OBJECTIVE: To estimate the relationship between 1-hour 50 g glucose challenge test values and perinatal outcomes.
METHODS: This was a secondary analysis of data from a multicenter treatment trial of mild gestational diabetes mellitus. Women with glucose challenge test values of 135–199 mg/dL completed a 3-hour oral glucose tolerance test. Mild gestational diabetes mellitus was defined as fasting glucose less than 95 mg/dL and two or more abnormal oral glucose tolerance test values: 1-hour 180 mg/dL or more; 2-hour 155 mg/dL or more; and 3-hour 140 mg/dL or more. Our study included untreated women with glucose challenge test values of 135–139 mg/dL and 140–199 mg/dL and a comparison group with values less than 120 mg/dL. Primary outcomes included a perinatal composite (stillbirth, neonatal death, hypoglycemia, hyperbilirubinemia, neonatal hyperinsulinemia, and birth trauma), large for gestational age (LGA, birth weight above the 90th percentile based on sex-specific and race-specific norms), and macrosomia (greater than 4,000 g).
RESULTS: There were 436 women with glucose challenge test values less than 120 mg/dL and 1,403 with values of 135 mg/dL or more (135–139, n=135; 140–199, n=1,268). The composite perinatal outcome occurred in 25.6% of those with glucose challenge test values less than 120 mg/dL compared with 21.1% for values of 135–139 mg/dL and 35.3% for values of 140–199 mg/dL. Rates of LGA by group were 6.6%, 6.8%, and 12.4%, respectively. Rates of macrosomia by group were 7.8%, 6.1%, and 12.1%, respectively. Compared with glucose challenge test values less than 120 mg/dL, the adjusted odds ratios (ORs) (95% confidence intervals [CIs]) for values of 140–199 mg/dL were 1.48 (1.14–1.93) for the composite outcome, 1.97 (1.29–3.11) for LGA, and 1.61 (1.07–2.49) for macrosomia. For glucose challenge test values of 135–139 mg/dL, adjusted ORs and 95% CIs were 0.75 (0.45–1.21), 1.04 (0.44–2.24), and 0.75 (0.30–1.66), respectively. The subcategories with glucose challenge test values of 140–144 mg/dL and 145–149 mg/dL also were associated with an increase in selected outcomes when compared with those with values less than 120 mg/dL.
CONCLUSIONS: Glucose challenge test values of 135–139 mg/dL were not associated with adverse outcomes compared with values less than 120 mg/dL; however, glucose challenge test values of 140 mg/dL or more were associated with an increase in odds of the composite perinatal outcome, LGA, and macrosomia.
LEVEL OF EVIDENCE: II
One-hour 50-g glucose challenge test values of 140 mg/dL or more, but not 135–139 mg/dL, are associated with an increase in a composite of adverse perinatal outcomes and large-for-gestational-age and macrosomic neonates.
Departments of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama, The Ohio State University, Columbus, Ohio, University of Texas Health Science Center at Houston, Houston, Texas, University of Texas Southwestern Medical Center, Dallas, Texas, Columbia University, New York, New York, University of Utah, Salt Lake City, Utah, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, Drexel University, Philadelphia, Pennsylvania, Case Western Reserve University-MetroHealth Medical Center, Cleveland, Ohio, Wake Forest University Health Sciences, Winston-Salem, North Carolina, University of Texas Medical Branch, Galveston, Texas, University of Pittsburgh, Pittsburgh, Pennsylvania, Wayne State University, Detroit, Michigan, Northwestern University, Chicago, Illinois, and Oregon Health & Science University, Portland, Oregon; The George Washington University Biostatistics Center, Washington, DC; and the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland.
Corresponding author: Dana Figueroa, MD, 176F 10270C, 619 19th Street S, Birmingham, AL 35249-7333; e-mail: firstname.lastname@example.org.
Supported by grants from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) (HD27915, HD34116, HD40485, HD34208, HD27869, HD40500, HD40560, HD34136, HD40544, HD27860, HD40545, HD53097, HD21410, HD27917, HD40512, HD53118, HD36801), a General Clinical Research Centers Grant (M01-RR00034), and the National Center for Research Resources (UL1-RR024989, M01-RR00080, UL1-RR025764, C06-RR11234) and does not necessarily represent the official views of the NICHD or the National Institutes of Health.
Financial Disclosure The authors did not report any potential conflicts of interest.
Presented in part as a poster at the 31st Annual Meeting of the Society for Maternal-Fetal Medicine, February 9–12, 2011, San Francisco, California.
* For a list of other members of the NICHD MFMU, see the Appendix online at http://links.lww.com/AOG/A386.
The authors thank Alan T. N. Tita, MD, PhD, for assistance with study design and manuscript development; Francee Johnson, RN, Joanne Tillinghast, RN, and Susan Tolivasia for coordination between clinical research centers; and Elizabeth Thom, PhD, for study design, data management, statistical analysis, and manuscript development.
Dr. Spong and Dr. Rouse, Associate Editors of Obstetrics & Gynecology, were not involved in the review or decision to publish this article.