Table 1.
General characteristics of the study population
| Mothers with complete exposure measures (n=9204) | Offspring with all exposure, outcome, and confounding variables (n=3067) | Offspring with missing data (n=6137) | p value* | ||
|---|---|---|---|---|---|
| Maternal antenatal EPDS scores | 6·7 (4·4; 0–29) | 6·1 (4·1; 0–23) | 7·0 (4·5; 0–29) | <0·0001 | |
| Score >12 | 1079 (12%) | 257 (8%) | 822 (13%) | <0·0001 | |
| Maternal postnatal EPDS scores | 5·6 (4·2; 0–27) | 5·2 (3·9; 0–25) | 5·8 (4·3; 0–27) | <0·0001 | |
| Score >12 | 691 (8%) | 170 (6%) | 521 (8%) | <0·0001 | |
| Maternal age at delivery, years | 28·7 (4·64; 15–44) | 29·6 (4·39; 16–44) | 28·3 (4·70; 15–44) | <0·0001 | |
| Maternal parity | 0·81 (0·93; 0–8) | 0·66 (0·81; 0–5) | 0·89 (0·98; 0–8) | <0·0001 | |
| Maternal ethnicity | .. | .. | .. | 0·21 | |
| White | 8963/9132 (98%) | 3015/3064 (98%) | 5948 (98%) | .. | |
| Ethnic minority | 169/9132 (2%) | 49/3064 (2%) | 120 (2%) | .. | |
| Maternal social class | .. | .. | .. | <0·0001 | |
| Non-manual | 6484/7923 (82%) | 2629 (86%) | 3855/4856 (79%) | .. | |
| Manual | 1439/7923 (18%) | 438 (14%) | 1001/4856 (21%) | .. | |
| Maternal education | .. | .. | .. | <0·0001 | |
| Non-compulsory | 3475/9164 (38%) | 1560 (51%) | 1915/3067 (31%) | .. | |
| Compulsory only | 5689/9164 (62%) | 1507 (49%) | 4182/3067 (69%) | .. | |
| Pregnancy intentional or not | .. | .. | .. | <0·0001 | |
| No | 2445/9169 (27%) | 664 (22%) | 1781/6102 (29%) | .. | |
| Yes | 6724/9169 (73%) | 2403 (78%) | 4321/6102 (71%) | .. | |
| Maternal smoking in the first trimester | .. | .. | .. | <0·0001 | |
| No | 7263 (79%) | 2631 (86%) | 4632 (75%) | .. | |
| Yes | 1941 (21%) | 436 (14%) | 1505 (25%) | .. | |
| Maternal cannabis use in the first trimester | .. | .. | .. | 0·091 | |
| No | 8645/8819 (98%) | 3017 (98%) | 5628/5752 (98%) | .. | |
| Yes | 174/8819 (2%) | 50 (2%) | 124/5752 (2%) | .. | |
| Maternal infection during pregnancy | .. | .. | .. | 0·40 | |
| No | 6886/9201 (75%) | 2321 (75%) | 4547/6134 (75%) | .. | |
| Yes | 2315/9201 (25%) | 755 (25%) | 1560/6134 (25%) | .. | |
| Maternal family history of schizophrenia | .. | .. | .. | 0·36 | |
| No | 9014/9071 (99%) | 3051 (99%) | 5963/6004 (99%) | .. | |
| Yes | 57/9014 (1%) | 16 (1%) | 41/6004 (1%) | .. | |
| Maternal family history of depression | .. | .. | .. | 0·010 | |
| No | 6778/9071 (75%) | 2342 (76%) | 4436/6004 (74%) | .. | |
| Yes | 2293/9071 (25%) | 725 (24%) | 1568/6004 (26%) | .. | |
| Maternal history of depression | .. | .. | .. | <0·0001 | |
| No | 8331/9071 (92%) | 2891 (94%) | 5440/6004 (91%) | .. | |
| Yes | 740/9071 (8%) | 176 (6%) | 564/6004 (9%) | .. | |
| Maternal history of schizophrenia | .. | .. | .. | 0·68 | |
| No | 9073/9083 (100%) | 3063 (100%) | 6010/6016 (100%) | .. | |
| Yes | 10/9083 (<1%) | 4 (<1%) | 6/6016 (<1%) | .. | |
| Offspring sex | .. | .. | .. | <0·0001 | |
| Male | 4736 (51·5) | 1361 (44%) | 3375 (55%) | .. | |
| Female | 4468 (48·5) | 1706 (56%) | 2762 (45%) | .. | |
| Offspring depression aged 18 years | .. | .. | .. | 0·048 | |
| No | 3196/3460 (92%) | 2626/2830 (93%) | 570/630 (90·5) | .. | |
| Yes | 264/3460 (8%) | 204/2830 (7%) | 60/630 (9·5) | .. | |
| Offspring psychotic experiences aged 18 years | .. | .. | .. | 0·89 | |
| None | 3322/3586 (93%) | 2842 (93%) | 480/519 (92%) | .. | |
| Suspected or definite | 264/3586 (7%) | 225 (7%) | 39/519 (8%) | .. | |
Data are mean (SD; range), n (%), or n/N (%). EPDS=Edinburgh Postnatal Depression Scale.
*
Comparison between participants with complete data and those with missing data.