Autism Spectrum Disorder and Particulate Matter Air Pollution before, during, and after Pregnancy: A Nested Case–Control Analysis within the Nurses’ Health Study II Cohort

http://dx.doi.org/10.1289/ehp.1408133



Table 1. Study population characteristics by ASD status, Nurses’ Health Study II.
Characteristic Cases (= 245) Controls (= 1,522)
IQR, Interquartile range.
Male sex [n (%)] 209 (85) 793 (52)
Year of birth [median (IQR)] 1993 (5) 1993 (5)
Maternal age at birth (years) (mean ± SD) 34.0 ± 4.0 33.7 ± 3.7
Paternal age at birth (years) (mean ± SD) 36.8 ± 5.3 36.3 ± 4.9
Median census income ($1,000) [median (IQR)] 63 (26) 61 (27)
Median census house value ($1,000) [median (IQR)] 144 (108) 136 (98)
Birth weight (lbs) (mean ± SD) 7.1 ± 1.5 7.2 ± 1.3
Husband’s/partner’s education [n (%)]    
High school 33 (13) 208 (14)
2-year college 45 (18) 218 (14)
4-year college 79 (32) 537 (35)
Graduate school 74 (30) 501 (33)
Missing 14 (6) 58 (4)
Marital status [n (%)]    
Married 186 (76) 1,159 (76)
Never married 51 (21) 269 (18)
Other 8 (3) 94 (6)
Premature birth [n (%)]    
Yes 44 (18) 227 (15)
No 142 (58) 1,137 (75)
Missing 59 (24) 158 (10)
Gestational diabetes [n (%)]    
Yes 17 (7) 87 (6)
No 189 (77) 1,222 (80)
Missing 39 (16) 213 (14)
Preeclampsia [n (%)]    
Yes 13 (5) 43 (3)
No 193 (79) 1,266 (83)
Missing 39 (16) 213 (14)
Smoking during pregnancy [n (%)]    
Yes 22 (9) 50 (3)
No 160 (65) 1,099 (72)
Missing 63 (26) 373 (25)