The Effects of Serum Folic Acid and Vitamin B12 on the Risk of Gestational Diabetes Mellitus

Figures & data

Table 1 Demographic Characteristics and Clinical Outcomes of Maternal with GDM and Control Group

Variables	GDM	Control Group	χ^2	P
	N (%)	N (%)
Age (years)			15.3998	0.0005
<30	39(13.13)	258(86.87)
30−34	88(25.51)	257(74.49)
≥35	20(19.61)	82(80.39)
Median (P25, P75)	31(29.33)	30(28.33)	−	0.0002
Pre−pregnancy BMI			23.0287	<0.0001
<18.5	10(7.94)	116(92.06)
18.5−23.9	89(19.35)	371(80.65)
24−27.9	33(28.95)	81(71.05)
≥28	12(36.36)	21(63.64)
Median (P25, P75)	22(20.24)	21(19.23)	−	<0.0001
Gravidity			0.8980	0.6383
1	62(18.67)	270(81.33)
2	52(21.76)	187(78.24)
≥3	33(19.08)	140(80.92)
Family history of diabetes			8.8858	0.0029
No	135(18.88)	580(81.12)
Yes	12(41.38)	17(58.62)
Total	147 (19.76)	597 (80.24)	−	−

Notes: Continuous variables were presented as medium (P25, P75); categorical variables were presented with count (percentage).

Table 2 The Interquartile Ranges of Serum Folic Acid/Vitamin B12 in GDM and Control Group

Variables	GDM	Control Group	χ^2	P
	N (%)	N (%)
Folic acid (ng/mL)			4.1178	0.2490
Q1 (<10.77)	38(20.54)	147(79.46)
Q2 (10.77−14.10)	36(19.25)	151(80.75)
Q3 (14.11−19.10)	29(15.51)	158(84.49)
Q4 (≥19.11)	44(23.78)	141(76.22)
Median (P25, P75)	13.98(10.48, 21.66)	14.11(10.81, 18.51)	−	0.9267
Vitamin B12 (pg/mL)			18.2443	0.0004
Q1 (<265.40)	56(29.79)	132(70.21)
Q2 (265.40−334.69)	37(20.00)	148(80.00)
Q3 (334.70−405.79)	27(14.59)	158(85.41)
Q4 (≥405.80)	27(14.52)	159(85.48)
Median (P25, P75)	306.10(230.30, 390.50)	341.70(277.45, 410.60)	−	0.0015

Notes: Continuous variables were presented as medium (P25, P75); categorical variables were presented with count (percentage).

Table 3 Multivariable Analyses on the Relationships Between Serum Folic Acid/Vitamin B12 and the Risk of GDM

Variables	Total		Stratified by Age		Stratified by BMI
	Model 1	Model 2^a	Model 3^b	Model 4^b	Model 5^c	Model 6^c
	OR(95% CI)	OR(95% CI)	OR(95% CI) (Age<30)	OR(95% CI) (Age≥30)	OR(95% CI) (BMI<24)	OR(95% CI) (BMI≥24)
Folic acid (ng/mL)
Q1	1.41(0.83, 2.40)	1.47(0.85, 2.56)	1.86(0.63, 5.50)	1.29(0.67, 2.49)	1.53(0.79, 2.99)	1.14(0.42, 3.07)
Q2	1.30(0.76, 2.22)	1.25(0.71, 2.19)	1.64(0.53, 5.07)	1.12(0.58, 2.15)	1.66(0.86, 3.21)	0.59(0.21, 1.66)
Q3	Ref	Ref	Ref	Ref	Ref	Ref
Q4	1.70(1.01, 2.86)	1.84(1.07, 3.16)	2.33(0.78, 6.90)	1.74(0.92, 3.30)	2.09(1.11, 3.93)	1.03(0.35, 3.06)
P for trend	0.6499	0.5560	0.8923	0.3931	0.5378	0.9299
Vitamin B12 (pg/mL)
Q1	2.48(1.49, 4.15)	2.14(1.26, 3.65)	4.76(1.45, 15.61)	1.71(0.92, 3.15)	2.24(1.22, 4.14)	2.28(0.78, 6.67)
Q2	1.46(0.85, 2.52)	1.45(0.83, 2.53)	2.93(0.87, 9.82)	1.11(0.58, 2.12)	1.33(0.70, 2.51)	1.87(0.58, 5.98)
Q3	Ref	Ref	Ref	Ref	Ref	Ref
Q4	0.99(0.56, 1.77)	0.99(0.55, 1.79)	1.11(0.28, 4.42)	1.05(0.54, 2.05)	1.01(0.52, 1.96)	0.89(0.24, 3.26)
P for trend	<0.0001	0.0015	0.0018	0.1043	0.0060	0.0438

Notes: ^aAdjusted for age, BMI, gravidity, and family history of diabetes. ^bAdjusted for BMI, gravidity, and family history of diabetes. ^cAdjusted for age, gravidity, and family history of diabetes; bold represent for P < 0.05.

Figure 1 The associations between serum folic acid/vitamin B12 and GDM risk by RCS regression analysis. (A) The association between serum folic acid and GDM; (B) the association between vitamin B12 and GDM. Adjusted for age, BMI, gravidity, and family history of diabetes.