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Table 1 Summary of characteristics of non-T1D and T1D pregnancies

From: Type 1 diabetes in pregnancy is associated with distinct changes in the composition and function of the gut microbiome

General Non-T1D T1D P value**
Overall number of samples: n (%) 66 (49.3) 68 (50.7)  
 Trimester 1 11 (16.7) 12 (17.6)  
 Trimester 2 21 (31.8) 22 (32.4)  
 Trimester 3 34 (51.5) 34 (50.0)  
 All three trimesters (% pregnancies) 12 (35.3) 12 (33.3)  
 All three trimesters (% samples) 12 (18.2) 12 (18.2)  
 Gestational age in days at fecal sample: mean (SD)
  Trimester 1 75.4 (16.5) 75.3 (16.5)  
  Trimester 2 150.8 (26.6) 148.4 (26.6)  
  Trimester 3 247.6 (14.6) 234.7 (14.6) 0.001
Maternal
 Overall number of pregnancies 34 36  
 Age in years at conception: mean (SD) 33 (4.1) 32.3 (4.0)  
 Paternal missing n (%) 1 (2.9) 2 (5.6)  
 Assisted conception: n (%) 3 (8.8) 4 (11.1)  
 Twin pregnancy: n (%) 0 (0.0) 0 (0.0)  
 Nulliparous: n (%) 14 (41.2) 18 (50.0)  
 Pre-eclampsia: n (%) 0 (0.0) 4 (11.1) 0.018
 Group B Streptococcus positive: n (%) 7 (20.6) 1 (2.8)  
 Genito-urinary infections: n (%) 2 (5.9) 5 (13.9)  
 Pre-pregnancy BMI: mean (SD) 24.7 (4.8) 25.8 (4.7)  
 Underweight (< 18.5): n (%) 0 (0.0) 0 (0.0)  
 Normal weight (18.5–24.9): n (%) 21 (61.8) 18 (50.0)  
 Overweight weight (25–29.9): n (%) 6 (17.6) 10 (27.8)  
 Obese (> 30): n (%) 7 (20.6) 8 (22.2)  
 Gestational weight gain (kg): Mean (SD) 13 (5.0) 11.5 (4.9)  
 Gestational weight gain (kg): n (%) 2 (5.9) 2 (5.6)  
Paternal
 Age in years at conception: mean (SD) 34.8 (5.2) 32.7 (4.8) 0.093
 Pre-pregnancy BMI: mean (SD) 28.6 (4.3) 27.6 (4.3)  
 Underweight (BMI < 18.5): n (%) 0 (0.0) 1 (2.8)  
 Normal weight (BMI18.5–24.9): n (%) 4 (11.8) 6 (16.7)  
 Overweight (BMI 25–29.9): n (%) 10 (29.4) 8 (22.2)  
 Obese (> 30): n (%) 6 (17.6) 9 (25.0)  
 Missing: n (%) 14 (41.2) 12 (33.3)  
Maternal demographics
 Born in Australia: n (%)
  Yes 30 (88.2) 24 (66.7)  
  Unknown 0 (0.0) 1 (2.8)  
 Education beyond high school: n (%)
  Yes 30 (88.2) 29 (80.6)  
  Unknown 0 (0.0) 0 (0.0)  
 Lives in a metro area: n (%) 31 (91.2) 35 (97.2)  
 Socio-Economic Indexes for Areas (SEIFA) Index of Relative Socio-Economic Disadvantage (IRSD)
  Quintile 1 n (%) 2 (5.9) 1 (2.8)  
  Quintile 2 n (%) 2 (5.9) 3 (8.3)  
  Quintile 3 n (%) 13 (38.2) 8 (22.2)  
  Quintile 4 n (%) 4 (11.8) 9 (25.0)  
  Quintile 5 n (%) 13 (38.2) 15 (41.7)  
 Smoking during pregnancy: n (%) 3 (8.8) 0 (0.0)  
 Household smoking during pregnancy: n (%) 5 (14.7) 6 (16.7)  
 Adults in house during pregnancy: n (%)
  One 0 (0.0) 2 (5.6)  
  Two 31 (91.2) 29 (80.6)  
 More than two 3 (8.8) 5 (13.9)  
 Children in house during pregnancy: n (%)
  None 14 (41.2) 18 (50.0)  
  One 8 (23.5) 10 (27.8)  
  Two 5 (14.7) 7 (19.4)  
  More than two 7 (20.6) 1 (2.8)  
 Furred pet ownership during pregnancy: n (%) 24 (70.6) 20 (55.6)  
Diet and physical activity in pregnancy
 Diet: mean (SD)
  Energy/day (kJ) 6617.3 (2277.5) 6445.6 (2185.9)  
  Fat (g) 68.8 (27.0) 71.7 (26.8)  
  Protein (g) 77.1 (29.9) 80.3 (29.6)  
  Carbohydrate (g) 163.8 (57.9) 142.4 (52.6)  
  Fibre (g) 18.4 (6.1) 17.9 (5.9)  
