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ISSUE 4 AUGUST
Letters to the Editor

Pre-eclampsia

  • Colin Weatheril, Huy A Tran

The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

 

Letter to the Editor

Editor, – I read with interest the article on biochemical tests in pregnancy (Aust Prescr 2006;29:48-52) and wish to comment on the discussion of pre-eclampsia. The author maintains that the diagnosis is based on a triad of hypertension, proteinuria and oedema, yet the Australasian Society for the Study of Hypertension in Pregnancy has issued a consensus statement which asserts otherwise.1 While hypertension is a requirement, proteinuria (as one of a range of possible end organ effects) is not mandatory to make the diagnosis. Oedema is specifically excluded unless its onset is rapid and generalised. This is important to appreciate as severe forms of pre-eclampsia (and indeed eclampsia) can occur in the absence of the 'triad'. Furthermore, 'routine' urinalysis at each visit in low-risk pregnancies has been discontinued in many centres due to its limited value.

Colin Weatherill
Obstetrician
Mount Gambier, SA

 

Author's comments

Associate Professor HA Tran, author of the article, comments:

In pre-eclampsia the detection of hypertension is of utmost importance and blood pressure needs to be rigorously controlled. The presence of proteinuria and oedema is less critical but will further assist in arriving at the correct diagnosis. Although eclampsia can occur in the absence of the 'triad', alternative differential neurological diagnoses need to be considered.

While the clinical utility of 'routine' urinalysis may not be as important in the diagnosis of pre-eclampsia, it is sometimes useful in detecting asymptomatic bacteriuria and glycosuria. Bacteriuria confers an increased risk of pyelonephritis and prematurity,2 and glycosuria may identify unsuspected diabetes other than gestational diabetes. Interventions for both of these conditions can result in better outcomes.2,3 It is of additional interest that the current British guideline for antenatal care recommends that 'whenever blood pressure is measured in pregnancy a urine sample should be tested at the same time for proteinuria'.4 The decision to discontinue this practice in low-risk patients is then probably a function of cost versus benefit.

 

References

  1. Brown MA, Hague WM, Higgins J, Lowe S, Mc Cowan L, Oats J, et al. Australasian Society for the Study of Hypertension in Pregnancy. The detection, investigation and management of hypertension in pregnancy: full consensus statement. Aust N Z J Obstet Gynaecol 2000;40:139-55.
  2. Raz R. Asymptomatic bacteriuria - clinical significance and management. Nephrol Dial Transplant 2001;16 (Suppl 6):135-6.
  3. Crowther CA, Hiller JE, Moss JR, Mc Phee AJ, Jeffries WS, Robinson JS. Effect of treatment of gestational diabetes mellitus on pregnancy outcomes. N Engl J Med 2005;352:2477-86.
  4. Antenatal care: Routine care for the healthy pregnant woman. London: National Collaborating Centre for Women's and Children's Health; 2003. http://www.rcog.org.uk/resources/Public/pdf/Antenatal_Care.pdf [cited 2006 Jul 4]

Colin Weatheril

Obstetrician, Mount Gambier, SA

Huy A Tran

Head and Associate Professor, Department of Clinical Chemistry, Hunter Area Pathology Service, John Hunter Hospital, Newcastle University, Newcastle, New South Wales