Table 3:
Individual and joint association of preterm birth and histological chorioamnionitis (CA) with child’s risk of ASD, ADHD, and other DD*, using a common reference group of neurotypical children
| Total n | ASD n | Unadjusted | Adjusted | Total n | ADHD n | Unadjusted | Adjusted | Total n | DD n | Unadjusted | Adjusted** | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Individual associations | ||||||||||||
| Term | 241 | 30 | 1.0 (Ref) | 316 | 105 | 1.0 (Ref) | 376 | 165 | 1.0 (Ref) | |||
| Preterm | 199 | 47 | 2.17 (1.31, 3.60) | 2.06 (1.22, 3.49) | 262 | 110 | 1.45 (1.04, 2.04) | 1.34 (0.93, 1.92) | 363 | 211 | 1.78 (1.33, 2.38) | 1.68 (1.25, 2.27) |
| Spontaneous | 118 | 29 | 2.29 (1.30, 4.04) | 2.10 (1.15, 3.85) | 158 | 69 | 1.56 (1.05, 2.31) | 1.48 (0.97, 2.26) | 218 | 129 | 1.85 (1.32, 2.60) | 1.75 (1.24, 2.48) |
| Medically Indicated | 81 | 18 | 2.01 (1.05, 3.84) | 1.89 (0.96, 3.70) | 104 | 41 | 1.31 (0.83, 2.07) | 1.15 (0.70, 1.91) | 145 | 82 | 1.66 (1.13, 2.45) | 1.57 (1.05, 2.33) |
| No CA | 340 | 60 | 1.0 (Ref) | 428 | 148 | 1.0 (Ref) | 559 | 279 | 1.0 (Ref) | |||
| CA | 100 | 17 | 0.96 (0.53, 1.73) | 1.03 (0.56, 1.92) | 150 | 67 | 1.53 (1.05, 2.23) | 1.74 (1.15, 2.62) | 180 | 97 | 1.17 (0.84, 1.64) | 1.17 (0.83, 1.65) |
| Combined association of preterm with CA | ||||||||||||
| Term, no CA | 185 | 24 | 1.0 (Ref) | 239 | 78 | 1.0 (Ref) | 281 | 120 | 1.0 (Ref) | |||
| Term, CA | 56 | 6 | 0.81 (0.31, 2.08) | 0.86 (0.32, 2.29) | 77 | 27 | 1.11 (0.65, 1.91) | 1.14 (0.64, 2.03) | 95 | 45 | 1.21 (0.76, 1.93) | 1.25 (0.77, 2.01) |
| Preterm, no CA | 155 | 36 | 2.03 (1.15, 3.58) | 1.92 (1.06, 3.46) | 189 | 70 | 1.21 (0.81, 1.81) | 1.04 (0.68, 1.60) | 278 | 159 | 1.79 (1.28, 2.51) | 1.73 (1.23, 2.43) |
| Preterm, CA | 44 | 11 | 2.24 (1.00, 5.01) | 2.31 (0.99, 5.39) | 73 | 40 | 2.50 (1.47, 4.27) | 2.75 (1.55, 4.90) | 85 | 52 | 2.11 (1.29, 3.47) | 1.96 (1.18, 3.25) |
| Combined association of spontaneous preterm with CA | ||||||||||||
| Term, no CA | 185 | 24 | 1.0 (Ref) | 239 | 78 | 1.0 (Ref) | 281 | 120 | 1.0 (Ref) | |||
| Term, CA | 56 | 6 | 0.81 (0.31, 2.08) | 0.85 (0.32, 2.26) | 77 | 27 | 1.11 (0.65, 1.91) | 1.11 (0.62, 1.98) | 95 | 45 | 1.21 (0.76, 1.93) | 1.20 (0.74, 1.94) |
| Spon. preterm, no CA | 81 | 19 | 2.06 (1.05, 4.01) | 1.82 (0.89, 3.70) | 99 | 37 | 1.23 (0.76, 2.01) | 1.04 (0.62, 1.77) | 143 | 81 | 1.75 (1.17, 2.63) | 1.64 (1.08, 2.49) |
| Spon. preterm, CA | 37 | 10 | 2.48 (1.07, 5.78) | 2.59 (1.04, 6.46) | 59 | 32 | 2.45 (1.37, 4.37) | 2.80 (1.49, 5.24) | 75 | 48 | 2.39 (1.41, 4.04) | 2.29 (1.33, 3.92) |
| Combined association of medically indicated preterm with CA | ||||||||||||
| Term, no CA | 185 | 24 | 1.0 (Ref) | 239 | 78 | 1.0 (Ref) | 281 | 120 | 1.0 (Ref) | |||
| Term, CA | 56 | 6 | 0.81 (0.31, 2.08) | 0.86 (0.33, 2.29) | 77 | 27 | 1.11 (0.65, 1.91) | 1.13 (0.63, 2.04) | 95 | 45 | 1.21 (0.76, 1.93) | 1.27 (0.78, 2.05) |
| Med. Preterm, no CA | 74 | 17 | 2.00 (1.00, 3.99) | 1.90 (0.93, 3.89) | 90 | 33 | 1.20 (0.72, 1.98) | 1.03 (0.59, 1.79) | 135 | 78 | 1.84 (1.21, 2.78) | 1.76 (1.15, 2.70) |
| Med. Preterm, CA | 7 | 1 | 1.12 (0.13, 9.69) | 1.08 (0.11, 10.21) | 14 | 8 | 2.75 (0.92, 8.21) | 2.93 (0.88, 9.74) | 10 | 4 | 0.89 (0.25, 3.24) | 0.75 (0.19, 2.88) |
*
ASD – Autism Spectrum Disorder; ADHD – Attention-Deficit/Hyperactivity Disorder; DD – Developmental disabilities; Med. Preterm – Medically indicated preterm; Spon. Preterm – Spontaneous preterm
**
Adjusted for maternal smoking, age, education, parity, race and child’s sex
Test of interactions were performed for all the above analyses, but none reached statistical significance (p<0.05)