Table 1 Characteristics of participants with respect to maternal psychological distress
| Â | Â | Maternal psychological distress | Â | |||
|---|---|---|---|---|---|---|
Total | None | Prenatal only | Postnatal only | Both | Â | |
(n = 6,259) | (n = 3,484) | (n = 1,055) | (n = 701) | (n = 1,019) | P-valuea | |
n (%) | n (%) | n (%) | n (%) | n (%) | Â | |
Maternal age at delivery | ||||||
 < 25 (years) | 291 (4.6) | 134 (3.8) | 56 (5.3) | 31 (4.4) | 70 (6.9) |  < 0.001 |
 25–30 (years) | 1471 (23.5) | 739 (21.2) | 282 (26.7) | 166 (23.7) | 284 (27.9) | |
 30–35 (years) | 2409 (38.5) | 1313 (37.7) | 411 (39.0) | 288 (41.1) | 397 (39.0) | |
  > 35 (years) | 2088 (33.4) | 1298 (37.3) | 306 (29.0) | 216 (30.8) | 268 (26.3) | |
Parity, n (%) | ||||||
 Never | 2949 (47.1) | 1506 (43.2) | 566 (53.6) | 347 (49.5) | 530 (52.0) |  < 0.001 |
 One or more | 3294 (52.6) | 1967 (56.5) | 488 (46.3) | 350 (49.9) | 489 (48.0) | |
 Missing | 16 (0.3) | 11 (0.3) | 1 (0.1) | 4 (0.6) | 0 (0.0) | |
Household income, n (%) | ||||||
  < 4,000,000 (JPY/year) | 1976 (31.6) | 994 (28.5) | 341 (32.3) | 239 (34.1) | 402 (39.5) |  < 0.001 |
 4,000,000–6,000,000 (JPY/year) | 2058 (32.9) | 1154 (33.1) | 373 (35.4) | 210 (30.0) | 321 (31.5) | |
  > 6,000,000 (JPY/year) | 1959 (31.3) | 1196 (34.3) | 303 (28.7) | 221 (31.5) | 239 (23.5) | |
 Missing | 266 (4.2) | 140 (4.0) | 38 (3.6) | 31 (4.4) | 57 (5.6) | |
Educational attainment, n (%) | ||||||
 High school graduate or less | 1736 (27.7) | 930 (26.7) | 272 (25.8) | 204 (29.1) | 330 (32.4) |  |
 Junior college or vocational college graduate | 2288 (36.6) | 1319 (37.9) | 403 (38.2) | 226 (32.2) | 340 (33.4) |  |
 University graduate or above | 1825 (29.2) | 1012 (29.0) | 321 (30.4) | 213 (30.4) | 279 (27.4) | 0.001 |
 Others | 10 (0.2) | 9 (0.3) | 0 (0.0) | 1 (0.1) | 0 (0.0) |  |
 Missing | 400 (6.4) | 214 (6.1) | 59 (5.6) | 57 (8.1) | 70 (6.9) |  |
Maternal Alcohol drinking, n (%) | ||||||
 Never | 2907 (46.4) | 1612 (46.3) | 492 (46.6) | 325 (46.4) | 478 (46.9) | 0.912 |
 Former | 2092 (33.4) | 1158 (33.2) | 347 (32.9) | 235 (33.5) | 352 (34.5) | |
 Current | 1246 (19.9) | 706 (20.3) | 212 (20.1) | 140 (20.0) | 188 (18.4) | |
 Missing | 14 (0.2) | 8 (0.2) | 4 (0.4) | 1 (0.1) | 1 (0.1) | |
Maternal cigarette smoking, n (%) | ||||||
 Never | 4081 (65.2) | 2336 (67.0) | 669 (63.4) | 462 (65.9) | 614 (60.3) | 0.002 |
 Stopped before pregnancy | 1439 (23.0) | 783 (22.5) | 235 (22.3) | 166 (23.7) | 255 (25.0) | |
 Stopped after pregnancy | 633 (10.1) | 316 (9.1) | 128 (12.1) | 63 (9.0) | 126 (12.4) | |
 Current | 88 (1.4) | 41 (1.2) | 19 (1.8) | 7 (1.0) | 21 (2.1) | |
 Missing | 18 (0.3) | 8 (0.2) | 4 (0.4) | 3 (0.4) | 3 (0.3) | |
Paternal cigarette smoking, n (%) | ||||||
 Never | 1944 (31.1) | 1057 (30.3) | 327 (31.0) | 239 (34.1) | 321 (31.5) | 0.212 |
 Stopped before pregnancy | 1518 (24.3) | 863 (24.8) | 264 (25.0) | 170 (24.3) | 221 (21.7) | |
 Stopped after pregnancy | 168 (2.7) | 85 (2.4) | 31 (2.9) | 24 (3.4) | 28 (2.7) | |
 Current | 2583 (41.3) | 1458 (41.8) | 423 (40.1) | 264 (37.7) | 438 (43.0) | |
 Missing | 46 (0.7) | 21 (0.6) | 10 (0.9) | 4 (0.6) | 11 (1.1) | |
Child's sex, n (%) | ||||||
 Male | 3251 (51.9) | 1838 (52.8) | 529 (50.1) | 361 (51.5) | 523 (51.3) | 0.475 |
 Female | 3008 (48.1) | 1646 (47.2) | 526 (49.9) | 340 (48.5) | 496 (48.7) | |
Externalizing problems of CBCL, n (%) | ||||||
 Clinical range | 859 (13.7) | 314 (9.0) | 144 (13.6) | 146 (20.8) | 255 (25.0) |  < 0.001 |
Internalizing problems of CBCL, n (%) | ||||||
 Clinical range | 964 (15.4) | 325 (9.3) | 191 (18.1) | 154 (22.0) | 294 (28.9) |  < 0.001 |
Total problem of CBCL, n (%) | ||||||
 Clinical range | 362 (5.8) | 91 (2.6) | 68 (6.4) | 64 (9.1) | 139 (13.6) |  < 0.001 |
Use child care facilities, n (%) | 2924 (46.7) | 1645 (47.2) | 463 (43.9) | 328 (46.8) | 488 (47.9) |  < 0.001 |