Table 1 Descriptive information on the first four children born in analyzed families, on individual-, family-, and inter-pregnancy interval levels
From: Reproductive stoppage in autism spectrum disorder in a population of 2.5 million individuals
Individual level descriptive information | Children with ASD diagnosis | Children without ASD diagnosis | |
Number of individuals (% of total) | 26,842 (1.1) | 2,476,592 (98.9) | |
Number of individuals (column %) | Number of individuals (column %) | ||
Sex | Male | 19,081 (71.1) | 1,268,115 (51.2) |
Female | 7761 (28.9) | 1,208,477 (48.8) | |
Birth order | 1 | 15,383 (57.3) | 1,254,634 (50.7) |
2 | 8414 (31.3) | 889,411 (35.9) | |
3 | 2472 (9.2) | 270,100 (10.9) | |
4 | 573 (2.1) | 62,447 (2.5) | |
Maternal age | < 20 | 1084 (4.0) | 74,574 (3.0) |
20–24 | 6173 (23.0) | 476,466 (19.2) | |
25–29 | 9292 (34.6) | 852,599 (34.4) | |
30–34 | 6912 (25.8) | 730,188 (29.5) | |
35–39 | 2868 (10.7) | 292,915 (11.8) | |
40–44 | 494 (1.8) | 47,978 (1.9) | |
≥ 45 | 19 (0.1) | 1872 (0.1) | |
Paternal age | < 20 | 872 (3.2) | 103,102 (4.2) |
20–24 | 3103 (11.6) | 219,819 (8.9) | |
25–29 | 7487 (27.9) | 659,913 (26.6) | |
30–34 | 7933 (29.6) | 788,390 (31.8) | |
35–39 | 4518 (16.8) | 456,482 (18.4) | |
40–44 | 1841 (6.9) | 169,901 (6.9) | |
45–49 | 731 (2.7) | 54,048 (2.2) | |
≥ 50 | 357 (1.3) | 24,937 (1.0) | |
Family level descriptive information | Families with children with ASD diagnosisa | Families without children with ASD diagnosisa | |
Number of families (% of total) | 25,489 (2.0) | 1,244,528 (98.0) | |
Childbearing rate | Total number of children (% of total)b | 61,842 (2.4) | 2,480,416 (97.6) |
Mean family size | 2.4 | 2.0 | |
Total years of follow-up | 451,368.4 | 16,145,609.0 | |
Average years of follow-up per mother | 17.6 | 13.0 | |
Rate (children/1000 years) | 137.7 | 153.6 | |
Number of families (column %) | Number of families (column %) | ||
Family size | 1 | 3813 (15.0) | 368,379 (29.6) |
2 | 11,873 (46.6) | 613,380 (49.3) | |
3 | 6714 (26.3) | 202,838 (16.3) | |
4 | 2118 (8.3) | 43,233 (3.5) | |
≥ 5 | 971 (3.8) | 16,698 (1.3) | |
Highest maternal education level | Information not available | 171 (0.7) | 36,829 (3.0) |
Primary and lower secondary education less than 9 years | 469 (1.8) | 31,339 (2.5) | |
Primary and lower secondary education 9 years | 2386 (9.4) | 81,628 (6.6) | |
Upper secondary education 1–2 years | 6581 (25.8) | 221,040 (17.8) | |
Upper secondary education 3 years | 5466 (21.4) | 296,444 (23.8) | |
Post-secondary education less than 3 years | 3867 (15.2) | 182,915 (14.7) | |
Post-secondary education 3 years or longer | 6304 (24.7) | 379,577 (30.5) | |
Postgraduate education | 245 (1.0) | 14,756 (1.2) | |
Inter-pregnancy intervals Initial birth before January 1, 2012 | Inter-pregnancy intervals with an immediately prior born child with ASD diagnosis | Inter-pregnancy intervals with an immediately prior born child without ASD diagnosis | |
Number of inter-pregnancy intervals (% of total) | 26,831 (1.2) | 2,269,306 (98.8) | |
Inter-pregnancy intervals that ended with a birth (% within each group) | 16,156 (60.2) | 1,230,071 (54.2) | |
Number of inter-pregnancy intervals (% per birth interval and group) | Number of inter-pregnancy intervals (% per birth interval and group) | ||
Inter-pregnancy intervals | Observed 1st to 2nd | 11,636 (75.7) | 882,951 (76.1) |
Censored 1st to 2nd | 3742 (24.3) | 277,066 (23.9) | |
Observed 2nd to 3rd | 3451 (41.0) | 268,023 (33.1) | |
Censored 2nd to 3rd | 4962 (59.0) | 542,798 (66.9) | |
Observed 3rd to 4th | 844 (34.2) | 61,803 (25.4) | |
Censored 3rd to 4th | 1623 (65.8) | 181,271 (74.6) | |
Observed 4th to 5th | 225 (39.3) | 17,294 (31.2) | |
Censored 4th to 5th | 348 (60.7) | 38,100 (68.8) | |
Mean time (standard deviation) | Mean time (standard deviation) | ||
Observed 1st to 2nd | 3.5 (2.5) | 3.3 (2.1) | |
Censored 1st to 2nd | 15.3 (6.7) | 10.9 (7.8) | |
Observed 2nd to 3rd | 4.4 (2.9) | 4.3 (2.8) | |
Censored 2nd to 3rd | 15.1 (5.6) | 11.9 (6.7) | |
Observed 3rd to 4th | 4.2 (3.0) | 3.9 (2.7) | |
Censored 3rd to 4th | 13.8 (5.0) | 10.7 (5.9) | |
Observed 4th to 5th | 3.5 (2.4) | 3.5 (2.4) | |
Censored 4th to 5th | 12.3 (4.5) | 9.2 (5.1) | |