title: Antenatal haemoglobin A1c and risk of large-for-gestational-age infants in a multi-ethnic cohort of women with gestational diabetes.
abstract: Gestational diabetes mellitus (GDM) is a risk factor for delivering a large-for-gestational-age (LGA) infant. Haemoglobin A1c (A1C) is an indicator of glycaemic control. The objective of this study was to test whether higher A1C quartile at the time of diagnosis of GDM is associated with increased risk of delivering a LGA or macrosomic infant. Women with singleton pregnancies treated for GDM at a large diabetes and pregnancy programme located in Charlotte, North Carolina, were eligible for inclusion in this retrospective cohort study. Clinical information, including A1C at diagnosis, treatment, prior medical and obstetric history, and birth data were abstracted from medical records. LGA was defined as birthweight >90th percentile for gestational age and sex and macrosomia as birthweight >4000 g. Logistic regression was used to analyse the association of A1C at GDM diagnosis with risk of delivering LGA or macrosomic infants. This study included 502 women. Prevalences of LGA and macrosomia were 4% and 6% respectively. After adjustment there was no detectable trend of increased risk for LGA (P for trend = 0.12) or macrosomia (P for trend = 0.20) across increasing quartiles of A1C at GDM diagnosis. A1C at GDM diagnosis may not be linearly associated with LGA or macrosomia, possibly because of the mediating effect of strict glycaemic control in this clinical setting.
authors.affiliation: Departments of Epidemiology Health Services Biostatistics, University of Washington VA Puget Sound Health Care System, Seattle, WA 98195, USA. jkaton@u.washington.edu
authors.forename: Jodie
authors.initials: J
authors.lastname: Katon
authors.forename: Gayle
authors.initials: G
authors.lastname: Reiber
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Williams
authors.forename: David
authors.initials: D
authors.lastname: Yanez
authors.forename: Edith
authors.initials: E
authors.lastname: Miller
mesh_terms: D000328:Adult; D001724:Birth Weight; D001786:Blood Glucose / Q000378:metabolism; D015331:Cohort Studies; D016640:Diabetes, Gestational / Q000453:epidemiology*; D005260:Female; D005320:Fetal Macrosomia / Q000453:epidemiology*; D005865:Gestational Age; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008423:Maternal Age; D009657:North Carolina / Q000453:epidemiology; D011247:Pregnancy; D012307:Risk Factors
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human