Table 1.
Characteristics of cases and controls, study to explore early development
| ASD (N = 599) % | POP (N = 811) % | |
|---|---|---|
| Child sex | ||
| Male | 81.30 | 53.14 |
| Female | 18.70 | 46.86 |
| Child race/ethnicity | ||
| Non-Hispanic White | 54.75 | 68.38 |
| Non-Hispanic Black | 17.80 | 10.92 |
| Hispanic | 13.39 | 11.17 |
| Asian | 5.93 | 3.26 |
| Mixed | 8.14 | 6.27 |
| Age at hand scan (months) | ||
| < 48 | 5.56 | 7.60 |
| 48–59 | 37.54 | 32.88 |
| 60+ | 56.90 | 59.53 |
| Maternal age at birth (years) | ||
| ≤ 34 | 71.81 | 68.60 |
| 35+ | 28.19 | 31.40 |
| Maternal education at birth (years) | ||
| ≤ 15 | 48.41 | 33.83 |
| 16+ | 51.59 | 66.17 |
| Birth order | ||
| First birth | 48.71 | 45.56 |
| Second birth or later | 51.29 | 54.44 |
| Gestational age | ||
| Term | 83.22 | 90.84 |
| Preterm (< 37 weeks) | 16.78 | 9.16 |
| Birth plurality | ||
| Singleton | 91.08 | 96.24 |
| Multiple birth | 8.92 | 3.76 |
| Any maternal infertility disorder diagnosed prior to index pregnancy | ||
| Yes | 20.45 | 14.95 |
| No | 79.55 | 85.05 |
| Any maternal use ovulation medications to help get pregnant | ||
| Yes | 9.94 | 9.28 |
| No | 90.06 | 90.72 |
| Any maternal use progesterone medications to help get pregnant or maintain pregnancy | ||
| Yes | 10.69 | 9.54 |
| No | 89.31 | 90.46 |
| Maternal pre-pregnancy BMI (kg/m2) | ||
| < 25 | 56.33 | 64.40 |
| 25.0–29.9 | 25.67 | 21.85 |
| ≥ 30 | 18.00 | 13.75 |
| Maternal prenatal smoking | ||
| No | 90.97 | 95.97 |
| Yes | 9.03 | 4.03 |
ASD Autism spectrum disorder case group, POP population control group, BMI body mass index
Data excluded due to missing values for individual factors. Missing values were 0% for child sex, 1–5% for maternal age, maternal education, birth order, gestational age and birth plurality, and maternal pre-pregnancy BMI, and 6–9% for maternal infertility conditions, ovulation induction medications, progesterone medications, and smoking