This Article Full Text Full Text (PDF) Submit a related Letter to the Editor Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by van der Kamp, H. J. Articles by Verkerk, P. H. Search for Related Content PubMed PubMed Citation Articles by van der Kamp, H. J. Articles by Verkerk, P. H. Related Collections Adrenal and Hypertension Pediatric Endocrinology

Cutoff Levels of 17--Hydroxyprogesterone in Neonatal Screening for Congenital Adrenal Hyperplasia Should Be Based on Gestational Age Rather Than on Birth Weight

Department of Pediatrics (H.J.v.d.K., J.M.W.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands; Organization for Applied Scientific Research (TNO) Prevention and Health (C.G.M.O., P.H.V.), 2301 CE Leiden, The Netherlands; Diagnostic Laboratory for Infectious Diseases and Perinatal Screening (B.H.E.), National Institute of Public Health and the Environment (RIVM), 3720 BA Bilthoven, The Netherlands; General Clinical Laboratory (M.v.B.), IJsselland Hospital, 2900 AR Capelle a/d IJssel, The Netherlands; and Department of Pediatric Endocrinology (B.J.O.), University Medical Center St. Radboud, 6500 HB Nijmegen, The Netherlands

Address all correspondence and requests for reprints to: H. J. van der Kamp, Department of Pediatrics, H-3Q, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands. E-mail: H.J.van_der_Kamp{at}LUMC.nl.

Objective: In newborn screening programs for congenital adrenal hyperplasia, 17--hydroxyprogesterone (17OHP) cutoff levels are based on birth weight (BW) or on gestational age (GA). We investigated which approach would result in the greatest specificity and sensitivity.

Study design: For the determination of 17OHP, a neonatal 17OHP assay was used in filter paper blood of 9492 newborns. The relationships between 17OHP and BW and between 17OHP and GA were studied by regression analysis. Reference curves with a specificity of 99.95% were constructed with the method that summarizes the distribution by three smoothed curves representing the skewness (L curve), the median (M curve), and the coefficient of variation (S curve). Median cutoff levels for BW and for GA according to the 99.95% reference curves were calculated.

Results: Regression analysis showed that GA is a better predictor of 17OHP than BW (R² was 50.6 vs. 35.8%, respectively). At a specificity of 99.95%, the calculated median 17OHP cutoff level was lower for GA [12.6 µg/liter (38 nmol/liter)] than for BW [17.6 µg/liter (54 nmol/liter)], thus leading to a greater sensitivity.

Conclusion: This study demonstrates that GA is a better predictor of 17OHP in newborns and will result in greater specificity than BW despite the fact that the determination of GA might be less reliable than BW.

This article has been cited by other articles:

				J. E. Lee, Y. Moon, M. H. Lee, Y. H. Jun, K. I. Oh, and J. W. Choi Corrected 17-Alpha-Hydroxyprogesterone Values Adjusted by a Scoring System for Screening Congenital Adrenal Hyperplasia in Premature Infants Ann. Clin. Lab. Sci., January 1, 2008; 38(3): 235 - 240. [Abstract] [Full Text] [PDF]