Table 11.12Calcium/creatinine ratio

Author, year, country, EL, study designNo. of women analysed, inclusion/exclusion criteria, age, gestational age at testReference standard used, incidence of PEIndex test cut-offResultsComments and conclusion
Rogers (1994)865 Hong Kong, EL II, cohort study199,
IN: normotensive primigravidas, singleton pregnancies
EX: congenital malformations
27.1 ± 3.8 years,
18–26 weeks
BP ≥ 140/90 mmHg ≥ twice
Prot. ≥ 0.3 g/litre,
4.0%
Cresolphtalein method (American Monitor)/Beckman Astra-8 analyser
0.3
ST 49%, SP 90%
Conde (1994)866 Argentina, EL II, prospective cohort study387 women,
IN: normotensive nulliparas, singleton pregnancies
EX: diabetes mellitus, renal disease, proteinuria, chronic hypertension, other chronic medical illnesses
23.8 ± 5.7 years,
20 weeks
SBP ≥ 140 or DBP ≥ 90 mmHg twice ≥ 6 hours apart
Prot. ≥ 0.3 g/litre,
3.4%
Colorimetric (direct)/picrato alcalino method
0.07
ST 33%, SP 78%, PPV 5%, NPV 97%Poor predictive values suggest that changes in the biochemical and haematologic tests occur only when pre-eclampsia has been established.
Kazerooni (2003)867 Iran, EL II, Prospective cross-sectional study102,
IN: nulliparas (18–35 years)
EX: renal disease, diabetes mellitus, proteinuria, chronic hypertension, other chronic medical illnesses
22.8 ± 4.5 years,
20–24 weeks
BP ≥ 140/90 mmHg or rise SBP ≥ 30 mmHg or DBP ≥ 15 mmHg twice ≥ 6 hours apart
Prot. ≥ 0.3 g/24 hours or ≥ 1+ dipstick,
7.8%
n.r.
≤ 0.001 mmol/litre (0.229 mg/100 ml: mg/100 ml)
ST 75%, SP
77.7%, PPV
20.7%, NPV
97%
Single urine calcium to creatinine ratio may be an effective method for screening women at the greatest risk of pre-eclampsia.
Baker (1994)864 UK, EL II, A prospective, non- interventional study500,
IN: Normotensive nulliparas
EX: renal disease, chronic hypertension
Median 27 years (range 24–31),
18–19 weeks
DBP ≥ 90 mmHg twice ≥ 4 hours apart
Prot. ≥ 0.3 g/24 hours,
2.6%
Perspective analyser (colorimetric)/Monarch centrifugal analyser (kinetic)
n.r.
ST 31%, SP 55%

(correctly predicted 71%)

From: 11, Screening for clinical problems

Cover of Antenatal Care
Antenatal Care: Routine Care for the Healthy Pregnant Woman.
NICE Clinical Guidelines, No. 62.
National Collaborating Centre for Women's and Children's Health (UK).
London: RCOG Press; 2008 Mar.
Copyright © 2008, National Collaborating Centre for Women’s and Children’s Health.

No part of this publication may be reproduced, stored or transmitted in any form or by any means, without the prior written permission of the publisher or, in the case of reprographic reproduction, in accordance with the terms of licences issued by the Copyright Licensing Agency in the UK [www.cla.co.uk]. Enquiries concerning reproduction outside the terms stated here should be sent to the publisher at the UK address printed on this page.

The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant laws and regulations and therefore for general use.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.