Role of fasting glucose and glycated hemoglobin for gestational diabetes mellitus diagnosis: A prospective study

Table 1 Contingency table

Alternative criteria	100-g OGTT
	Positive	Negative	Total
Positive	20	24	44
Negative	60	250	310
Total	80	274	354

OGTT: Oral glucose tolerance test.

Table 2 Comparison between study groups regarding clinical characteristics and obstetric and perinatal outcomes

Parameter	OGTT+/A+ (n = 20)	OGTT+/A- (n = 54)	OGTT-/A+ (n = 21)	OGTT-/A- (n = 234)	P value
Age (years)	33.1 ± 4.2	33.7 ± 5.5	33.7 ± 5.1	33.8 ± 5.1	0.959
Pregestational BMI (kg/m2)	30.1 ± 6.3c	26.8 ± 5.1b	32.7 ± 5.3a,c	25.6 ± 5.0b,d	< 0.001
Pregestational obesity prevalence (%)	40.0	28.3	70.8	18.0	< 0.001
Pregnancy weight gain (kg)	5.5 ± 5.8	6.4 ± 5.6	5.2 ± 6.5	6.3 ± 4.3	0.666
Past pregnancies (%)	80.0	57.6	58.3	59.6	0.320
Previous abortions (%)	30.0	37.3	37.5	37.8	0.924
Family history on DM (%)	30.0	36.7	37.5	39.6	0.842
Personal history GDM (%)	36.8	25.0	22.2	15.2	0.088
Previous macrosomic newborns (%)	21.1	0	16.7	7.3	0.016
Risk of GDM (%)	22.5 ± 23.4a	14.6 ± 18.4b	16.7 ± 14.6a,b	10.1 ± 12.4c	< 0.001
O’Sullivan test (mg/dL)	183.3 ± 32.1a,b,c	168.3 ± 21.1c,d	165.9 ± 29.8d	156.9 ± 14.7a,d	< 0.001
Gestational age at 100-g OGTT (weeks)	25.9 ± 4.9	26.3 ± 3.7	25.0 ± 6.2	25.5 ± 4.6	0.541
FPG (mg/dL)	106.3 ± 14.4a,b,c	83.5 ± 6.4b,d	94.3 ± 6.7a,c,d	81.3 ± 5.7b,d	< 0.001
60 minutes glucose (mg/dL)	206.6 ± 39.5b,c	193.8 ± 26.1b,c	166.2 ± 25.2a,d	154.4 ± 26.8a,d	< 0.001
120 minutes glucose (mg/dL)	186.7 ± 28.2b,c	179.1 ± 20.5b,c	146.7 ± 20.0a,c,d	129.3 ± 24.4a,b,d	< 0.001
180 minutes glucose (mg/dL)	142.3 ± 27.9b,c	139.5 ± 32.8b,c	113.6 ± 24.2a,d	105.4 ± 27.1a,d	< 0.001
HbA1c (%)	5.6 ± 0.4a,c	5.1 ± 0.2b,c,d	5.5 ± 0.3a,c	5.0 ± 0.2a,b,d	< 0.001
Gestational age at delivery (weeks)	38.8 ± 1.2	38.8 ± 1.2	38.7 ± 1.9	38.9 ± 1.7	0.957
Preterm birth (%)	5.0	3.7	4.8	6.0	0.925
Birthweight (g)	3326.7 ± 528.2a,c	3157.8 ± 397.9d	3505.8 ± 592.0	3221.7 ± 493.9d	0.001
Birthweight percentile	72.6 ± 27.3a,c	46.8 ± 28.2b,d	72.3 ± 23.7a	52.9 ± 28.8d	< 0.001
SGA/LGA (%)	5.0/35.0	9.2/11.1	0/28.6	6.4/13.7	0.028
Birth length (cm)	51.2 ± 2.0a	49.2 ± 3.3d	50.6 ± 2.4	50.0 ± 2.4	0.033
Head circumference (cm)	34.4 ± 1.5	33.5 ± 1.5	34.0 ± 1.9	33.5 ± 1.6	0.175
Sex of newborn					0.837
Female (%)	50.0	51.0	41.2	45.0
Male (%)	50.0	49.0	58.8	55.0
Induction of labor (%)	30.0	27.7	33.3	22.6	0.789
Type of delivery					0.223
Noninstrumental vaginal (%)	31.6	66.0	52.9	52.6
Instrumental (%)	10.5	8.0	11.8	13.1
Cesarean (%)	57.9	26.0	35.3	34.3
Any perinatal complication (%)	25.0	17.3	14.3	13.2	0.503

^aP < 0.05 vs oral glucose tolerance test+/alternative diagnostic- according to an ANOVA followed by Tukey’s test post.

^bP < 0.05 vs oral glucose tolerance test-/alternative diagnostic+ according to an ANOVA followed by Tukey’s test post.

^cP < 0.05 vs oral glucose tolerance test-/alternative diagnostic- according to an ANOVA followed by Tukey’s test post.

^dP < 0.05 vs oral glucose tolerance test+/alternative diagnostic according to an ANOVA followed by Tukey’s test post according to an ANOVA followed by Tukey’s test post.

A: Alternative diagnostic; BMI: Body mass index; DM: Diabetes mellitus; FPG: Fasting plasma glucose; GDM: Gestational diabetes mellitus; HbA1c: Glycated hemoglobin; LGA: Large for gestational age; OGTT: Oral glucose tolerance test; SGA: Small for gestational age.

Table 3 Univariate and multivariate logistic regression analysis for large for gestational age newborns

Independent variables	Univariate			Multivariate
	OR	95%CI	P value	OR	95%CI	P value
Age (years)	0.995	0.938-1.056	0.877
Gestational age at test (weeks)	1.044	0.971-1.123	0.245
Parity
Primigravida	1 (reference)
Multigravida	1.860	0.956-3.610	0.066
OGTT status			0.631
OGTT negative	1 (reference)
OGTT positive	1.183	0.592-2.374
A criteria status			0.001
A negative	1 (reference)
A positive	4.291	1.814-10.153
Pregestational BMI (kg/m2)	1.071	1.016-1.128	0.010	1.069	1.002-1.140	0.042
Pregnancy weight gain (kg)	1.068	1.002-1.138	0.042
Personal history of GDM			0.224
No	1 (reference)
Yes	1.826	0.692-4.819
Previous macrosomic newborns			0.001
No	1 (reference)			1 (reference)
Yes	6.897	2.183-21.788		7.948	2.269-27.842	0.001
FPG (mg/dL)	1.065	1.025-1.108	0.001
HbA1c (%)	1.745	0.654-4.653	0.266
Treatment for GDM			0.521
Diet	1 (reference)
Insulin	1.507	0.431-5.273

A: Alternative diagnostic; BMI: Body mass index; 95%CI: 95% confidence interval; GDM: Gestational diabetes mellitus; HbA1c: Glycated hemoglobin; OGTT: Oral glucose tolerance test; OR: Odds ratio.