Table 2.

Summary of studies measuring ADHD

Author and year	Study design	Country	Sample size and age of children at diagnosis	Ascertainment of GDM diagnosis	ADHD measure	Findings [%, mean (SD), OR/HR/RR, β (95% CI)]	Risk of bias score (low–high: 0–2)	Risk of bias
Akaltun et al. 201962	Case control	Turkey	88 children of GDM mothers 128 children of non-diabetic mothers Aged 6–12 years	Medical records and self-report Diagnostic criteria defined by Carpenter-Coustan on 100 g OGTT	Diagnosis from medical records and parental report	GDM group: 15.9% had ADHD Non-GDM group: 7.0% had ADHD p = 0.115	Selection bias: Representativeness: 2 Participation rates: 2 Measurement bias: GDM: 0 ADHD: 0	High
Chiu et al. 200963	Cross-sectional	Taiwan	11 children of GDM mothers 1380 children of non-GDM mothers Aged 4–9 years	Self-report Diagnostic criteria unknown	Symptoms of inattention using child behaviour checklist	OR not significant. No values given	Selection bias: Representativeness: 1 Participation rates: 0 Measurement bias: GDM: 2 ADHD: 2	High
Daraki et al. 201764	Prospective cohort	Greece	55 children of GDM mothers 636 children of non-GDM mothers Aged 4 years	Medical records Diagnostic criteria defined by Carpenter-Coustan on OGTT	Symptoms using attention deficit hyperactivity disorder test (ADHDT)	β: 1.75 (-2.14,5.66) (Adjusted for child sex and age) β: 2.41 (95% CI: -1.45,6.28) (Further adjusted for maternal age, maternal origin, maternal education level, parity and maternal smoking during pregnancy) β: 2.32 ( -1.52,6.16) (Further adjusted for maternal pre-pregnancy BMI)	Selection bias: Representativeness: 0 Participation rates: 1 Measurement bias: GDM: 0 ADHD: 0	Low to moderate
Galera et al. 201865	Prospective cohort	France	84 children of GDM mothers 1158 children of non-diabetic mothers Aged 3–8 years	Medical records or parental interviews Diagnostic criteria unknown	Symptoms by the Strengths and Difficulties Questionnaire	GDM group: 15.5% had high hyperactivity-impulsivity trajectories Non-GDM group: 14.9% had high hyperactivity-impulsivity trajectories	Selection bias: Representativeness: 0 Participation rates: 2 Measurement bias: GDM: 2 ADHD: 2	High
Kong et al. 201829	Prospective cohort (population-based)	Finland	101,696 children of GDM mothers 543,347 children of non-diabetic mothers Aged up to 11 years	Medical records Diagnostic criteria unknown	Diagnosis from medical records	HR separated by BMI: Normal: 1.15 (1.01–1.30) Overweight: 1.16 (1.02- 1.32) Obese: 1.64 (1.42–1.88) Severely obese: 2.15 (1.84–2.52)	Selection bias: Representativeness: 0 Participation rates: 0 Measurement bias: GDM: 1 ADHD: 0	Low to moderate
Li et al. 201658	Prospective cohort	USA	301 children with ADHD 1748 typically developing children Age of children not reported	Medical records Diagnostic criteria unknown	Diagnosis from medical records	4.0% of children with ADHD had mothers with GDM 4.5% of typically developing children had mothers with GDM HR for ADHD in GDM vs no diabetes: 0.99 (0.50–1.94) p = 0.98 HR for ADHD in GDM and obesity vs neither condition: 1.20 (0.49–2.93) p = 0.70	Selection bias: Representativeness: 1 Participation rates: 2 Measurement bias: GDM: 1 ASD: 0	High
