Accelerometer measurements of physical activity in pregnant adolescents
Date
2019
Authors
Clark, Emma L. M., author
Shomaker, Lauren B., advisor
Lucas-Thompson, Rachel, committee member
Leach, Heather, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
In adult women, physical activity during pregnancy, assessed objectively with accelerometry, has been related to less excess gestational weight gain and better health outcomes for mother and child. Objectively-measured physical activity has not been reported in pregnant adolescents, and it is unclear to what extent accelerometers are feasible in this group of young women who are at very high-risk for social-emotional challenges and excess gestational weight gain. The main purpose of the current thesis project was to investigate the feasibility of using accelerometers to objectively quantify physical activity in pregnant adolescents. The second aim was to explore the associations of physical activity with pregnant adolescent health characteristics including pre-pregnancy body mass index (BMI; kg/m2), first-trimester weight (kg), depression symptoms, emotional eating, and loss-of-control eating. Participants were N = 28 15-19 year old patients, 12-18 weeks gestation, obtaining prenatal care at a multidisciplinary adolescent pregnancy clinic. Physical activity was assessed with GT3-X wrist-worn accelerometers for 7 days to assess average moderate-vigorous physical activity (MVPA) per day, percentage of time spent in MVPA, daily average sedentary bouts, percent of time spent sedentary, average step counts, and maximum step counts. Feasibility was determined as median days of wear time equal to or exceeding 4 out of 7 days (of≥10 hours of wear time per day). Adolescents reported pre-pregnancy weight/height to compute pre-pregnancy BMI; first-trimester weight was assessed from measured weight. Depression symptoms and emotional eating were assessed with validated self-report questionnaires. Presence of loss-of-control eating was evaluated by interview. In addition to reporting statistical significance (p < .05), strength of bivariate associations were described as moderate (r ≥ .40) and large (r ≥ .60), given the pilot nature of the study. Results indicated that the median days of valid wear was 5 days, and 59.3% of pregnant adolescents met criteria for valid wear. Adolescents who did not have valid accelerometer reported heavier pre-pregnancy BMI (28.63 ± 6.75 kg/m2 vs. 23.55 ± 5.21 kg/m2, p = .04), with no other significant differences. Among pregnant adolescents with valid data (N = 16), there was an inverse, moderate association of average MVPA per day with depression symptoms (r = -.44 p = .09). In conclusion, there were mixed results for the feasibility of accelerometry in pregnant adolescents. In order to increase wear time compliance in this population, particularly for heavier adolescents, more incentives are required. Finally, results from this study suggest that the connection between pregnant adolescents' physical activity and depression warrants exploration in future research.