Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Sep 3;7(9):e2435136.
doi: 10.1001/jamanetworkopen.2024.35136.

Preconception HbA1c Levels in Adolescents and Young Adults and Adverse Birth Outcomes

Katharine J McCarthy  1   2 , Shelley H Liu  1 , Joseph Kennedy  3 , Hiu Tai Chan  3 , Frances Howell  4 , Natalie Boychuk  4 , Victoria L Mayer  1   5 , Luciana Vieira  6 , Bahman Tabaei  7 , Kacie Seil  3 , Gretchen Van Wye  3 , Teresa Janevic  4
Affiliations

Preconception HbA1c Levels in Adolescents and Young Adults and Adverse Birth Outcomes

Katharine J McCarthy et al. JAMA Netw Open. .

Abstract

Importance: Subclinical hyperglycemia before pregnancy may be associated with the likelihood of maternal morbidity but is understudied among young people.

Objective: To explore the association of preconception hemoglobin A1c (HbA1c) levels among adolescents and young adults with risk of gestational diabetes at first live birth.

Design, setting, and participants: This retrospective cohort study used linked 2009 to 2017 birth registry, hospital discharge, and New York City Department of Health A1C Registry data for birthing individuals aged 10 to 24 years with no history of diabetes and at least 1 preconception HbA1c test in New York, New York. Statistical analysis was performed from August to November 2022.

Exposure: Preconception HbA1c values categorized as no diabetes (HbA1c <5.7%) or prediabetes (HbA1c ≥5.7% to <6.5%).

Main outcomes and measures: The primary outcome was gestational diabetes at first birth. Secondary outcomes included hypertensive disorders of pregnancy, preterm birth, cesarean delivery, and macrosomia. Log binomial regression was used to estimate the relative risk (RR) of gestational diabetes at first birth by preconception HbA1c level, adjusting for prepregnancy characteristics. The optimal HbA1c threshold for gestational diabetes was examined using receiver operating curve regression.

Results: A total of 14 302 individuals (mean [SD] age, 22.10 [1.55] years) met study eligibility criteria. Of these, 5896 (41.0%) were Hispanic, 4149 (29.0%) were Black, 2583 (18.1%) were White, 1516 (10.6%) were Asian, and 185 (1.3%) had other or unknown race and ethnicity. Most (11 407 individuals [79.7%]) had normoglycemia before pregnancy, and 2895 individuals (20.2%) had prediabetes. Adjusting for prepregnancy characteristics, those with preconception prediabetes had more than twice the risk of gestational diabetes vs those with normoglycemia (adjusted RR [aRR], 2.21; 95% CI, 1.91-2.56). Preconception prediabetes was associated with small increases in the likelihood of a hypertensive disorder of pregnancy (aRR, 1.18; 95% CI, 1.03-1.35) and preterm delivery (aRR, 1.18; 95% CI, 1.02-1.37). The aRRs for cesarean delivery (aRR, 1.09; 95% CI, 0.99-1.20) and macrosomia (aRR, 1.13; 95% CI, 0.93-1.37) were increased but not statistically significant. The optimal HbA1c threshold to identify gestational diabetes among adolescents and young adults was 5.6%. The threshold did not vary by obesity status but was slightly lower among Hispanic individuals (HbA1c of 5.5%).

Conclusions and relevance: In this study of adolescents and young adults with at least 1 preconception HbA1c test, prediabetes was associated with increased likelihood of maternal cardiometabolic morbidity at first birth. Efforts to optimize cardiometabolic health before pregnancy may avert excess maternal risk.

PubMed Disclaimer

Conflict of interest statement

Conflict of Interest Disclosures: Dr Liu reported receiving grants from National Institute of Child Health and Human Development 5K25HD104918 during the conduct of the study. No other disclosures were reported.

References

    1. American Diabetes Association . 2. Classification and diagnosis of diabetes: Standards of Medical Care in Diabetes-2020. Diabetes Care. 2020;43(suppl 1):S14-S31. doi:10.2337/dc20-S002 - DOI - PubMed
    1. Magge SN, Silverstein J, Elder D, Nadeau K, Hannon TS. Evaluation and treatment of prediabetes in youth. J Pediatr. 2020;219:11-22. doi:10.1016/j.jpeds.2019.12.061 - DOI - PMC - PubMed
    1. Liu J, Li Y, Zhang D, Yi SS, Liu J. Trends in prediabetes among youths in the US from 1999 through 2018. JAMA Pediatr. 2022;176(6):608-611. doi:10.1001/jamapediatrics.2022.0077 - DOI - PMC - PubMed
    1. Menke A, Casagrande S, Cowie CC. Prevalence of diabetes in adolescents aged 12 to 19 years in the United States, 2005-2014. JAMA. 2016;316(3):344-345. doi:10.1001/jama.2016.8544 - DOI - PubMed
    1. Andes LJ, Cheng YJ, Rolka DB, Gregg EW, Imperatore G. Prevalence of prediabetes among adolescents and young adults in the United States, 2005-2016. JAMA Pediatr. 2020;174(2):e194498. doi:10.1001/jamapediatrics.2019.4498 - DOI - PMC - PubMed

Publication types

Substances