Table 1 Characteristics of participants by smoking status during pregnancy.
Male | Female | |||||||
|---|---|---|---|---|---|---|---|---|
Q1: non-smokers (n = 1,512, 62.0%) | Q2: ex-smokers who quit before pregnancy (n = 580, 23.8%) | Q3: ex-smokers who quit during pregnancy (n = 261, 10.7%) | Q4: current smokers (n = 84, 3.4%) | Q1: non-smokers (n = 1454, 61.7%) | Q2: ex-smokers who quit before pregnancy (n = 575, 24.4%) | Q3: ex-smokers who quit during pregnancy (n = 244, 10.4%) | Q4: current smokers (n = 84, 3.6%) | |
Mean ± SD, or number and % in parenthesis | ||||||||
Pre-pregnancy BMI (kg/m2) | ||||||||
Underweight (< 18.5) | 251 (16.6) | 88 (15.2) | 33 (12.6) | 22 (26.2) | 219 (15.1) | 75 (13.0) | 45 (18.4) | 25 (29.8) |
Normal weight (18.5–24.9) | 1118 (73.9) | 427 (73.6) | 179 (68.6) | 49 (58.3) | 1097 (75.4) | 436 (75.8) | 167 (68.4) | 43 (51.2) |
Overweight (≥ 25) | 143 (9.5) | 65 (11.2) | 49 (18.8) | 13 (15.5) | 137 (9.4) | 64 (11.1) | 32 (13.1) | 16 (19.0) |
Missing | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 1 (0.1) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
Maternal age at parturition (y) | ||||||||
< 20 | 4 (0.3) | 1 (0.2) | 2 (0.8) | 0 (0.0) | 2 (0.1) | 1 (0.2) | 3 (1.2) | 1 (1.2) |
20–24 | 78 (5.2) | 25 (4.3) | 31 (11.9) | 15 (17.9) | 75 (5.2) | 30 (5.2) | 44 (18.0) | 12 (14.3) |
25–29 | 357 (23.6) | 116 (20.0) | 91 (34.9) | 30 (35.7) | 357 (24.6) | 134 (23.3) | 76 (31.1) | 26 (31.0) |
30–34 | 582 (38.5) | 212 (36.6) | 83 (31.8) | 19 (22.6) | 565 (38.9) | 195 (33.9) | 61 (25.0) | 19 (22.6) |
35–40 | 400 (26.5) | 180 (31.0) | 49 (18.8) | 15 (17.9) | 369 (25.4) | 168 (29.2) | 47 (19.3) | 21 (25.0) |
≥ 40 | 91 (6.0) | 46 (7.9) | 5 (1.9) | 5 (6.0) | 86 (5.9) | 47 (8.2) | 13 (5.3) | 5 (6.0) |
Annual household income (million JPN) | ||||||||
< 4 | 441 (29.2) | 223 (38.4) | 126 (48.3) | 47 (56.0) | 432 (29.7) | 238 (41.4) | 124 (50.8) | 50 (59.5) |
4–7.9 | 789 (52.2) | 276 (47.6) | 111 (42.5) | 28 (33.3) | 761 (52.3) | 271 (47.1) | 92 (37.7) | 24 (28.6) |
≥ 8 | 224 (14.8) | 57 (9.8) | 13 (5.0) | 2 (2.4) | 196 (13.5) | 48 (8.3) | 11 (4.5) | 3 (3.6) |
Missing | 58 (3.8) | 24 (4.1) | 11 (4.2) | 7 (8.3) | 65 (4.5) | 18 (3.1) | 17 (7.0) | 7 (8.3) |
Parity | ||||||||
One | 639 (42.3) | 186 (32.1) | 140 (53.6) | 33 (39.3) | 612 (42.1) | 186 (32.3) | 126 (51.6) | 27 (32.1) |
2 or more | 866 (57.3) | 386 (66.6) | 121 (46.4) | 49 (58.3) | 833 (57.3) | 385 (67.0) | 115 (47.1) | 57 (67.9) |
Missing | 7 (0.5) | 8 (1.4) | 0 (0.0) | 2 (2.4) | 9 (0.6) | 4 (0.7) | 3 (1.2) | 0 (0.0) |
Birth weight (g) | 3088 ± 414.7 | 3119 ± 416.7 | 3105 ± 416.3 | 3071 ± 309.7 | 3007 ± 379.0 | 3012 ± 385.3 | 3034 ± 421.9 | 2854 ± 434.6 |
Maternal blood Cadmium concentration (ng/g) | 0.711 ± 0.343 | 0.733 ± 0.335 | 0.845 ± 0.425 | 1.150 ± 0.517 | 0.718 ± 0.352 | 0.728 ± 0.342 | 0.767 ± 0.370 | 1.146 ± 0.464 |
- BMI body mass index, SD standard deviation.