help button home button Endocrine Society JCEM JCEM Call for Nominations for EIC
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Singh, P. K.
Right arrow Articles by Gronowski, A. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Singh, P. K.
Right arrow Articles by Gronowski, A. M.
The Journal of Clinical Endocrinology & Metabolism Vol. 88, No. 9 4175-4179
Copyright © 2003 by The Endocrine Society

COMMENT

Establishment of Reference Intervals for Markers of Fetal Thyroid Status in Amniotic Fluid

Pratima K. Singh, Curtis A. Parvin and Ann M. Gronowski

Washington University School of Medicine, Department of Pathology and Immunology, Division of Laboratory Medicine, St. Louis, Missouri 63110

Address all correspondence and requests for reprints to: Ann Gronowski, Ph.D., Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid, Box 8118, St. Louis, Missouri 63110. E-mail: gronowski{at}pathology.wustl.edu.

Fetal goiter can arise as a result of fetal hyper or hypothyroidism. Although this condition is rare, it can be life threatening. Detection of fetal goiter in utero is possible with the aid of ultrasound, but proper prenatal treatment depends on knowledge of hormonal status. Amniotic fluid (AF) sampling is less technically demanding and poses fewer risks to the fetus than cordocentesis for fetal serum sampling, but well-established reference ranges for AF thyroid studies are not available in the literature. We have established reference intervals for AF (TSH), total T4 (tT4), and free T4 using stored AF samples. The reference intervals were: TSH (n = 127), less than 0.1–0.5 mU/liter, with a median of 0.1 mU/liter; tT4 (n = 129), 2.3–3.9 µg/dl (30–50 nmol/liter), with a median of 3.3 µg/dl (4 nmol/liter); and free T4 (n = 119) less than 0.4–0.7 ng/dl (5–9 pmol/liter), with a median of 0.4 ng/dl (5 pmol/liter). These intervals represent the largest study done to date on third trimester AF using automated immunoassays. A literature search of fetal goiter revealed a number of cases of hypothyroidism. Seven cases reported AF TSH concentrations (range, 1.1–28.9 mU/liter) and four reported AF tT4 concentrations [range, 0.98–1.25 µg/ml (13–16 nmol/liter)], all of which fell outside our reference intervals. These data support the use of AF to diagnose fetal hypothyroidism, reducing the need to resort to a riskier procedure such as cordocentesis.

This study has been presented in part at the Academy of Clinical Laboratory Physicians and Scientists Annual Meeting, New York, NY, June 2002. This research was sponsored in part by Abbott Laboratories by supplying reagents.

Abbreviations: AF, Amniotic fluid; fT4, free T4; SI, Système Internationale; tT4, total T4.






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 2003 by The Endocrine Society