Hypertension (high BP) in pregnancy

Systolic BP 140mmHg or more and/or diastolic BP 90mmHg or more

• Confirm by repeated readings over several hours
• Re-check with manual sphygmomanometer if available

Types of hypertension (high BP) in pregnancy

• Chronic hypertension
• Known to have high BP before pregnancy
• OR high BP recorded in first 20 weeks of pregnancy
• Pregnancy-induced hypertension
  
• High BP first recorded when more than 20 weeks pregnant
• Preeclampsia
• More than 20 weeks pregnant
• High BP AND one OR more other signs or symptoms — Table 2.15
• If systolic BP 170mmHg or more OR diastolic BP 110mmHg or more — medical emergency — urgent medical consult

Hypertension can cause

• Poor growth of baby
• Death of unborn baby 
• Placental abruption (part or all of placenta comes away from wall of uterus)
• Preterm labour or preterm birth
• Worsening of chronic high BP — 'end-organ' damage for mother, eg to kidneys, liver, brain
• Eclampsia (seizures when severe high BP)

Check

• Assess risk factors for preeclampsia at first antenatal visit — Table 2.14
  
• If risk factors — medical consult
• May need to see obstetrician early in pregnancy
• May suggest low dose aspirin or calcium supplements to reduce risk
• If risk factors — urinalysis for protein each visit

Do — if BP high at antenatal visit

• Take BP again after woman has rested for 10 minutes
• Finish routine antenatal check — note if protein on U/A
• Check file notes for
• Risk factors for preeclampsia
• Gestation (how many weeks pregnant)
• U/A or albumin creatinine ratio (ACR) results earlier in pregnancy — any protein
• Last urine MC&S
• Ask about symptoms of preeclampsia —  Table 2.15
• Check for signs of preeclampsia —  Table 2.15

• Medical consult about findings and management
• If managing as preeclampsia — see Preeclampsia straight away
• If managing as high BP — see Pregnancy-induced high BP or Chronic high BP

Pregnancy-induced hypertension

Need to send to hospital to check for preeclampsia and work out management plan

Check

• If signs or symptoms of preeclampsia — urine for U/A and MC&S

Do

• Bloods for FBC, UEC, LFT
• Medical consult about sending to hospital — straight away or non-urgent referral
• If sending to hospital straight away
• Medical consult about whether to start anti-hypertensive medicine to reduce BP
• Check BP every hour until transfer
• Urgent medical consult if systolic more than 160mmHg or diastolic 100mmHg
• If non-urgent referral
• See every day while waiting for hospital appointment
• Do routine antenatal check
• Ask about symptoms of preeclampsia — Table 2.15
• Medical consult every day about findings

If ongoing management in community

After review in hospital — may be managed in community. Management plan should include

• More frequent antenatal checks
• Ask about symptoms of preeclampsia at each visit — Table 2.15
• Medical consult about findings from each visit
• Regular hospital checks, including obstetric ultrasounds and cardiotocogram (CTG)
• Plan for birth in hospital — may need epidural or caesarean section

BP control

• BP target — usually less than 140/90mmHg
• Plan to send to hospital if preeclampsia or severe high BP develop
• Do not use ACE inhibitor or ARB to control BP — contraindicated in pregnancy
• Often use methyldopa or labetalol
• Always use if systolic BP 160mmHg or more or diastolic BP 100mmHg or more
• May be used if systolic BP 140–160mmHg or diastolic BP 90–100mmHg

 Investigations

• Take blood for FBC, UEC, LFT once a week, or twice a week if preeclampsia
• Take blood on day transport is available — so it gets to lab in time for platelet count
• If low platelet count or falling Hb — take blood for clotting studies, blood film, LDH, fibrinogen
• Collect urine for ACR (albumin creatinine ratio rather than 24 hour collection) once or twice a week

Follow-up

• See Postnatal follow-up of women with high BP in pregnancy

Chronic hypertension

If planning pregnancy — see Preconception care

Check

First antenatal visit

• Check file notes — history of kidney disease, BP management plan
• Also take blood for UEC, LFT, uric acid
• Urine albumin creatinine ratio (ACR)

After 20 weeks

• For signs or symptoms of preeclampsia — Table 2.15

Do

First antenatal visit

• Medical consult — medicines review
• Review beta blockers and diuretics
• Stop ACE inhibitor or ARB — both contraindicated in pregnancy
• Use a safer BP lowering medicine — methyldopa oral — 125mg twice a day (bd) increasing as required up to 500mg 3 times a day (tds)
  OR clonidine oral — 50microgram twice a day (bd) increasing as required up to 300microgram twice a day (bd)
  AND aspirin oral — 75–150mg at night 
  AND calcium supplement oral — 1.5g daily
• Arrange renal ultrasound (if not already done) to look for causes of high BP. Do at same time as obstetric ultrasound
• Arrange medical follow up, refer to specialist and obstetrician as required

Follow management plan

• Routine antenatal care
• Additional monitoring and treatment as advised by specialist
• BP target
• Plan for birth in hospital — may need epidural or caesarean section

Follow-up

• See Follow-up of medical problems in pregnancy — High BP

Unplanned birth in community

If woman with high BP goes into labour in community

Do not

Do not give nifedipine to stop labour unless instructed by obstetrician — may be asked to give nifedipine to control BP

Do not use ergometrine alone or in combination. Only use plain oxytocin

Do

• Urgent medical consult about 
• Sending to hospital
• Stopping labour with nifedipine
• Management plan if birthing in community
• If labour proceeds 
• See Labour and birth
• Give good pain relief as directed by doctor or midwife
• Get ready for a sick baby — see Newborn resuscitation
• Be ready in case woman has a fit
• Send mother and baby to hospital after birth — still at risk of complications