 Diet: Missing: n (%) 0 (0.0) 2 (5.6)  
 Alcohol consumed: n (%)
  Yes 6 (17.6) 7 (19.4)  
  Unknown 0 (0.0) 2 (5.6)  
 Metabolic equivalent of task (MET) (h/wk): mean (SD) 254.5 (100.9) 267.9 (102.2)  
Biological data
 HbA1c (%)
  Trimester 1: median (IQR) 6.8 (1.6)  
  Trimester 2: median (IQR) 6.1 (1.3)  
  Trimester 3: median (IQR) 6.1 (0.8)  
  Trimester 1: missing 1 (8.3)  
  Trimester 2: missing 3 (13.6)  
  Trimester 3: missing 14 (41.2)  
 1,5-anhydroglucitol (AG) (μg/mL)
  Trimester 1: median (IQR) 14.1 (13.1) 3.4 (1.5)  
  Trimester 2: median (IQR) 11.5 (4.9) 2.5 (2.3)  
  Trimester 3: median (IQR) 8.1 (6.3) 2.4 (1.3)  
  Trimester 1: mean (SD) 14.1 (5.9) 3.4 (2.9) < 0.001
  Trimester 2: mean (SD) 11.2 (5.1) 2.3 (2.2) < 0.001
  Trimester 3: mean (SD) 8.7 (3.8) 2.4 (2.0) < 0.001
  Trimester 2: missing n (%) 1 (4.8) 1 (4.5)  
  Trimester 3: missing n (%) 2 (5.9) 8 (23.5)  
 Serum vitamin D (nmol/L): mean (SD)
  Trimester 1 83 (26.9) 76.7 (25.8)  
  Trimester 2 96.7 (27.0) 85.5 (24.5)  
  Trimester 3 92.9 (31.6) 96.4 (29.9)  
  Trimester 1: missing n (%) 0 (0.0) 1 (8.3)  
  Trimester 3: missing n (%) 2 (5.9) 3 (8.8)  
 Vitamin B6 (nmol/L): mean (SD)
 Trimester 3 76 (75.8) 70 (102.4)  
 Vitamin B12 (nmol/L): mean (SD)
 Trimester 3 84 (116) 154 (138)  
 Maternal HLA: n (%)
  DR34 3 (8.8) 14 (38.9)  
  DR3 or DR4 20 (58.8) 19 (52.8)  
  DRXX 11 (32.4) 3 (8.3) 0.002
Known supplements in pregnancy
 Antibiotics: n (%) 9 (26.5) 10 (27.8)  
 Anticoagulants: n (%) 3 (8.8) 6 (16.7)  
 Antihypertensive agents: n (%) 0 (0.0) 4 (11.1)  
Known other supplements pre-pregnancy and pregnancy
 Biotin: n (%) 12 (35.3) 9 (25.0)  
29 (85.3) 30 (83.3)
 Calcium: n (%) 13 (38.2) 10 (27.8)  
30 (88.2) 33 (91.7)
 Iron 14 (41.2) 9 (25.0)  
32 (94.1) 35 (97.2)
 Magnesium: n (%) 14 (41.2) 9 (25.0)  
31 (91.2) 32 (88.9)
 Selenium: n (%) 12 (35.3) 9 (25.0)  
29 (85.3 30 (83.3)
 Vitamin B1: n (%) 14 (41.2) 9 (25.0)  
32 (94.1) 32 (88.9)
 Vitamin B2: n (%) 14 (41.2) 9 (25.0)  
31 (91.2) 32 (88.9)
 Vitamin B3: n (%) 14 (41.2) 9 (25.0)  
31 (91.2) 32 (88.9)
 Vitamin B5: n (%) 9 (26.5) 6 (16.7)  
18 (52.9) 16 (44.4)
 Vitamin B6: n (%) 14 (41.2) 9 (25.0)  
32 (94.1) 32 (88.9)
 Vitamin B9 (folate): n (%) 14 (41.2) 15 (41.7)  
32 (94.1) 36 (100.0)
 Vitamin B12: n (%) 14 (41.2) 9 (25.0)  
32 (94.1) 30 (83.3)
 Vitamin D: n (%) 14 (41.2) 10 (27.8)  
33 (97.1) 33 (91.7)
 Vitamin E: n (%) 13 (38.2) 8 (22.2)  
28 (82.4) 27 (75.0)
Other
 Vaccine: n (%)
  Yes (Flu only) 1 (2.9) 3 (8.3)  
  Yes (Pertussis only) 3 (8.8) 3 (8.3)  
  Yes (Flu and Pertussis) 11 (32.4) 10 (27.8)  
 Mode of delivery: n (%)
  Vaginal 25 (73.5) 14 (38.9)  
  Caesarean (with labour) 1 (2.9) 4 (11.1)  
  Caesarean (without labour) 8 (23.5) 18 (50.0) 0.011
  1. Log transformation was used for age at conception: Paternal
  2. Square root transformation was used for all diet variables except carbohydrate and fibre
  3. Square root transformation was used for 1,5-AG in all trimesters and for vitamin D in trimester 2
  4. Hb1A-c, 1,5-AG and vitamin D are based on samples, not pregnancies
  5. NM not measured
  6. ** Blank cells indicate P value non-significant. P values for HLA are determined against DRXX as baseline