| Validation study | Reproducibility study (n = 58) | |||||||
---|---|---|---|---|---|---|---|---|---|
 | All participants (n = 167) | S Hospital (n = 76) | T Hospital (n = 91) |  |  |  | |||
 | Mean ± SD or n (%) | Mean ± SD or n (%) | Mean ± SD or n (%) | p 1 | Mean ± SD or n (%) | ||||
Age [years] | 32.4 ± 4.9 | 30.5 ± 5.0 | 34.1 ± 4.1 | < 0.001 | 33.8 ± 4.2 | ||||
Parity: Primigravida [n (%)] | 80 | (48) | 34 | (45) | 46 | (51) | ns | 38 | (66) |
Currently married [n (%)] | 166 | (99) | 75 | (99) | 91 | (100) | ns | 58 | (100) |
Education [n (%)] | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   < 13 years | 32 | (19) | 25 | (33) | 7 | (8) | < 0.001 | 3 | (5) |
   13-15 years | 75 | (45) | 37 | (49) | 38 | (42) |  | 24 | (41) |
   > 15 years | 60 | (36) | 14 | (18) | 46 | (51) |  | 31 | (53) |
Household income (Japanese yen/year) [n (%)] | Â | Â | Â | Â | Â | Â | Â | Â | Â |
   < 5,000,000 | 59 | (35) | 38 | (50) | 21 | (23) | < 0.001 | 7 | (12) |
   5,000,000-9,000,000 | 70 | (42) | 32 | (42) | 38 | (42) |  | 27 | (47) |
   > 9,000,000 | 38 | (23) | 6 | (8) | 32 | (35) |  | 24 | (41) |
Height [cm] | 158.7 ± 5.7 | 157.8 ± 5.2 | 159.5 ± 5.9 | 0.048 | 159.1 ± 5.4 | ||||
Prepregnancy BMI2 [kg/m2] | 20.5 ± 2.3 | 20.6 ± 2.3 | 20.3 ± 2.4 | ns | 20.2 ± 3.0 | ||||
   BMI < 18.5 [n (%)] | 28 | (17) | 8 | (11) | 20 | (22) | ns | 17 | (29) |
   18.5 ≤ BMI < 25.0 [n (%)] | 131 | (78) | 65 | (86) | 66 | (73) |  | 38 | (65) |
   BMI ≥ 25.0 [n (%)] | 8 | (5) | 3 | (4) | 5 | (6) |  | 3 | (5) |
Working [n (%)] | 66 | (40) | 21 | (28) | 45 | (50) | 0.004 | 22 | (38) |
Regular smoker during pregnancy [n (%)] | 3 | (2) | 1 | (1) | 2 | (2) | ns | 1 | (2) |
Regular alcohol drinker during pregnancy [n (%)] | 5 | (3) | 2 | (3) | 3 | (3) | ns | 2 | (3) |
Nausea during the study period [n (%)] | 46 | (28) | 15 | (20) | 31 | (34) | 0.039 | 10 | (17) |
Gestational age [weeks] | 22.6 ± 2.8 | 25.4 ± 1.0 | 20.3 ± 1.2 | < 0.001 |  |  | |||
Gestational age at first survey [weeks] |  |  |  |  |  |  |  | 16.9 ± 1.5 | |
Gestational age at second survey [weeks] |  |  |  |  |  |  |  | 21.0 ± 1.3 |