Table 3.

Subgroup analysis: Univariable and multivariable logistic regression analysis of factors potentially associated with GDM during the subsequent pregnancy.

	Subgroup1: GDM during the index pregnancy								Subgroup2: Non-GDM during the index pregnancy
	n = 70								n = 1,570
	N	n/N	cOR	95%CI	p-value	aOR	95%CI	p-value	N	n/N	cOR	95%CI	p-value	aOR	95%CI	p-value
	(%)	(%)							(%)	(%)
Maternal age ≥ 35 years☨	17	14/17	2.61	(0.66-10.24)	0.170	1.86	(0.41-8.41)	0.423	290	20/290	1.00	(0.61-1.66)	0.990	1.00	(0.59-1.67)	0.990
	(24.3)	(82.4)							(18.5)	(6.9)
Pre-pregnancy BMI ≥ 25.0☨	23	20/23	4.52	(1.18-17.38)	0.028*	5.83	(1.33-25.52)	0.019*	116	17/116	2.57	(1.47-4.49)	<0.001*	2.28	(1.28-4.04)	0.005*
	(32.9)	(87.0)							(7.4)	(14.7)
Insulin use☨	21	19/21	6.55	(1.37-31.32)	0.019*	6.98	(1.38-35.38)	0.019*	0	–	–	–	–	–	–	–
	(30.0)	(90.5)							(0.0)
Macrosomia☨§	2	2/2	–	–	–	–	–	–	17	3/17	2.96	(0.84-10.45)	0.093	1.99	(0.53-7.46)	0.305
	(2.9)	(100)							(1.1)	(17.6)
Pregnancy interval, years	–	–	1.03	(0.69-1.54)	0.893	1.16	(0.75-1.79)	0.513	–	–	1.07	(0.88-1.31)	0.493	1.13	(0.92-1.37)	0.241
Anuual BMI change, kg/m2/year	–	–	1.00	(0.64-1.58)	0.986	1.10	(0.60-2.01)	0.765	–	–	1.60	(1.30-1.98)	<0.001*	1.57	(1.27-1.95)	<0.001*
High parity (Parity ≥ 2)§	15	15/15	–	–	–	–	–	–	350	23/350	0.94	(0.58-1.51)	0.797	0.93	(0.57-1.50)	0.755
	(21.4)	(100)							(22.3)	(6.6)

N: The number of patients for each variables; n/N: The number of GDM events during the subsequent pregnancy/N; cOR, clude odds ratio; aOR, adjusted odds ratio; CI, confidence interval; BMI, body mass index; GDM, gestational diabetes mellitus.

^☨Parameteres of the index pregnancy. ^§ORs were not calculated because there were no non-GDM during the subsequent pregnancy in subgroup1. *Statistically significant.