Table 3.
Risk of Spontaneous Preterm Birth According to Tertile of Early-Gestation NEFA Level, Pregnancy Exposures and Preeclampsia Prevention Study, 1997–2001
| sPTB Outcome and NEFA Tertilea | No. of sPTBs | % | Crude OR | Adjusted ORb | 95% CI |
|---|---|---|---|---|---|
| sPTB at <37 weeks (n = 115) | |||||
| Tertile 1 | 33 | 29.2 | 1.0 | 1.0 | Referent |
| Tertile 2 | 33 | 29.7 | 1.03 | 1.12 | 0.61, 2.05 |
| Tertile 3 | 49 | 43.4 | 1.86 | 2.02 | 1.13, 3.48 |
| sPTB at 34– 36 weeks (n = 82) | |||||
| Tertile 1 | 26 | 23.0 | 1.0 | 1.0 | Referent |
| Tertile 2 | 24 | 21.6 | 0.9 | 1.17 | 0.53, 2.00 |
| Tertile 3 | 32 | 28.3 | 1.53 | 1.03 | 0.90, 3.27 |
| sPTB at <34 weeks (n = 33) | |||||
| Tertile 1 | 7 | 6.2 | 1.0 | 1.0 | Referent |
| Tertile 2 | 9 | 8.1 | 1.32 | 1.47 | 0.48, 4.53 |
| Tertile 3 | 17 | 15.0 | 3.04 | 3.73 | 1.33, 10.44 |
Abbreviations: CI, confidence interval; NEFA, nonesterified (free) fatty acid; OR, odds ratio; sPTB, spontaneous preterm birth.
a Lowest tertile, <0.19 mmol/L; middle tertile, 0.19–<0.33 mmol/L; highest tertile, ≥0.33 mmol/L.
b Adjusted for maternal age, race, prepregnancy body mass index, family history of preeclampsia, periconceptional multivitamin use, and smoking.