Table 1 Baseline characteristics of the study population
Denmark | Sweden | |||||
|---|---|---|---|---|---|---|
Characteristics | Exposed | Unexposed | P value | Exposed | Unexposed | P value |
(N = 29,475) | (N = 2,097,651) | (N = 56,542) | (N = 2,918,366) | |||
N (%) | N (%) | N (%) | N (%) | |||
Sex | ||||||
Boy | 14,981(51) | 1,076,217(51) | 29,006(51) | 1,499,551(51) | ||
Girl | 14,494(49) | 1,021,434(49) | 0.10 | 27,536(49) | 1,418,815(49) | 0.69 |
Maternal age (years) | ||||||
15–26 | 7,924(27) | 708,240(34) | 15,422(27) | 1,073,318(37) | ||
27–30 | 8,613(29) | 640,409(31) | 15,617(28) | 849,158(29) | ||
31–59 | 12,938(44) | 749,002(36) | <0.01 | 25,503(45) | 995,890(34) | <0.01 |
Paternal age (years) | ||||||
15–28 | 7,393(25) | 622,992(30) | 15,161(27) | 976,972(33) | ||
29–33 | 10,191(35) | 726,459(35) | 18,847(33) | 986,054(34) | ||
≥ 34 | 11,137(38) | 681,103(32) | 22,201(39) | 935,866(32) | ||
Unknown | 754(3) | 67,097(3) | <0.01 | 333(1) | 19,474(1) | <0.01 |
Parity | ||||||
1 | 11,035(37) | 979,756(47) | 18,131(32) | 1,223,966(42) | ||
2 | 11,723(40) | 778,384(37) | 21,144(37) | 1,056,861(36) | ||
≥ 3 | 6,711(23) | 333,485(16) | 17,265(31) | 637,471(22) | ||
Unknown | 6(0) | 6,026(0) | <0.01 | 2(0) | 68(0) | <0.01 |
Number of fetuses in the pregnancy | ||||||
Singleton | 28,099(95) | 1,898,839(91) | 55,091(97) | 2,846,323(98) | ||
Multiple | 953(3) | 64,731(3) | 1,446(3) | 71,866(2) | ||
Unknown | 423(1) | 134,081(6) | <0.01 | 5(0) | 177(0) | 0.25 |
Maternal countries of origin | ||||||
Nordic | 29,275(99) | 2,074,856(99) | 54,543(96) | 2,603,304(89) | ||
Others | 194(1) | 13,129(1) | 1,963(3) | 302,486(10) | ||
Unknown | 6(0) | 9,666(0) | <0.01 | 36(0) | 12,576(0) | <0.01 |
Family history of psychiatric disorders | ||||||
No | 26,173(89) | 1,912,542(91) | 51,896(92) | 2,717,203(93) | ||
Yes | 3,302(11) | 185,109(9) | <0.01 | 4,646(8) | 201,163(7) | <0.01 |
Maternal education | ||||||
≤ 9 years | 8,662(29) | 546,022(26) | 10,196(18) | 487,899(17) | ||
10–14 years | 12,601(43) | 825,834(39) | 36,664(65) | 1,823,765(62) | ||
≥ 15 years | 6,821(23) | 438,799(21) | 8,620(15) | 403,798(14) | ||
Unknown | 1,391(5) | 286,996(14) | <0.01 | 1,062(2) | 202,904(7) | <0.01 |