if clinically indicated
Blood tests	FBC, LFT, RFT → twice a week	FBC, LFT, RFT → 3 times a week
Fetal assessment	Offer FHR auscultation at each visit USG at diagnosis & if normal → repeat every 2 wks CTG at diagnosis & then only if clinically indicated	Offer FHR auscultation at each visit USG at diagnosis & if normal → repeat every 2 wks CTG at diagnosis & then only if clinically indicated

Timing of Birth

• Record maternal and fetal threshold for planned early birth before 37 wks
• Thresholds could include but not limited to

• Uncontrolled BP in spite of ≥3 classes of drugs
• Maternal pulse O2 <90%
• Progressive deterioration of LFT, RFT, Platelets or hemolysis
• Ongoing neurological feature like serve headache, eclampsia
• Placental abruption
• Reversed end-diastolic flow in umbilical artery doppler/ non-reassuring CTG or stillbirth
• Other features (not listed) may also be considered for early delivery

• Any decision for delivery→ Involve senior obstetrician
• Birth planned → discuss with anaesthetic team / neonatal team (if complications to neonate anticipated)
• If planned early delivery→ corticosteroids + Mg Sulphate (if indicated)

Timing of birth in pre-eclampsia women (NICE)
Weeks of pregnancy	Timing of Birth
Before 34 wks	Continue surveillance unless indications for planned early delivery Offer I/V magnesium sulfate and corticosteroids
From 34 - 36+6 wks	Continue surveillance unless indications for planned early delivery When considering early birth→ take into account fetomaternal wellbeing, risk factors and neonatal unit bed availability Consider I/V magnesium sulfate and corticosteroids
37wks onwards	Initiate birth within 24 hrs

Postnatal investigation, monitoring and treatment (including after discharge from critical care)

Blood pressure

PET + given birth + did not take anti-htn t/m

• Check BP

• Inpatient : at least 4 times per day
• At least once b/w day 3 & 5
• If abnormal on days 3-5 → on alternate days until normal BP

• If BP ≥150/100 mmHg → start anti-htn t/m
• PET + given birth→ ask about severe headache & epigastric pain each time when BP checked

PET+given Birth + took anti-htn t/m→ Continue t/m after birth

• BP <140/90 → Consider reducing t/m
• BP <130/80 → Reduce t/m
• If taken methyldopa→ stop within 2 days of delivery & change to another if necessary
• Offer transfer to community if ALL criteria met

• No pre-eclampsia symptoms
• BP with or without t/m : ≤150/100 mmHg
• Blood tests stable or improving

• Write care plan for women being transferred to community & include ALL

• Who will  provide follow up (medical review if needed)
• BP check frequency
• Threshold for reducing or stopping t/m
• Indications for referral to primary care for BP review
• Self-monitoring for symptoms 

• PET + remain on anti-htn t/m → offer medical review (GP/ specialist) 2 wks after transfer to community care
• ALL women with PET → offer medical review (GP/Specialist) 6-8 wks after birth
• Haematological and biochemicaL monitoring. 

Women with PET with mild or moderate HTN or after step-down from critical care

• Check platelet, transaminases and S.creatinine → 72 hrs after birth or step-down
• If results are normal →Do not repeat
• If results not normal → repeat as clinically indicated till results return to normal
• PET + given birth → do urinary reagent-strip test 6-8 wks after birth
• PET + still proteinuria ≥1+ at 6-8 wks→ Offer further review at 3 months to assess kidney function (GP/Specialist) 
• If abnormal kidney function→ consider referral for specialist kidney assessment

Useful Links

• NICE 133: Hypertension in Pregnancy—Part 2 
• GTG #73 PPROM 
• NICE NG25 Summary
• Starting Point for MRCOG Part 2

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