TABLE 4.
Autism risk by gestational age and birthweight percentile
| Gestational age groups | All (23–43 wks) | 23–31 wks | 32–33 wks | 34–36 wks | 37–38 wks | 39–41 wks | ≥42 wks | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | aOR | 95% CI | |
|
| ||||||||||||||
| Birthweight percentile | ||||||||||||||
|
| ||||||||||||||
| SGA: <5% | 1.10 | 1.04–1.18 | 1.60 | 1.09–2.35 | 1.83 | 1.16–2.87 | 1.07 | 0.86–1.34 | 1.10 | 0.97–1.25 | 1.09 | 1.00–1.18 | 1.24 | 0.98–1.58 |
|
| ||||||||||||||
| SGA: 5–10% | 1.04 | 0.98–1.11 | 1.36 | 0.91–2.02 | 1.00 | 0.57–1.78 | 1.12 | 0.91–1.38 | 1.01 | 0.89–1.15 | 1.03 | 0.95–1.12 | 1.17 | 0.92–1.48 |
|
| ||||||||||||||
| AGA: >10 to <90% | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference | 1.00 | Reference |
|
| ||||||||||||||
| LGA: 90–95% | 1.04 | 0.97–1.10 | 0.49 | 0.25–0.95 | 0.56 | 0.25–1.26 | 1.04 | 0.84–1.30 | 0.98 | 0.86–1.11 | 1.07 | 0.99–1.16 | 1.16 | 0.92–1.46 |
|
| ||||||||||||||
| LGA: >95% | 1.12 | 1.05–1.18 | 0.45 | 0.21–0.95 | 1.00 | 0.52–1.89 | 0.97 | 0.77–1.22 | 1.10 | 0.97–1.24 | 1.16 | 1.08–1.26 | 1.11 | 0.88–1.41 |
The odds ratios were adjusted for maternal age, race, hypertension, preeclampsia, diabetes, birth order, twin gestation, and months since last live birth. The analysis included infants that survived to 1 year of age. 95% confidence internals (CIs) and adjusted odds ratios (aOR) are reported.
AGA, appropriate-for-gestational age; LGA, large-for-gestational age; SGA, small-for-gestational age.
Moore. Autism risk by birthweight percentile. Am J Obstet Gynecol 2012.