Birth Outcomes, Adjusteda Mean Differences, and Adjusted Relative Risks by Maternal Exposure Time to Improved Stove During Pregnancy, Trial 1, Rural Nepal, N=2379
| Time During Pregnancy Mother Exposed to New Stove, % | |||||
|---|---|---|---|---|---|
| 0 | <33 | 33–65 | 66–99 | 100 | |
| Number of infants gestational age recorded | 943 | 165 | 141 | 125 | 474 |
| Gestational age, mean (SD),b week | 38.6 (2.7) | 38.4 (3.1) | 39.2 (2.0) | 38.8 (2.7) | 38.5 (2.7) |
| Gestational age,b mean difference (95% CI), week | Reference | −0.51 (−1.03, 0.01) | 0.27 (−0.30, 0.85) | −0.24 (−0.87, 0.39) | −0.75 (−1.36, −0.14) |
| Preterm, % | 22.5 | 23.6 | 13.5 | 21.6 | 22.2 |
| Preterm,b RR (95% CI) | 1.00 | 1.38 (0.97, 1.97) | 0.81 (0.50, 1.32) | 1.41 (0.91, 2.20) | 1.66 (1.08, 2.57) |
| Number of infants with birth weight measured | 588 | 133 | 116 | 104 | 360 |
| Birth weight, mean (SD),c g | 2630 (443) | 2628 (443) | 2647 (418) | 2676 (408) | 2657 (439) |
| Birth weight,c mean difference (95% CI), g | Reference | −12.8 (−107.1, 81.4) | −7.7 (−112.7, 97.4) | 28.9 (−87.2, 145.0) | −5.5 (−122.6, 111.6) |
| Low birth weight, % | 38.6 | 39.9 | 30.2 | 33.7 | 32.2 |
| Low birth weight,c RR (95% CI) | 1.00 | 1.08 (0.82, 1.41) | 0.83 (0.59, 1.17) | 0.92 (0.63, 1.34) | 0.92 (0.65, 1.30) |
| Number of infants with both gestational age and birth weight recorded | 522 | 118 | 102 | 93 | 331 |
| Gestational age, mean (SD),d week | 38.7 (2.6) | 38.6 (25.6) | 39.2 (2.0) | 38.9 (2.8) | 38.4 (2.7) |
| Gestational age,d mean difference (95% CI), week | Reference | −0.39 (−1.01, 0.22) | 0.16 (−0.53, 0.84) | −0.28 (−1.03, 0.47) | −0.97 (−1.73, −0.20) |
| Preterm,d % | 20.7 | 22.0 | 12.8 | 20.4 | 23.3 |
| Preterm,d RR (95% CI) | 1.00 | 1.41 (0.91, 2.18) | 0.84 (0.46, 1.53) | 1.51 (0.86, 2.62) | 2.01 (1.13, 3.56) |
| Small for gestational age, % | 47.5 | 52.5 | 55.9 | 50.5 | 44.1 |
| Small for gestational age,d, RR (95% CI) | 1.00 | 1.14 (0.90, 1.44) | 1.21 (0.95, 1.54) | 1.11 (0.83, 1.48) | 1.00 (0.74, 1.34) |
Abbreviations: CI, confidence interval; RR, relative risk; SD, standard deviation.
↵a Adjusted for secular trend (cubic spline every 100 days) and sex of infant.
↵b Gestational age includes any measures 24 to <43 weeks (5.8% of gestational ages fell outside this range).
↵c Birth weight includes all measured within 72 hours.
↵d Gestational age and preterm among those with birth weights within 72 hours of birth.