HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: clinchem.2005.064899v1 52/6/1138    most recent Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Mosca, A. Articles by Lapolla, A. Search for Related Content PubMed PubMed Citation Articles by Mosca, A. Articles by Lapolla, A. Related Collections Endocrinology and Metabolism

Reference Intervals for Hemoglobin A_1c in Pregnant Women: Data from an Italian Multicenter Study

¹ Dipartimento di Scienze e Tecnologie Biomediche, Università degli Studi di Milano, Segrate (Milano), Italy.
² Dipartimento di Scienze Mediche e Chirurgiche, Università di Padova, Padova, Italy.
³ Dipartimento di Endocrinologia e Metabolismo and⁴ Laboratorio Analisi, Azienda Ospedaliera-Universitaria Pisa, Pisa, Italy.
⁵ Centro Antidiabetico and⁶ Laboratorio di Biochimica, H. Maggiore Ca’ Granda, Milano, Italy.
⁷ Diagnostica e Ricerca S. Raffaele spa and⁸ Divisione di Ostetricia e Ginecologia, IRCCS H. San Raffaele, Milano, Italy.
⁹ Centro Antidiabetico, Ospedale Brotzu, Cagliari, Italy.
¹⁰ Servizio Medicina di Laboratorio, Azienda Ospedaliera-Università di Padova, Padova, Italy.

^aAddress correspondence to this author at: Dipartimento di Scienze e Tecnologie Biomediche, Università degli Studi di Milano, Via Fratelli Cervi 93, 20090 Segrate, Milano, Italy. Fax 39-02-5033-0414; e-mail andrea.mosca{at}unimi.it.

Background: The reference intervals for hemoglobin A_1c (Hb A_1c) in pregnant women without diabetes are not well defined, and few examples of reference intervals established by networks of different laboratories are available.

Methods: Five Italian Diabetic Care Units were involved in the study. Data were collected from 445 pregnant women without diabetes, selected on the basis of glucose challenge test results, and from 384 nonpregnant control women. The Hb A_1c measurements were performed with HPLC systems aligned to the Diabetes Control and Complications Trial. Plasma glucose measurements were also performed locally. Both Hb A_1c and glucose measurements were harmonized by running appropriate external quality assessment schemes. The reference intervals were calculated in terms of nonparametric 2.5th to 97.5th percentiles with 0.90 confidence intervals.

Results: The Hb A_1c measurements were reproducible (CV = 2.0%) and accurate [mean (SE) difference from the target values, –0.10 (0.06)%]. Glucose measurements were also reproducible (mean CV = 3.2%) and accurate [difference from the target values, –0.01 (0.04) mmol/L]. To calculate common reference intervals, we merged the data collected in the different centers. The Hb A_1c reference intervals were 4.0%–5.5% for pregnant nondiabetic women and 4.8%–6.2% for nonpregnant controls.

Conclusions: Healthy pregnant women have lower Hb A_1c concentrations than nonpregnant women. The reference intervals for Hb A_1c in pregnant women should therefore be lower than those currently in use.

The following articles in journals at HighWire Press have cited this article:

				J. L. Kitzmiller, J. M. Block, F. M. Brown, P. M. Catalano, D. L. Conway, D. R. Coustan, E. P. Gunderson, W. H. Herman, L. D. Hoffman, M. Inturrisi, et al. Managing Preexisting Diabetes for Pregnancy: Summary of evidence and consensus recommendations for care Diabetes Care, May 1, 2008; 31(5): 1060 - 1079. [Full Text] [PDF]

				L. Herranz, L. Saez-de-Ibarra, C. Grande, and L. F. Pallardo Non-Glycemic-Dependent Reduction of Late Pregnancy A1C Levels in Women With Type 1 Diabetes Diabetes Care, June 1, 2007; 30(6): 1579 - 1580. [Full Text] [PDF]