Baseline characteristics of the study population
| Characteristic | Paternal SSRI use during the last 3 months prior to conception (n=6870) | No paternal SSRI use during the last 3 months prior to conception (n=663 052) |
| Calendar year of birth, n (%) | ||
| 1998–2000 | 1021 (14.9) | 185 784 (28.0) |
| 2001–2003 | 1526 (22.2) | 179 952 (27.1) |
| 2004–2006 | 2305 (33.5) | 178 664 (27.0) |
| 2007–2008 | 2018 (29.4) | 118 652 (17.9) |
| Gender, n (%) | ||
| Boy | 3549 (51.7) | 340 194 (51.3) |
| Girl | 3321 (48.3) | 322 858 (48.7) |
| Birth weight (g), n (%) | ||
| <2500 | 278 (4.1) | 22 315 (3.4) |
| 2500–3250 | 1729 (25.2) | 154 494 (23.3) |
| 3250–4000 | 3582 (52.1) | 348 853 (52.6) |
| 4000–8000 | 1243 (18.1) | 132 343 (19.9) |
| Unknown | 38 (0.5) | 5047 (0.8) |
| Parity, n (%) | ||
| 1 | 2693 (39.2) | 282 895 (42.7) |
| 2 | 2433 (35.4) | 250 496 (37.8) |
| ≥3 | 1744 (25.4) | 129 661 (19.5) |
| Preterm birth, n (%) (<37 weeks) | ||
| No | 6489 (94.4) | 630 851 (95.1) |
| Yes | 381 (5.6) | 32 201 (4.9) |
| Apgar score at 5 min, n (%) | ||
| 0–7 | 91 (1.3) | 8224 (1.2) |
| 8–9 | 442 (6.4) | 39 941 (6.0) |
| 10 | 6269 (91.3) | 607 634 (91.7) |
| Unknown | 68 (1.0) | 7253 (1.1) |
| Maternal age at child birth (years), n (%) | ||
| ≤25 | 958 (13.9) | 99 273 (15.0) |
| 26–30 | 2238 (32.6) | 244 419 (36.9) |
| 31–35 | 2386 (34.7) | 225 610 (34.0) |
| >35 | 1288 (18.8) | 93 750 (14.1) |
| Paternal age at child birth (years), n (%) | ||
| ≤25 | 364 (5.3) | 47 490 (7.2) |
| 26–30 | 1434 (20.9) | 180 612 (27.2) |
| 31–35 | 2395 (34.8) | 242 702 (36.6) |
| >35 | 2677 (39.0) | 192 248 (29.0) |
| Maternal smoking status*, n (%) | ||
| No | 4326 (63.0) | 477 574 (72.0) |
| Yes | 1334 (19.4) | 106 233 (16.0) |
| Unknown | 1210 (17.6) | 79 245 (12.0) |
| Maternal AD use during pregnancy, n (%) | ||
| No | 6548 (94.0) | 653 496 (98.6) |
| Yes | 412 (6.0) | 9556 (1.4) |
| Maternal history of affective disorder, n (%) | ||
| No | 6607 (96.2) | 654 234 (98.7) |
| Yes | 263 (3.8) | 8818 (1.3) |
| Paternal history of affective disorder, n (%) | ||
| No | 6099 (88.8) | 659 639 (99.5) |
| Yes | 771 (11.2) | 3413 (0.5) |
| Maternal history of psychiatric disorder, n (%) | ||
| No | 6175 (89.9) | 626 840 (94.5) |
| Yes | 695 (10.1) | 36 212 (5.5) |
| Paternal history of psychiatric disorder, n (%) | ||
| No | 5092 (74.1) | 630 990 (95.2) |
| Yes | 1178 (25.9) | 32 062 (4.8) |
*Maternal smoking information was missing among those children born from 2007 to 2008.
AD, antidepressant drug; n, number; SSRI, selective serotonin reuptake inhibitor.