EM · Hypertensive disorders of pregnancy
Pre-eclampsia and eclampsia
Also known as Pre-eclampsia · Eclampsia · Severe pre-eclampsia · HELLP syndrome · Hypertensive disorder of pregnancy
Pre-eclampsia is new hypertension (at or above 140 over 90) after 20 weeks of gestation with proteinuria or end-organ dysfunction, progressing on a spectrum through severe pre-eclampsia to eclampsia (the seizure) and HELLP syndrome (haemolysis, elevated liver enzymes, low platelets). Management rests on three pillars: magnesium sulphate for seizure prophylaxis and treatment (4 g IV loading over 20 minutes then 1 to 2 g per hour, with calcium gluconate 10 mL of 10 per cent as the antidote for toxicity), blood-pressure control of the severe range (labetalol, hydralazine or nifedipine; acute trial target 140 to 150 over 90 to 100; no ACE inhibitors or ARBs), and delivery as the only cure. ACEM-primary, globally tagged.
Checked against its sources on 1 Sept 2026
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- Pre-eclampsia is new hypertension after 20 weeks with proteinuria or end-organ dysfunction — severe features (BP at or above 160 over 110, platelets below 100, transaminases twice normal, pulmonary oedema, cerebral or visual symptoms) trigger magnesium sulphate and delivery
- Magnesium sulphate is the cornerstone for seizure prophylaxis and treatment — 4 g IV loading over 20 minutes and 1 to 2 g per hour for 24 hours; calcium gluconate 10 mL of 10 per cent is the antidote for toxicity (loss of the patellar reflexes is the first warning)
- Control severe-range blood pressure toward 140 to 150 over 90 to 100 with labetalol, hydralazine or nifedipine — ACE inhibitors and ARBs are not for use in pregnancy
- Delivery is the only cure for pre-eclampsia — magnesium sulphate continues for 24 hours postpartum
- Pre-eclampsia and eclampsia may present de novo in the postpartum period from 48 hours to six weeks, most often within the first 7 to 10 days — a normal antenatal course does not exclude it
Meet the patient
A 19-year-old primigravida at 34 weeks lands in the triage bay at 3am with a two-day frontal headache that paracetamol will not shift, blurred vision and nausea. The triage nurse reads 168 over 106, the dipstick shows 3+ protein, and as you walk up she has brisk reflexes with clonus.[10]
The question that decides her next hour is the question that decides every pre-eclampsia: has she crossed into severe disease? If she has, the magnesium runs now, the pressure comes down to a controlled range, and the obstetric team is already on the phone about delivery.[10]
References20ShowHide
- [1]Magee LA, Brown MA, Hall DR, et al. The 2021 International Society for the Study of Hypertension in Pregnancy classification, diagnosis & management recommendations for international practice Pregnancy Hypertens, 2022.PMID 35066406
- [2]Altman D, Carroli G, Duley L, et al. Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial Lancet, 2002.PMID 12057549
- [3]Eclampsia Trial Collaborative Group Which anticonvulsant for women with eclampsia? Evidence from the Collaborative Eclampsia Trial Lancet, 1995.PMID 7769899
- [4]Duley L, Gülmezoglu AM, Henderson-Smart DJ, et al. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia Cochrane Database Syst Rev, 2010.PMID 21069663
- [5]von Dadelszen P, Payne B, Li J, et al. Prediction of adverse maternal outcomes in pre-eclampsia: development and validation of the fullPIERS model Lancet, 2011.PMID 21185591
- [6]Hauspurg A, Jeyabalan A Postpartum preeclampsia or eclampsia: defining its place and management among the hypertensive disorders of pregnancy Am J Obstet Gynecol, 2022.PMID 35177218
- [7]Rolnik DL, Wright D, Poon LC, et al. Aspirin versus Placebo in Pregnancies at High Risk for Preterm Preeclampsia N Engl J Med, 2017.PMID 28657417
- [8]Magee LA, von Dadelszen P, Rey E, et al. Less-tight versus tight control of hypertension in pregnancy N Engl J Med, 2015.PMID 25629739
- [9]Lu JF, Nightingale CH Magnesium sulfate in eclampsia and pre-eclampsia: pharmacokinetic principles Clin Pharmacokinet, 2000.PMID 10803454
- [10]Leeman L, Dresang LT, Fontaine P Hypertensive disorders of pregnancy Am Fam Physician, 2016.PMID 26926408
- [11]Haram K, Svendsen E, Abildgaard U The HELLP syndrome: clinical issues and management. A review BMC Pregnancy Childbirth, 2009.PMID 19245695
- [12]Vigil-De Gracia P, Lasso M, Ruiz E, et al. Severe hypertension in pregnancy: hydralazine or labetalol. A randomized clinical trial Eur J Obstet Gynecol Reprod Biol, 2006.PMID 16621226
- [13]Vermillion ST, Scardo JA, Newman RB, Chauhan SP A randomized, double-blind trial of oral nifedipine and intravenous labetalol in hypertensive emergencies of pregnancy Am J Obstet Gynecol, 1999.PMID 10521742
- [14]Ghesquiere L, Guerby P, Marchant I, et al. Comparing aspirin 75 to 81 mg vs 150 to 162 mg for prevention of preterm preeclampsia: systematic review and meta-analysis Am J Obstet Gynecol MFM, 2023.PMID 37146687
- [15]Abdul MA, Nasir UI, Khan N, Yusuf MD Low-dose magnesium sulphate in the control of eclamptic fits: a randomized controlled trial Arch Gynecol Obstet, 2013.PMID 22930148
- [16]Omu AE, Al-Harmi J, Vedi HL, et al. Magnesium sulphate therapy in women with pre-eclampsia and eclampsia in Kuwait Med Princ Pract, 2008.PMID 18408392
- [17]Adebayo JA, Nwafor JI, Lawani LO, et al. Efficacy of nifedipine versus hydralazine in the management of severe hypertension in pregnancy: a randomised controlled trial Niger Postgrad Med J, 2020.PMID 33154284
- [18]Rodrigues I, Quintela C, Jardim J, et al. Neonatal renal failure following intrauterine exposure to an angiotensin-converting enzyme inhibitor Cureus, 2024.PMID 38465020
- [19]Zeisler H, Llurba E, Chantraine F, et al. Predictive value of the sFlt-1:PlGF ratio in women with suspected preeclampsia N Engl J Med, 2016.PMID 26735990
- [20]National Institute for Health and Care Excellence Hypertension in pregnancy: diagnosis and management NICE guideline NG133, 2019.Source