Table 3.
Unadjusted and Adjusted Associations Between Physical Activity During Pregnancy and Preterm Delivery, Stratified by Study Enrollment Period: Baltimore Preterm Delivery Study (2001–2004)
| Physical Activity Type* | Prenatal (n = 456)
|
Postpartum (n = 376)
|
||||||
|---|---|---|---|---|---|---|---|---|
| Unadjusted
|
Adjusted
|
Unadjusted
|
Adjusted
|
|||||
| PR | 95% CI | PR | 95% CI | PR | 95% CI | PR | 95% CI | |
| Any LTPA† | ||||||||
| No (Referent) | ||||||||
| Yes | 0.83 | 0.53, 1.29 | 0.92 | 0.57, 1.49 | 0.76 | 0.47, 1.25 | 0.79 | 0.47, 1.34 |
| LTPA (min/wk)‡ | ||||||||
| 0 (Referent) | ||||||||
| 1–60 | 0.67 | 0.38, 1.17 | 0.76 | 0.42, 1.37 | 0.96 | 0.57, 1.61 | 1.21 | 0.68, 2.13 |
| >60 | 1.19 | 0.66, 2.14 | 1.33 | 0.70, 2.53 | 0.37 | 0.12, 1.13 | 0.25 | 0.06, 0.98 |
| Stair climbing (times/d)§ | ||||||||
| ≤10 (Referent) | ||||||||
| >10 | 1.00 | 0.64, 1.54 | 0.96 | 0.61, 1.50 | 0.85 | 0.51, 1.44 | 0.65 | 0.36, 1.16 |
| Walking for a Purpose (min/d)|| | ||||||||
| ≤30 (Referent) | ||||||||
| >30 | 0.69 | 0.42, 1.13 | 0.62 | 0.37, 1.05 | 0.72 | 0.42, 1.23 | 0.63 | 0.36, 1.13 |
Abbreviations: CI, confidence interval; LTPA, leisure time physical activity; PR, prevalence ratio.
*
Intensity of LTPA omitted owing to sparse data.
†
Adjusted for drug use, cigarette smoking (2nd trimester), locus of control, family resource scale.
‡
Adjusted for locus of control, family resource scale.
§
Adjusted for locus of control, family resource scale, cigarette smoking, drug use.
||
Adjusted for drug use, locus of control, family resource scale.