Mina et al. 201743	Prospective cohort	UK	14 children of GDM mothers 96 children of non-GDM mothers Aged 3–5 years	Medical records Diagnostic criteria unknown	Symptoms using Conners hyperactivity scale	Mean score for GDM children: 8.7 (6.0)* Mean score for non-GDM children: 7.3 (4.5)*	Selection bias: Representativeness: 2 Participation rates: 2 Measurement bias: GDM: 1 ADHD: 0	High
Nomura et al. 201244	Prospective cohort	USA	21 children of GDM mothers Mean age 4.4 years (SD 0.48) 191 children of non-GDM mothers Mean age 4.3 years (SD 0.47)	Self-report Diagnostic criteria unknown	Diagnosis using a psychiatric interview and symptoms using ADHD rating scale-IV	Mean inattention score at baseline (no standard deviations given): GDM group: 12.25 Non-GDM group: 9.50 p = 0.05 Mean hyperactivity/ impulsivity scores: GDM group: 12.58 Non GDM group: 11.29 p = 0.36 76.2% children exposed to GDM had ADHD* 61.3% children not exposed to GDM had ADHD* OR at baseline: 1.58 (0.77–3.27) p = 0.22 OR at age 6 years: 2.20 (1.00–4.82) p = 0.05	Selection bias: Representativeness: 2 Participation rates: 2 Measurement bias: GDM: 2 ADHD: 0	High
Ornoy et al. 199966	Prospective cohort	Israel	32 children of GDM mothers Mean age 8.5 years (SD 2.1) 57 children of non-diabetic mothers Mean age 8.3 years (SD 1.7)	Medical records Diagnostic criteria: abnormal glucose tolerance test (≥ 190 mg % glucose at 90 min, ≥ 165 mg % at 120 min, ≥ 145 mg % at 180 minutes, or with ≥ 105 mg % fasting glucose blood concentrations)	Symptoms using Conners parents’ questionnaire and Pollack Tapper Test	Conners parents’ questionnaire: Children of GDM mothers had mean score of 8.0 (6.5) if young and 6.8 (6.3) if older Control children had a score of 7.9 (4.3) if young and 7.0 (4.3) if older 4 GDM children had abnormal scores (above 14) compared with only 2 controls. p = 0.06 Pollack general: Children of GDM mothers had a mean score of 19.0 (12.4) if young and 29.6 (10.5) if older Control children had a score of 28.0 (3.2) if young and 30.3 (6.9) if older Pollack’s sound: Children of GDM mothers had a score of 10.6 (6.6) if young and 14.9 (5.0) if older Control children had a score of 14.8 (6.5) if young and 15.6 (3.6) if older Pollack visual Children of GDM mothers had a score of 7.7 (5.9) if young and 14.1 (5.4) if older Control children had a score of 13.2 (2.0) if young and 14.7 (3.4) if older	Selection bias: Representativeness: 2 Participation rates: 0 Measurement bias: GDM: 0 ADHD: 0	High
Pohlabeln et al. 201767	Prospective cohort	Eight European countries	435 children of GDM mothers 18% under 4 years of age, 27% aged 4–6, 38% aged 6–8 and 17% over 8 years of age	Self-report Diagnostic criteria unknown	Diagnosis from parental report	1.8% of children exposed to GDM had ADHD 1.1% of children not exposed to GDM had ADHD OR: 1.42 (0.69–2.95) (adjusted for sociodemographics and country) OR: 1.28 (0.59–2.80) (further adjusted for pre-, peri- and postnatal influences) Unadjusted OR excluding pregestational diabetes: 1.149 (0.468–2.818) * Adjusted OR excluding pregestational diabetes: 1.032 (0.417–2.556) (adjusted for sex, age and country) *	Selection bias: Representativeness: 0 Participation rates: 0 Measurement bias: GDM: 2 ADHD: 1	High
Say et al. 201660	Retrospective cohort	Turkey	100 children with ADHD Mean age 8.8 years (SD 1.98) 80 control children Mean age 8.5 years (SD 4.61)	Self-report Diagnostic criteria unknown	Diagnosis from expert child and adolescent psychiatrist	2% of ADHD group were exposed to GDM 1.3% of control group were exposed to GDM p = 0.717	Selection bias: Representativeness: 2 Participation rates: 2 Measurement bias: GDM: 2 ADHD: 0	High
