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Accuracy of 12‐hour urine collection in the diagnosis of pre‐eclampsia
Author(s) -
Silva Rita M.,
Pereira Sara R.,
Rego Susana,
Clode Nuno
Publication year - 2018
Publication title -
international journal of gynecology and obstetrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.895
H-Index - 97
eISSN - 1879-3479
pISSN - 0020-7292
DOI - 10.1002/ijgo.12536
Subject(s) - medicine , eclampsia , confidence interval , urine , prospective cohort study , preeclampsia , obstetrics , pregnancy , genetics , biology
Objective To evaluate the accuracy of a 12‐hour urine collection to diagnose pre‐eclampsia and to determine whether time of collection influences the performance of this test. Methods A prospective observational study was conducted in a tertiary obstetric center in Portugal between November 1, 2015, and November 30, 2016. Pregnant women (≥20 weeks) admitted for observation with suspected pre‐eclampsia were eligible for inclusion. Two consecutive 12‐hour urine samples were collected (07:00–19:00 hours vs 19:00–07:00 hours). Protein levels were measured in each 12‐hour sample, as well as in a pooled sample (07:00–07:00 hours). The diagnostic cut‐off values for pre‐eclampsia were 150 mg (12‐hour samples) and 300 mg (24‐hour sample). Results The study included 99 patients and diagnoses of pre‐eclampsia were confirmed among 42 (42%) patients. In all, 456 12‐hour urine samples were analyzed (equivalent to 228 24‐hour samples). Qualitative analysis (pre‐eclampsia vs no pre‐eclampsia) indicated substantial agreement between the 12‐ and 24‐hour samples (Cohen κ 0.779). The sensitivity was 85.9% (95% confidence interval [ CI ] 81%–90%) and the specificity was 91.7% (95% CI 88%–95%). No statistically significant difference was found between the two 12‐hour collections. Conclusion The 12‐hour test showed acceptable accuracy for detecting pre‐eclampsia, regardless of the time of collection.