TABLE 3.
Adjusteda mean differences [95% confidence intervals (CI)s] in body composition at age 5 years and change in body composition from birth to 5 years by pre-conception, prenatal, and postnatal exposure to secondhand smoke
| Exposure window | n | Adjusted mean difference (95% CI) | p-value | |
|---|---|---|---|---|
| Adiposity at 5 years (% fat mass) | ||||
| 1 | Pre-conception | 568 | 1.7 (0.1, 3.6) | 0.07 |
| 2 | 17 weeks gestation | 63 | −0.7 (−4.3, 2.9) | 0.70 |
| 3 | 27 weeks gestation | 360 | −0.3 (−1.8, 1.1) | 0.63 |
| 4 | Delivery | 563 | 2.5 (−0.9, 5.9) | 0.14 |
| 5 | 5 months of age | 568 | 1.7 (0.1, 3.2) | 0.04 |
| 6 | 18 months of age | 517 | 0.9 (−0.6, 2.5) | 0.24 |
| 7 | 5 years of age | 518 | −0.3 (−1.5, 0.9) | 0.62 |
| p for interaction = 0.17 | ||||
| Fat mass (kg) | ||||
| 1 | Pre-conception | 568 | 0.3 (−0.1, 0.8) | 0.15 |
| 2 | 17 weeks gestation | 63 | −0.2 (−1.1, 0.7) | 0.63 |
| 3 | 27 weeks gestation | 360 | −0.3 (−0.7, 0.1) | 0.14 |
| 4 | Delivery | 563 | 0.5 (−0.3, 1.3) | 0.21 |
| 5 | 5 months of age | 568 | 0.3 (−0.2, 0.7) | 0.21 |
| 6 | 18 months of age | 517 | 0.1 (−0.3, 0.5) | 0.53 |
| 7 | 5 years of age | 518 | −0.1 (−0.5, 0.2) | 0.41 |
| p for interaction = 0.22 | ||||
| Fat-free mass (kg) | ||||
| 1 | Pre-conception | 568 | −0.2 (−0.7, 0.3) | 0.38 |
| 2 | 17 weeks gestation | 63 | −0.3 (−1.2, 0.6) | 0.49 |
| 3 | 27 weeks gestation | 360 | −0.4 (−0.9, 0.0) | 0.08 |
| 4 | Delivery | 563 | −0.8 (−1.5, −0.1) | 0.03 |
| 5 | 5 months of age | 568 | −0.3 (−0.8, 0.1) | 0.14 |
| 6 | 18 months of age | 517 | −0.2 (−0.7, 0.3) | 0.45 |
| 7 | 5 years of age | 518 | −0.2 (−0.5, 0.2) | 0.31 |
| p for interaction = 0.48 | ||||
| Change in adiposity from birth to 5 years (% fat mass) | ||||
| 1 | Pre-conception | 517 | 3.1 (1.0, 5.1) | <0.01 |
| 2 | 17 weeks gestation | 56 | −2.5 (−6.7, 1.7) | 0.24 |
| 3 | 27 weeks gestation | 331 | 0.5 (−1.1, 2.2) | 0.53 |
| 4 | Delivery | 517 | 4.0 (0.4, 7.6) | 0.03 |
| p for interaction = 0.01 | ||||
| Change in fat mass from birth to 5 years (kg) | ||||
| 1 | Pre-conception | 517 | 0.5 (0.0, 1.0) | 0.05 |
| 2 | 17 weeks gestation | 56 | −0.5 (−1.4, 0.5) | 0.33 |
| 3 | 27 weeks gestation | 331 | −0.2 (−0.6, 0.2) | 0.23 |
| 4 | Delivery | 517 | 0.6 (−0.1, 1.4) | 0.11 |
| p for interaction = 0.02 | ||||
| Change in fat-free mass from birth to 5 years (% fat mass) | ||||
| 1 | Pre-conception | 517 | −0.2 (−0.8, 0.3) | 0.40 |
| 2 | 17 weeks gestation | 56 | −0.2 (−1.1, 0.7) | 0.68 |
| 3 | 27 weeks gestation | 331 | −0.3 (−0.8, 0.1) | 0.18 |
| 4 | Delivery | 517 | −0.7 (−1.4, 0.1) | 0.09 |
| p for interaction = 0.46 | ||||
a
Adjusted for infant sex, maternal race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other), maternal education (<high school degree, high school degree, some college), pre-pregnancy body mass index (kg/m2), maternal diet quality during pregnancy (according to continuous Healthy Eating Index scores), duration of exclusive breastfeeding (<5 months, >5 months), and age at body composition (years).
Note: The bolded text signifies statistical significance (p < 0.05).