Gestational context
20 to 40 weeks
Maternal
- BP
- severe range is 160/110 or above, treat within 30 to 60 minutes
- Symptoms
- headache, visual change, epigastric pain
- Labs
- platelets, creatinine, transaminases, urine protein
- Reflexes and clonus once on magnesium
- Reflexes and clonus once on magnesium
Fetal
- Growth
- serial scans, placental insufficiency is the same disease
- Doppler
- umbilical artery when growth is restricted
- Monitoring
- NST or CTG at review and in labour
- Timing
- delivery is the cure, planned by severity and gestation
Definitions (SOGC 2022, with ACOG terms named)
| Diagnosis | Definition |
|---|---|
| Hypertension | Systolic 140 or more, or diastolic 90 or more, on two readings at least 15 minutes apart. Severe: 160/110 or more, confirmed within 15 minutes. |
| Chronic hypertension | Present before pregnancy or before 20 weeks. |
| Gestational hypertension | New hypertension at or after 20 weeks without the features of preeclampsia. |
| Preeclampsia | Hypertension at or after 20 weeks with one or more of: proteinuria, an adverse condition or severe complication (maternal organ dysfunction) or uteroplacental dysfunction (growth restriction, abnormal Doppler). SOGC no longer requires proteinuria. |
| Preeclampsia with severe features (ACOG) | The ACOG term for severe hypertension or end-organ involvement; SOGC uses adverse conditions and severe complications. The same patients, different words. |
| Superimposed preeclampsia | Chronic hypertension that develops the features of preeclampsia. |
| Eclampsia | A generalised seizure in a patient with preeclampsia, without another cause. |
| HELLP | Haemolysis, elevated liver enzymes, low platelets: a severe complication, with or without hypertension. |
Assessment
- Symptoms: headache, visual disturbance, epigastric or right upper quadrant pain, nausea and vomiting, dyspnoea, reduced movements. Ask every time.
- Examination: blood pressure in the correct cuff, seated, after rest; reflexes and clonus; oedema (unreliable); fundal height.
- Bloods: CBC (platelets), creatinine, AST/ALT, LDH, urate (a marker, not a criterion), urine protein-to-creatinine ratio (0.03 g/mmol or more, or 300 mg/24 h).
- Fetal: growth, liquor, umbilical artery Doppler, monitoring.
- sFlt-1/PlGF ratio, where available, helps rule out preeclampsia in the short term when the picture is uncertain.
Management
- 1
Treat severe hypertension within 30 to 60 minutes
Oral nifedipine, intravenous labetalol or intravenous hydralazine; the choice depends on the setting and contraindications (asthma for labetalol). The target is 140 to 150 over 90 to 100, not normal: dropping the pressure too fast reduces placental perfusion.
- 2
Treat non-severe hypertension too
SOGC recommends treating to a diastolic of about 85 (the CHIPS trial): labetalol, nifedipine or methyldopa. ACE inhibitors and ARBs are contraindicated.
- 3
Magnesium sulfate
For eclampsia prophylaxis in preeclampsia with severe features or adverse conditions, and for treatment of eclampsia: loading dose then infusion, with monitoring of reflexes, respiratory rate and urine output. Calcium gluconate is the antidote.
- 4
Decide on delivery
Delivery is the cure. Preeclampsia at 37 weeks or more is delivered. Before 34 weeks, expectant management with steroids is reasonable if the mother and fetus are stable and the unit can watch closely; severe complications end it. Eclampsia, HELLP, uncontrollable hypertension, abruption and non-reassuring fetal status are delivered after stabilisation, at any gestation.
- 5
Postpartum
Blood pressure can peak on days 3 to 6. Preeclampsia and eclampsia occur postpartum. Continue treatment, review within a week, and counsel about long-term cardiovascular risk.
Eclampsia
Airway, left lateral, call for help, magnesium sulfate 4 g intravenously over 5 minutes then 1 g per hour; a further 2 g for a recurrent seizure. Control the blood pressure, then deliver once stable. The fetus recovers as the mother does; delivery during the seizure helps nobody.
Prevention
- Low-dose aspirin (81 to 162 mg at night) from 12 to 16 weeks until 36 weeks for those at high risk: prior preeclampsia, chronic hypertension, pre-existing diabetes, renal disease, autoimmune disease, multiple pregnancy, or several moderate risk factors.
- Calcium supplementation where dietary intake is low.
- Exercise; no evidence for salt restriction or bed rest.
Check
34 weeks, BP 168/112 repeated at 15 minutes, headache, platelets 95, AST 180. Which single step comes first?
On the modelPlacentaFundus and cornua