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Preeclampsia and hypertension in pregnancy
Preeclampsia is a placental disease that shows itself as hypertension after week 20 with end-organ injury; the only cure is delivery, and everything else is about buying time safely.
Why it matters in the exam
Exam questions separate four conditions: chronic hypertension (before week 20), gestational hypertension, preeclampsia with or without severe features, and HELLP syndrome. The decision a question usually turns on is when to deliver: at 37 weeks without severe features, and at 34 weeks or immediately when severe features are present. Candidates are also asked for the magnesium sulfate dose, the signs of magnesium toxicity and its antidote, and which drugs bring severe hypertension down within an hour.
Another group of questions is about prevention: women at high risk receive low-dose aspirin, started between 12 and 16 weeks and continued until 36 weeks. Know the risk factors: preeclampsia in a previous pregnancy, multiple pregnancy, chronic hypertension, diabetes, kidney disease and autoimmune disease such as lupus or antiphospholipid syndrome. Remember that preeclampsia can also appear after delivery, up to 6 weeks postpartum, so a new headache in the first postnatal week calls for a blood pressure measurement.
Key points
- Gestational hypertension and preeclampsia start after week 20; before that it is chronic hypertension.
- Severe features: BP 160/110 or more, low platelets, liver, kidney, lungs and brain.
- Deliver at 37 weeks without severe features, and at 34 weeks or immediately with them.
- Magnesium sulfate prevents seizures; its toxicity is treated with calcium gluconate.
- Low-dose aspirin from 12–16 weeks until 36 weeks for women at high risk.
Summary table
| Condition | Definition | Deciding findings | What to do |
|---|---|---|---|
| Chronic hypertension | BP 140/90 or more before week 20 or before pregnancy | No proteinuria early in pregnancy | Continue labetalol or nifedipine; watch for superimposed preeclampsia |
| Gestational hypertension | BP 140/90 or more after week 20, on two readings 4 hours apart | No proteinuria and no end-organ injury | Close surveillance; deliver at 37 weeks |
| Preeclampsia without severe features | Hypertension after week 20 with proteinuria: 300 mg per 24 hours or a protein-to-creatinine ratio of 0.3 or more | Normal laboratory tests and BP below 160/110 | Maternal and fetal surveillance; deliver at 37 weeks |
| Preeclampsia with severe features | BP 160/110 or more, or end-organ injury even without proteinuria | Platelets below 100,000, creatinine above 1.1, liver enzymes 2 times normal, pulmonary oedema, headache or visual disturbance | Magnesium sulfate, BP lowering, steroids before 34 weeks; deliver at 34 weeks |
| HELLP | Haemolysis, elevated liver enzymes, low platelets | LDH 600 or more, AST or ALT 2 times normal, platelets below 100,000 | Stabilise and deliver, whatever the gestational age |
| Eclampsia | New tonic-clonic seizure in a woman with preeclampsia | May occur without very high BP and after delivery | Magnesium sulfate, airway protection, delivery after stabilisation |
A free exam question
ריבוי מי שפיר עיקבי בטרימסטר שלישי קשור בעלייה בסיכון של מ ה ?מהבאים (the question as examined, in Hebrew)
- א. רעלת הריון
- ב. IUGR
- ג. כולסטאזיס הריוני
- ד. Amniotic Band Syndrome
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Sources
- ACOG Practice Bulletin No. 222, 2020 — Gestational Hypertension and Preeclampsia
- ISSHP classification, diagnosis and management recommendations, 2021 — The hypertensive disorders of pregnancy
- NICE guideline NG133, 2019, updated 2023 — Hypertension in pregnancy: diagnosis and management
- Williams Obstetrics, 26th edition (2022) — Hypertensive Disorders
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-02. The text may contain errors; when in doubt, check the source.