NICE 133: Hypertension in Pregnancy— Part 2

Post # 2

This blogpost is Part #2 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 planned to cover the topic in 2 posts. 

You can access the Part #1 here: NICE: 133 Hypertension in Pregnancy— Part 1

This Post covers Fetal Monitoring, Intrapartum Care, Management in Critical Care, Post delivery, Drugs, Follow up and Next Pregnancy advice. 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 there are more points to be added. 

Thanks

Hypertension in pregnancy: diagnosis and management

Fetal Monitoring

Chronic HTN

• Carry out USG for fetal growth & amniotic fluid volume assessment plus umbilical artery doppler at 28, 32 and 36 wks
• CTG → only if clinically indicated

Gestational HTN

• Carry out USG for fetal growth & amniotic fluid assessment plus umbilical artery doppler at diagnosis
• If normal → repeat if clinically indicated
• CTG → only of clinically indicated

Pre-eclampsia or severe gestational HTN

• CTG→ at diagnosis
• If conservative management, do ALL at diagnosis

• USG for fetal growth/amniotic fluid assessment
• Umbilical artery doppler
• If normal results→ do not routinely repeat CTG unless clinically indicated
• Repeat CTG → women reports change in fetal movements ; vaginal bleeding; abdominal pain; deterioration in maternal condition

• Repeat USG for fetal growth/amniotic fluid assessment or umblical artery Doppler velocimetry every 2 weeks (subsequent monitoring depend on these scans)
• Write a care plan including ALL
• Timing & nature of future fetal monitoring
• Fetal indications for birth / when to give corticosteroids 
• Plans for discussions with neonatal pediatricians & obstetric anaesthetist

Women who need additional monitoring 

• USG for fetal growth/amniotic fluid assessment plus umbilical artery doppler velocimetry starting at b/w 28 - 30wks (or at least 2wks before previous gestation of onset if earlier than 28 wks) 
• Repeat 4 weeks later in women with previous 
• Severe PET 
• PET resulting in birth before 34 wks
• PET with a baby birth weight <10th centile
• Intrauterine death
• Placental abruption 

• CTG → if clinically indicated

Intrapartum Care : Follow NICE guideline on Intrapartum care

Blood pressure

• During labour → check BP
• HTN → one hourly 
• Severe HTN → every 15-30 min until <160/110 mmHg
• Continue antenatal anti-htn t/m during labour

Haematological and biochemical monitoring

• Same criteria as antenatal to determine the need for test during labour

Care during epidural analgesia 

• Severe PET→ Do not preload with I/V fluid 

Management of second stage of labour

• Controlled HTN → Do not routinely limit the duration 
• HTN not responded to initial t/m→ Consider operative or assisted birth  

Medical management of severe hypertension, severe pre-eclampsia or eclampsia in a Critical Care Setting

Anticonvulsants

• Severe HTN/ PET or previously had eclamptic fit→ Give I/V magnesium sulfate
• Severe PET→ Consider I/V magnesium sulfate if birth planned within 24 hrs
• Consider need for MGSO4 of ≥1 feature of severe PET
• Ongoing or recurring severe headache
• Visual scotomata
• Nausea or vomiting
• Epigastric pain
• Oliguria & severe HTN
• Progressive deterioration in lab blood tests
• Magnesium Sulfate
• Loading dose 4 g I/V over 5-15 min → infusion of 1 g/hr maintained for 24 hrs 
• If fit→ continue infusion 24hrs after last fit
• Do not use diazepam, phenytoin or other anticonvulsants as an alternatives

Antihypertensive

• Severe HTN + critical care during pregnancy or after birth give one of 
• labetalol (oral/I.V) , nefidipine (oral), hydralazine (I.V)
• Severe HTN + critical care → monitor response to t/m
• to ensure BP falls
• to identify adverse effects for mother/baby
• to modify t/m
• First dose of I.V hydralazine (antenatally)→ Consider using up to 500 ml crystalloid fluid before/same time

Corticosteroids

• For fetal lung maturation → If early birth likely within 7 days with PET
• For HELLP t/m→ do not use

Fluid balance and volume expansion

• Do not use in severe PET unless hydralazine used
• Severe PET→ limit fluid to 80 ml/hr unless other ongoing fluid losses

