Table 1. Distribution of Socio-Demographic, Perinatal, and Child Factors by Study Group, Study to Explore Early Development (SEED), United States.
| ASD (N=356) | DD (N=627) | POP (N=524) | P ASD vs POP | P DD vs POP | |
|---|---|---|---|---|---|
| % | % | % | |||
| Child sex | |||||
| Male | 81.7 | 64.9 | 53.6 | <0.001 | <0.001 |
| Female | 18.3 | 35.1 | 46.4 | ||
| Maternal race/ethnicity | |||||
| Non-Hispanic-white | 51.7 | 58.5 | 71.4 | <0.001 | <0.001 |
| Non-Hispanic-black | 23.9 | 17.7 | 13.2 | ||
| Hispanic | 13.5 | 14.8 | 8.2 | ||
| Non-Hispanic –Asian/Pacific Islander/American Indian | 7.6 | 4.2 | 4.0 | ||
| Non-Hispanic -multiracial | 3.4 | 4.8 | 3.2 | ||
| Maternal age at birth (years) | |||||
| <25 | 9.8 | 8.1 | 7.1 | 0.270 | 0.728 |
| 25–34 | 56.7 | 56.8 | 56.3 | ||
| ≥35 | 33.4 | 35.1 | 36.7 | ||
| Maternal education at birth (years) | |||||
| <12 | 25.3 | 25.8 | 13.7 | <0.001 | <0.001 |
| 13–15 | 30.9 | 23.6 | 27.9 | ||
| ≥16 | 43.8 | 50.6 | 58.4 | ||
| Gestational age at birth (weeks) | |||||
| <37 | 14.3 | 21.9 | 8.2 | 0.004 | <0.001 |
| ≥37 | 85.7 | 78.2 | 91.8 | ||
| Mother trying to get pregnant just before index pregnancy | |||||
| Yes | 52.3 | 59.0 | 62.4 | 0.004 | 0.249 |
| No | 47.7 | 41.1 | 37.6 | ||
| Maternal diagnosis of infertility disorder prior to index pregnancy | |||||
| Yes | 18.9 | 16.3 | 12.3 | 0.010 | 0.068 |
| No | 81.1 | 83.7 | 87.7 | ||
| Maternal hypertension during index pregnancy | |||||
| Yes | 13.8 | 14.6 | 9.1 | 0.030 | 0.006 |
| No | 86.2 | 85.4 | 90.9 | ||
| Maternal diabetes during index pregnancy | |||||
| Yes | 9.0 | 12.1 | 8.1 | 0.640 | 0.032 |
| No | 91.0 | 87.9 | 91.9 | ||
| Intellectual disability | |||||
| Yes | 66.8 | 24.0 | 2.8 | <0.001 | <0.001 |
| No | 33.2 | 76.0 | 97.2 | ||
| ASD severity | |||||
| More severe (ADOS score 8–10) | 41.1 | NA | NA | NA | NA |
| Less severe (ADOS score 4–7) | 58.9 | ||||
| DD group with autism symptoms? | |||||
| Yes | NA | 27.3 | NA | NA | NA |
| No | 72.7 | ||||
ASD is autism spectrum disorder case group; DD is other (non-ASD) developmental delay; POP is general population control group: ADOS is Autism Diagnostic Interview Schedule.