Tiny Tip: PREeclampsia

In Tiny Tips by Sarah Luckett-Gatopoulos3 Comments

Preeclampsia is a common complication in pregnancy, affecting 3-5% of pregnant women in the general population, and up to 25% of pregnant patients with pre-existing chronic hypertension [1].

It’s common enough that you’re likely to see it in the emergency department if you are rotating through a site without a primary obstetrics triage area. It’s important to recognise preeclampsia early in the emergency department, because unrecognised it can lead to eclampsia and increase the risk of early induced labour, placental abruption, and foetal growth restriction [2].


The classic preeclampsia triad can be remembered using the mnemonic PRE:

P roteinuria

R ising blood pressure

E dema


If you’ve done a urine dipstick in the emergency department, you can reasonably suspect significant proteinuria with a result of 1+. Formal diagnostic criteria require a 24-hour urine collection showing 0.3g/day or 30mg/mmol in a random urine sample [3].

If you suspect hypertension in the emergency department (systolic blood pressure 140 mmHg or diastolic pressure 90 mmHg), be sure to confirm by taking at least 2 measurements in the same arm, waiting at least 15 minutes between measurements [3].

As for edema, swelling of the legs and feet is pretty common in pregnancy, but residents and staff in obstetrics and gynaecology tell me that facial swelling is the hallmark of preeclampsia edema…and it can happen overnight, so it’s usually noticed and reported by patients and partners!

Reviewing with the Staff (by T. Chan)

Staff Review by Teresa Chan MD FRCPC

Thanks for the great piece, Luckett. One thing I wanted to call out was to ensure that readers remember one key clinical pearl: It’s good to remember what preeclampsia looks like so that you can treat it! Therefore, I have two bonus tips that I would like to highlight:



Remember, (full) eclampsia should be treated with magnesium sulphate (2014 SOGC recommendation 116) [3]. Magnesium sulphate should also be given to preeclamptic patients with severe preeclampsia (2014 SOGC recommendation 117) and may be considered as prophylaxis in women with non-severe eclampsia and at least one of the following symptoms [3]:

  • severe hypertension,
  • headaches/visual symptoms,
  • right upper quadrant/epigastric pain,
  • platelet count < 100 000 × 109/L,
  • progressive renal insufficiency,
  • elevated liver enzymes (I-C)

Please note that this list is VERY SIMILAR to the HELLP syndrome, but slightly different – and thus learners should be flagged to the obvious confusion that this might cause. (Good thing you have previously also reviewed HELLP for Tiny Tips recently! :D)



The dose of Magnesium sulphate for prophylaxis of eclampsia is 4 g IV load (over 20 min) and then 1 g / hr [4].


1. Seely, E. W., & Ecker, J. (2011). Chronic hypertension in pregnancy. New England Journal of Medicine, 365(5), 439-446. PMID: 24637432

2. Arulkumaran, N., & Lightstone, L. (2013). Severe pre-eclampsia and hypertensive crises. Best Practice & Research Clinical Obstetrics & Gynaecology, 27(6), 877-884. PMID: 23962474 

3. Magee, L. A., Pels, A., Helewa, M., Rey, E., von Dadelszen, P., Audibert, F., … & Sebbag, I. (2014). Diagnosis, Evaluation, and Management of the Hypertensive Disorders of Pregnancy: Executive Summary. Journal of obstetrics and gynaecology Canada: JOGC= Journal d’obstetrique et gynecologie du Canada: JOGC, 36(5), 416-438.  PMID: 23962474

4.  Altman, D., Carroli, G., Duley, L., Farrell, B., Moodley, J., Neilson, J., & Smith, D. (2002). Do women with pre-eclampsia, and their babies, benefit from magnesium sulphate? The Magpie Trial: a randomised placebo-controlled trial. Lancet359(9321), 1877-1890.  PMID: 12057549

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Sarah Luckett-Gatopoulos

Sarah Luckett-Gatopoulos

Senior Editor at BoringEM
Luckett is a resident at McMaster University. Interested in literacy, health advocacy, creative writing, and near-peer mentorship.
Sarah Luckett-Gatopoulos
- 2 weeks ago
BoringEM has been 'bringing the boring' to emergency medicine since 2012. In 2016 this Canadian blog brought its content to CanadiEM.
- 2 years ago