Physical Activity and Its Relationship with Preterm Birth in the Presence of Depressive Symptomology.

Objective: To examine the relationship between physical activity (PA) and preterm birth (PTB) within the context of depressive symptoms (DS).

Methods: Data are from the Life-course Influences of Fetal Environments (LIFE) Study, a cohort comprised of 1410 Black women, age 18-45 years who delivered a singleton in Metropolitan Detroit, MI. DS were measured with the Center for Epidemiologic Studies Depression Scale (CES-D); a score > 23 indicates severe DS. Traditional leisure time PA (LTPA) and non-LTPA during pregnancy (walking for a purpose, climbing stairs) were both measured. Modified Poisson regression models were used to estimate the association between PTB and PA. Effect modification by severe DS was assessed via stratification.

Results: Approximately 16% of women had a PTB; 20% had CES-D scores > 23. Walking for a purpose was the most frequently reported type of PA (79%), followed by any LTPA (37.7%) and climbing stairs (13.5%). Compared with women who reported no PA, women who reported walking for a purpose (PR = 0.70, 95% CI 0.61, 1.10), partaking in LTPA (PR = 0.67, 95% CI 0.50, 0.90), or climbing stairs (PR = 0.61, 95% CI 0.45, 0.81) were less likely to have PTB. Results stratified by severe DS show the association between LTPA and PTB was more pronounced in women with severe DS, while the non-LTPA relationship with PTB was more heterogeneous.

Conclusions: Women who participated in traditional LTPA (any or walking only) and non-LTPA experienced improved birth outcomes. LTPA may buffer against PTB among pregnant Black women with severe DS as well as none or mild DS.