C/S vs IOL →  mode of delivery according to clinical condition + women’s preference 

Clinical Criteria for choice of critical care level
Level 3	Severe pre-eclampsia and needing ventilation
Level 2	Step down from level 3 Severe PET with ANY : eclampsia, HELLP, Haemorrhage, Hyperkalaemia, Severe oliguria, Coagulation support, I/V anti-htn t/m, Initial stabilization of severe HTN, Cardiac failure evidence, Abnormal neurology
Level 1	Pre-eclampsia with hypertension Ongoing conservative antenatal management of severe preterm HTN Step-down t/m after birth

Antihypertensive treatment during the postnatal period, including during breastfeeding 

• HTN + wish to breast feed
• Advise: t/m can be adapted / anti-htn drugs do not prevent them from breastfeeding 
• Explain: anti-htn meds can pass into breast milk 
• Most drugs very low levels in breast milk; unlikely to harm the baby
• Make decisions on treatment with women preference 
• Consider monitoring BP of babies→ especially who are born preterm or have symptoms of low BP
• While discharging women home → advice to monitor babies for drowsiness, lethargy, pallor, cold peripheries or poor feeding
• Offer → Enalapril during postnatal time with appropriate monitoring of RFT & maternal serum potassium
• Black African or Caribbean family origin with HTN in postnatal 
• Consider t/m with nefidipine or
• Amlodipine if woman used it successfully before to control BP
• If BP not controlled with one medicine→ consider combination of nefidipine (or amlodipine) and enalapril
• If not tolerated or ineffective consider either
• Adding atenolol or labetalol to combination treatment or
• Swapping 1 medicine for atenolol or labetolol
• Use medicines which are taken once daily when possible in postnatal period
• If possible→ avoid using diuretics or ARBs in breastfeeding/ expressing milk
• If not breastfeeding→ treat in line with national guidance on “hypertension in adults”

Advice and follow-up at transfer to community care

Risk of recurrence of hypertensive disorders of pregnancy

Overall risk of recurrence → 1 in 5 (20%)

Likelihood of recurrence of hypertensive disorders of pregnancy
Prevalence of hypertensive disorder in a future pregnancy	Any HTN in pregnancy	Pre-eclampsia	Gestational HTN
Any HTN	21% (1 in 5)	20% (1 in 5)	22% (1 in5)
Pre-eclampsia	14% (1 in 7)	16% (1 in 6) If birth at 28-34wks:33% (1:3) at 34-37 wks: 23% (1:4)	7% (1 in 14)
Gestational HTN	9% (1:11)	6-12% (1 in 8)	11-15% (1 in 7)
Chronic Hypertension	N/A	2% (1 in 50)	3% (1 in 34)

Long-term risk of cardiovascular disease

Cardiovascular risk in women who have had a hypertensive disorder of pregnancy
Risk of future cardiovascular disease	Any HTN in Pregnancy	Pre-eclampsia	Getstational HTN	Chronic HTN
Major adverse cardiovascular event	↑ up to 2 X	↑ up to 1.5-3 X	↑ up to 1.5-3 X	↑ up to 1.7 X
Cardiovascular mortality	↑ up to 2X	↑ up to 2X	No data	No data
Stroke	↑ up to 1.5 X	↑ up to 2-3 X	May be ↑	↑ up to 1.8 X
Hypertension	↑ up to 2-4 X	↑ up to 2-5 x	↑ up to 2-4 X	N/A

• Advised → discuss how to reduce the risk of cardiovascular disease with GP/Specialist
• Avoid smoking
• Maintain healthy weight/ lifestyle
• Women with PET or HTN leading to early birth → pre-pregnancy counseling to discuss risks & possible recurrences 
• Keep BMI within healthy range
• Likelihood of recurrence increases with pregnancy interval >10 yrs
• H/o PET with no proteinuria→ tell at postnatal review→ relative risk of end-stage kidney disease is increased but absolute risk is low & no further followup needed
• Do not routinely perform thrombophillia screening in women who had PET

Useful Links

• NICE 133: Hypertension in Pregnancy—Part 1 
• GTG #73 PPROM 
• NICE NG25 Summary
• Starting Point for MRCOG Part 2