Table 2.

Odds of gestational diabetes (GDM) according to HbA_1c level at 8–13 weeks and the change in HbA_1c from 8–13 weeks and 16–22 and 24–29 weeks, NICHD Fetal Growth Studies- Singletons (2009–2013).

	Crude Modelb		Adjusted Modelb,c
	OR (95% CI)	P	OR (95% CI)	P
HbA1c at Visit 0a
Per 0.1%	1.27 (1.14, 1.40)	<0.001	1.22 (1.09, 1.36)	<0.001
Change in HbA1c from visit 0 to 1a
Per 0.1%	1.10 (0.95, 1.16)	0.19	1.04 (0.90, 1.21)	0.57
Change in HbA1c from visit 0 to 2a
Per 0.1%	1.21 (1.01, 1.44)	0.03	1.21 (1.01, 1.45)	0.04

Abbreviations: CI, confidence interval.

^aVisit 0: 8–13 weeks. Visit 1: 16–22 weeks. Visit 2: 24–29 weeks.

^bNon-GDM controls matched to each GDM case on maternal age (±2 years), race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, Asian/Pacific Islander), and gestational week of blood collection (±2 weeks). Models additional adjusted for maternal age and gestational age at delivery to remove any remaining residual confounding with these factors.

^cModel additionally adjusted for family history of diabetes and pre-pregnancy overweight and obesity.