Table 1.
Raw percentages, means (standard deviations) by cytokine, and percentage PTB for each demographic characteristic
| Percent (n = 470) | Mean levels (s.d.) of IL-1Ra (pg ml−1) | Mean levels (s.d.) of IL-6 (pg ml−1) | Mean levels (s.d.) of IL-10 (pg ml−1) | Preterm birth % (n = 33) | |
|---|---|---|---|---|---|
| Age (in years) | |||||
| Younger than 18 | 6.0% | 400.06 (373.41) | 1.03 (0.91) | 2.47 (3.37) | 7.1% |
| 18 to 34 | 91.3% | 302.57 (314.48) | 1.74 (1.73) | 2.90 (5.58) | 7.2% |
| 35 or older | 2.8% | 392.30 (239.53) | 1.35 (0.73) | 1.82 (2.18) | 0.0 |
| Body mass index | |||||
| Normal | 49.4% | 266.96 (250.68) | 1.52 (1.71) | 3.47 (6.95) | 8.3% |
| Overweight | 33.2% | 330.65 (354.50) | 1.77 (1.65) | 2.43 (3.55) | 6.6% |
| Obese | 17.4% | 325.95 (209.24) | 1.71 (1.12) | 2.20 (2.88) | 2.8% |
| Gravida | |||||
| 1 Pregnancy | 27.6% | 273.79 (234.53) | 1.68 (1.92) | 2.21 (2.75)* | 8.6% |
| 2 Pregnancies | 30.2% | 309.34 (323.53) | 1.73 (1.83) | 2.60 (4.07) | 3.6% |
| 3 Pregnancies | 22.9% | 330.33 (408.49) | 1.74 (1.62) | 4.29 (9.46)* | 9.4% |
| 4 or More pregnancies | 19.2% | 353.61 (308.17) | 1.57 (1.10) | 2.40 (2.91) | 7.9% |
| Marital status | |||||
| Not married | 57.4% | 346.35** (378.68) | 1.74 (1.83) | 2.81 (4.85) | 6.7% |
| Currently married | 42.6% | 263.41 (198.81) | 1.61 (1.46) | 2.88 (6.10) | 7.5% |
| History of preterm birth | |||||
| No | 92.1% | 303.02 (289.05) | 1.70 (1.72) | 2.94 (5.59) | 6.2%* |
| Yes | 7.9% | 412.46 (556.19) | 1.60 (1.15) | 1.60 (1.78) | 16.2% |
| Infection during pregnancy | |||||
| No | 56.0% | 303.64 (324.13) | 1.78 (1.73) | 3.02 (6.09) | 8.1% |
| Yes | 44.0% | 324.39 (327.08) | 1.64 (1.71) | 2.49 (4.51) | 5.2% |
Abbreviations: IL-1Ra, interleukin-1 receptor antagonist; PTB, preterm birth.
*
P<0.05.
**
P<0.005.