Schmitt and Romanos 201245	Cross-sectional (population-based)	Germany	280 children of GDM mothers 13,208 children of non-GDM mothers Aged 3–17 years	Self-report Diagnostic criteria unknown	Diagnosis from parental report	8.6% of children of GDM mothers had ADHD 5.1% of children of non-GDM mothers had ADHD Unadjusted OR: 1.93 (1.26–2.95) Adjusted OR: 1.91 (1.21–3.01) (adjusted for child sex, age, socioeconomic position, maternal smoking during pregnancy, maternal alcohol consumption during pregnancy, perinatal health problems, breastfeeding and atopic eczema)	Selection bias: Representativeness: 0 Participation rates: 1 Measurement bias: GDM: 2 ADHD: 1	High
Veena et al. 201032	Prospective cohort	India	32 children of GDM mothers 515 children of non-diabetic mothers Aged 9–10 years	Medical records Diagnostic criteria defined by Carpenter-Coustan on OGTT	Symptoms using Coding-Wechsler Intelligence Scale for Children—3rd Edition (Coding WISC-III) score	Mean score for GDM group: 36.8 (8.0) Mean score for non-GDM group: 32.4 (8.1) p = 0.003 β: 0.4 (0.09–0.75) p = 0.01 (adjusted for child’s sex, gestation and age) β: 0.3 (0.01, 0.67) p = 0.04 (further adjusted for SES, parents’ education and rural/urban residence) β: 0.3 (-0.04, 0.67) p = 0.08 (further adjusted for maternal age, BMI and parity in pregnancy and child’s weight and head circumference at birth)	Selection bias: Representativeness: 0 Participation rates: 0 Measurement bias: GDM: 0 ADHD: 2	High
Wolford et al. 201731	Prospective cohort	Finland	176 children of GDM mothers 1,603 children of non-GDM mothers (9 with T1DM) Mean 3.8 years (SD 0.5)	Medical records Diagnostic criteria unknown	Symptoms using Conners hyperactivity index (CHI)	Mean difference in CHI sum score for GDM vs no GDM: -0.05 (p = 0.08)	Selection bias: Representativeness: 0 Participation rates: 1 Measurement bias: GDM: 1 ADHD: 0	Low to moderate
Xiang et al. 201836	Retrospective cohort	USA	29,534 children of GDM mothers 295,304 children of non-diabetic mothers Age of children not reported	Medical records Diagnostic criteria:  ≥ 200 mg/dL blood glucose on 1 h 50 g glucose challenge test or 3 h 100 g or 2 h 75 g OGTT defined by Carpenter-Coustan criteria	Diagnosis from medical records	4.8% children of GDM mothers diagnosed with ADHD 5.2% children of non-diabetic mothers diagnosed with ADHD HR: 0.94 (0.88–1.00) p = 0.04 (adjusted for random sibling effect and birth year) HR: 1.02 (0.96–1.09) p = 1.50 (further adjusted for maternal age at delivery, parity, education, household income, maternal race/ethnicity, history of comorbidity, history of maternal ADHD and sex of the child) HR: 1.00 (0.94–1.06) (further adjusted for smoking, alcohol and pre-pregnancy BMI) HR: 1.01 (0.95, 1.08) (Adjusted for variables in first multivariate adjusted HR (1.02), plus pre-eclampsia, eclampsia, congenital anomalies, birth weight, and gestational age at delivery)	Selection bias: Representativeness: 1 Participation rates: 0 Measurement bias: GDM: 0 ADHD: 0	Low to moderate

%: percentage, SD standard deviation, OR odds ratio, HR hazard ratio, RR risk ratio, β β coefficient, CI confidence interval.

*Data provided by study author