Table 4.

A summary of glycaemic control and maternal outcomes for different intervention strategies

Intervention strategies	Fasting plasma glucose (mmol/L) after dietary intervention [studies included; total number of participants]	2‐Hour plasma glucose (mmol/L) after dietary intervention [studies included; total number of participants]	HbA1c (%) after dietary intervention [studies included; total number of participants]	Pre‐eclampsiaa [studies included; total number of participants]	Caesarean sectiona [studies included; total number of participants]
Compared to individualised dietary intervention
Food exchange	−0.94 (−1.37, −0.51) [Chen 2017; 118] (RCT) −0.61 (−0.69, −0.53)b [Zhang 2015a; 348] (Cohort study)	−1.26 (−1.73, −0.79) [Chen 2017; 118] (RCT) −0.89 (−1.17, −0.61)b [Zhang 2015a; 348] (Cohort study)	−0.90 (−1.29, −0.51) [Chen 2017; 118] (RCT) −0.98 (−1.12, −0.84)b [Zhang 2015a; 348] (Cohort study)	—	0.93 (0.79, 1.11)4 b [Zhang 2013; Zhang 2015a; 546] (Cohort studies)
Low GI diet	−0.62 (−1.12, −0.13)3 [Hu 2014, Liu 2015, Liu 2018, Wu 2014, Wu 2015; 1038] (RCTs) 0.16 (−0.01, 0.33)b [Wang 2016a; 128] (Cohort study)	−1.19 (−2.29, −0.09)3 [Liu 2015, Liu 2018, Wu 2015; 732] (RCTs) −1.44 (−2.09, −0.79)b [Wang 2016a; 128] (Cohort study)	−1.17 (−1.85, −0.49)4 [Liu 2018, Wu 2014, Wu 2015; 380] (RCTs) −0.15 (−0.35, 0.05)b [Wang 2016a; 128] (Cohort study)	0.72 (0.23, 2.24) [Liu 2015; 518] (RCT)	0.70 (0.45, 1.08)3 [Liu 2015, Wu 2014; 684] (RCTs)
Low GL diet	−2.00 (−3.33, −0.67)4 [Gai 2012, Jiang 2016, Li 2017, Ma 2015, Zhang 2015; 489] (RCTs)	−3.12 (−4.91, −1.32)4 [Gai 2012, Jiang 2016, Ma 2015, Zhang 2015; 375] (RCTs)	−1.06 (−2.01, −0.10)4 [Gai 2012, Jiang 2016, Li 2017, Ma 2015, Zhang 2015; 489] (RCTs)	—	0.21 (0.05, 0.95) [Li 2017; 114] (RCT)
Fibre‐enriched diet	−0.42 (−0.79, −0.04)3 [Lian 2014, Luo 2016, Pan 2015, Yang 2015; 624] (RCTs) −0.90 (−1.49, −0.31)b [Wu 2010; 105] (Cohort study)	−1.40 (−2.30, −0.50)3 [Lian 2014, Luo 2016, Pan 2015, Yang 2015; 624] (RCTs) −1.20 (−1.92, −0.48)b [Wu 2010; 105] (Cohort study)	−0.61 (−1.07, −0.14)3 [Lian 2014, Luo 2016, Yang 2015; 528] (RCTs)	—	—
DASH diet	−0.66 (−0.80, −0.51) [Yao 2015; 33] (RCT)	—	—	—	0.58 (0.33, 1.01) [Yao 2015; 33] (RCT)
PUFA‐rich diet	0.18 (−0.17, 0.53) [Wang 2015; 84] (RCT)	−0.02 (−0.29, 0.25) [Wang 2015; 84] (RCT)	—	—	—
Compared to food exchange intervention
Low GI diet	0.20 [−0.00, 0.40] [Wang 2016; 64] (RCT)	−0.70 (−1.74, 0.34) [Wang 2016; 64] (RCT)	−0.20 (−0.65, 0.25) [Wang 2016; 64] (RCT)	—	0.74 (0.40, 1.37) [Wang 2016; 64] (RCT)
Low GL diet	−0.36 (−0.66, −0.07)3 [Chen 2015, Huang 2015, Sun 2013, Wang 2016, Wu 2013, Zhi 2012; 552] (RCTs) −0.10 (−0.47, 0.27)b [Shen 2010; 80] (Cohort study)	−1.05 (−1.54, −0.56)3 [Chen 2015, Huang 2015, Sun 2013, Wang 2016, Wu 2013, Zhi 2012; 552] (RCTs) −1.10 (−1.78, −0.42)b [Shen 2010; 80] (Cohort study)	−0.50 (−0.88, −0.12) [Wang 2016; 64] (RCT) −0.20 (−0.49, 0.09)b [Shen 2010; 80] (Cohort study)	0.45 (0.04, 4.79)b [Shen 2010; 80] (Cohort study)	0.68 (0.36, 1.28)4 [Wang 2016, Zhi 2012; 109] (RCTs)

^aDichotomous outcomes expressed in relative risks (95% confidence interval).

^bResults from cohort studies.

DASH, Dietary Approaches to Stop Hypertension; GI, glycaemic index; GL, glycaemic load; PUFA, polyunsaturated fatty acid; LGA, large for gestational age; NICU, neonatal intensive care unit admission; SGA, small for gestational age.

Continuous outcomes expressed in weighted mean differences (95% confidence interval).

The quality of evidence of each outcome from two or more studies was assessed using GRADE and was presented as number superscript after each outcome in the level of quality of evidence of: ¹high, ²moderate, ³low and ⁴very low.