Table 3.
Infant and maternal characteristics among singleton Juvenile Idiopathic Arthritis (JIA) case categories and controls born in WA State, 1997–2010
| Persistent Oligoarthritis | Extended Oligoarthritis | RF+ Polyarthritis | RF- Polyarthritis | Systemic JIA | Enthesitis Related Arthritis | Psoriatic Arthritis | Undifferentiated JIA | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N a (%) | 389 | 31.50% | 73 | 5.90% | 60 | 4.90% | 256 | 20.70% | 71 | 5.80% | 262 | 21.20% | 62 | 5.00% | 39 | 3.20% |
| ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | ORb | 95% CI | |
| Infant factors | ||||||||||||||||
| Gest. age (wks) | ||||||||||||||||
| < 37 | 0.71 | 0.43, 1.18 | - | - | 2.23 | 1.04, 4.80 | 0.64 | 0.33,1.21 | 1.67 | 0.76, 3.69 | 1.9 | 1.27, 2.86 | - | - | - | - |
| 37–42 | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| 42+ | 0.88 | 0.60, 1.29 | 1.31 | 0.62, 2.75 | 0.74 | 0.29, 1.89 | 0.83 | 0.52, 1.33 | 1.07 | 0.48, 2.35 | 0.81 | 0.51, 1.29 | 0.79 | 0.31, 2.00 | - | - |
| Size for gest age | ||||||||||||||||
| SGA | 0.95 | 0.64, 1.40 | 0.79 | 0.31, 1.99 | - | - | 0.97 | 0.60, 1.55 | 1.03 | 0.44, 2.41 | 1.03 | 0.65, 1.62 | 1.31 | 0.55, 3.13 | 2.64 | 1.18, 5.94 |
| AGA | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| LGA | 1.16 | 0.82, 1.63 | 0.99 | 0.45, 2.18 | 1.42 | 0.60, 3.40 | 1.07 | 0.69, 1.65 | 0.8 | 0.32, 2.01 | 0.93 | 0.59, 1.47 | - | - | - | - |
| Birth weight (g) | ||||||||||||||||
| < 2500 | 0.84 | 0.51, 1.40 | 0.24 | 0.03, 1.77 | 2.29 | 1.03, 5.13 | 1.1 | 0.63, 1.92 | 1.88 | 0.85, 4.15 | 1.18 | 0.69, 2.02 | - | - | - | - |
| 2500–3999 | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| ≥ 4000 | 0.85 | 0.62, 1.17 | 0.55 | 0.24, 1.28 | 0.66 | 0.26, 1.67 | 0.89 | 0.61, 1.31 | - | - | 0.96 | 0.67, 1.38 | 0.79 | 0.35, 1.74 | - | - |
| Maternal Factors | ||||||||||||||||
| Cesarean Section | ||||||||||||||||
| Yes | 1.17 | 0.92,1.66 | 0.93 | 0.52, 1.66 | 1.8 | 1.00, 3.20 | 1.07 | 0.78, 1.46 | 0.9 | 0.49, 1.65 | 1.14 | 0.84, 1.55 | 1.15 | 0.62, 2.13 | 0.84 | 0.35, 2.01 |
| No | 1 | Reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| No. prior birthc,e | ||||||||||||||||
| 0 | 1 | Reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| 1 | 0.88 | 0.69, 1.12 | 1.02 | 0.60, 1.74 | 0.72 | 0.38, 1.37 | 0.78 | 0.58, 1.06 | 0.92 | 0.53, 1.59 | 1.36 | 1.02, 1.82 | 1.15 | 0.65, 2.04 | 0.66 | 0.31, 1.41 |
| 2 | 0.71 | 0.52, 0.98 | 0.53 | 0.27, 1.04 | 0.67 | 0.27,1.67 | 0.63 | 0.42, 0.95 | 0.94 | 0.47, 1.86 | 0.83 | 0.56, 1.24 | 0.53 | 0.21, 1.33 | 0.6 | 0.25, 1.44 |
| 3 | 0.55 | 0.32, 0.94 | - | - | 1.77 | 0.75, 4.14 | 0.89 | 0.51, 1.53 | 0.64 | 0.24, 1.70 | 0.96 | 0.54, 1.69 | 0.71 | 0.26, 1.94 | - | - |
| 4+ | 0.32 | 0.15, 0.71 | - | - | - | - | 1.24 | 0.70, 2.18 | - | - | 0.65 | 0.31, 1.39 | - | - | - | - |
| Any fetal loss | ||||||||||||||||
| None | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| 1+ | 1.06 | 0.76, 1.47 | 0.77 | 0.35, 1.70 | 2 | 1.00, 4.00 | 2.2 | 1.55, 3.12 | 1.9 | 1.00, 3.64 | 1.59 | 1.16, 2.17 | 2.85 | 1.57, 5.17 | 1.42 | 0.61, 3.30 |
| No. prior fetal losses (<20 w)c | ||||||||||||||||
| None | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| 1+ | 1.11 | 0.80, 1.54 | 0.84 | 0.38, 1.88 | 1.71 | 0.83, 3.51 | 2.08 | 1.46, 2.97 | 1.68 | 0.86, 3.28 | 1.56 | 1.13, 2.14 | 2.62 | 1.44, 4.78 | 1.57 | 0.68, 3.65 |
| No. prior fetal losses ((≥20 w)c, d | ||||||||||||||||
| None | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference | 1 | reference |
| 1+ | - | - | - | - | - | - | 2.25 | 0.96, 5.25 | - | - | 1.9 | 0.86, 4.20 | - | - | - | - |
aEstimates do not include polyarthritis with unknown RF status
bAll estimates are adjusted for maternal age and birth year
cEstimates are restricted to 839 case mothers and 4,015 control mothers with prior pregnancy
dIn addition to maternal age and birth year, also adjusted for paternal age
eP for trends: persistent oligo: ****P0.0001; extended oligo, ***P0.0075. All others are > 0.05
Estimates in italics are statistically significant