Table 1 Characteristics of sample stratified by educational level
Characteristics | All (n= 923) | Low (n=228)* | Mid (n=228)* | High (n=467)* | Pvalue |
|---|---|---|---|---|---|
Maternal age (yrs) | 33.7 (4.1) | 33.4 (4.7) | 34.1 (4.1) | 33.6 (3.8) | NS |
Pre-pregnancy BMI (kg/m2) | 20.2 (2.3) | 21.0 (2.9) | 20.1 (2.2) | 19.8 (2.0) | <0.0001 |
BMI>25, n(%) | 41 (4.4) | 19 (8.3) | 10 (4.4) | 12 (2.6) | <0.05 |
BMI>30, n(%) | 3 (0.3) | 2 (0.9) | 1 (0.4) | 0 (0) | NS |
Parity | |||||
0, n(%) | 452 (49.0) | 97 (42.5) | 104 (45.6) | 251 (53.8) | <0.0001 |
≧1, n(%) | 471 (51.0) | 131 (57.5) | 124 (54.4) | 216 (46.2) | |
Mean gestational age before 16 weeks blood pressure | 14.3 (0.98) | 14.3 (0.98) | 14.3 (0.98) | 14.3 (1.0) | NS |
Mean gestational age at 20 weeks blood pressure | 20 (1.2) | 19.9 (1.2) | 20.1 (1.2) | 20.0 (1.1) | NS |
Maternal pre-pregnancy complications | |||||
Diabetes mellitus, n(%) | 5 (0.5) | 3 (1.3) | 1 (0.44) | 1 (0.21) | NS |
Hypertension, n(%) | 5 (0.5) | 0 (0.0) | 4 (1.8) | 1 (0.21) | <0.05 |
Renal disease, n(%) | 4 (0.4) | 1 (0.4) | 1 (0.44) | 2 (0.43) | NS |
Pre-pregnancy complications | |||||
PIH, n(%) | 11 (1.2) | 4 (1.8) | 1 (0.44) | 6 (1.3) | NS |
Family History | |||||
Diabetes mellitus, n(%) | 72 (7.8) | 14 (6.1) | 19 (8.3) | 39 (8.4) | NS |
Hypertension, n(%) | 69 (7.5) | 13 (5.7) | 14 (6.1) | 42 (9.0) | NS |
Smoking | |||||
Never or former, n(%) | 891 (96.9) | 209 (92.5) | 224 (98.7) | 458 (98.1) | <0.001 |
Current, n(%) | 29 (3.2) | 17 (7.5) | 3 (1.3) | 9 (1.9) | |
Income (per year), n(%) | |||||
<4 million yen | 49 (5.7) | 23 (10.6) | 10 (4.8) | 16 (3.7) | <0.001 |
<6 million yen | 199 (23.2) | 78 (35.9) | 50 (24.2) | 71 (16.4) | |
<8 million yen | 189 (22.1) | 56 (25.8) | 47 (22.7) | 86 (19.9) | |
<10 million yen | 185 (21.6) | 34 (15.7) | 44 (21.3) | 107 (24.7) | |
over 10 million yen | 235 (27.4) | 26 (12.0) | 56 (27.1) | 153 (35.3) | |
Salt Intake | |||||
low, n(%) | 302 (34.1) | 81 (37.7) | 66 (30.0) | 155 (34.3) | NS |
moderate, n(%) | 295 (33.3) | 65 (30.2) | 72 (32.7) | 158 (35.0) | |
high, n(%) | 290 (32.7) | 69 (32.1) | 82 (37.3) | 139 (30.8) | |
Alcohol Intake | |||||
None or former, n(%) | 749 (84.4) | 183 (85.1) | 192 (87.3) | 374 (82.7) | NS |
Current, n(%) | 138 (15.6) | 32 (14.9) | 28 (12.7) | 78 (17.3) | |
Body weight gain until midpregnancy (kg) | 3.4 (2.5) | 3.9 (2.9) | 2.9 (2.6) | 3.4 (2.2) | <0.001 |