Physical activity among pregnant inpatients and outpatients and associations with anxiety

Objective: Physical activity is linked to lower anxiety, but little is known about the association during pregnancy. This is especially important for antepartum inpatients, who are known to have increased anxiety yet may not be able to achieve target levels of physical activity during hospitalization. We compared physical activity metrics between pregnant inpatients and outpatients and explored correlations with anxiety.

Materials and methods: This was a prospective cohort between 2021 and 2022 of pregnant people aged 18-55 years carrying singleton gestations ≥ 16 weeks. Three exposure groups were matched for gestational age: 1) outpatients from general obstetric clinics; 2) outpatients from high-risk Maternal-Fetal Medicine obstetric clinics; and 3) antepartum inpatients. Participants wore Actigraph GT9X Link accelerometer watches for up to 7 days to measure physical activity. The primary outcome was mean daily step count. Secondary outcomes were metabolic equivalent tasks (METs), hourly kilocalories (kcals), moderate to vigorous physical activity (MVPA) bursts, and anxiety (State-Trait Anxiety Inventory [STAI]). Step counts were compared using multivariable generalized estimating equations adjusting for maternal age, body-mass index, and insurance type as a socioeconomic construct, accounting for within-group clustering by gestational age. Spearman correlations were used to correlate anxiety scores with step counts.

Results: 58 participants were analyzed. Compared to outpatients, inpatients had significantly lower mean daily steps (primary outcome, adjusted beta -2185, 95 % confidence interval [CI] -3146, -1224, p < 0.01), METs (adjusted beta -0.18, 95 % CI -0.23, -0.13, p < 0.01), MVPAs (adjusted beta -38.2, 95 % CI -52.3, -24.1, p < 0.01), and kcals (adjusted beta -222.9, 95 % CI -438.0, -7.8, p = 0.04). Over the course of the week, steps progressively decreased for inpatients (p-interaction 0.01) but not for either of the outpatient groups. Among the entire cohort, lower step counts correlated with higher anxiety scores (r = 0.30, p = 0.02).

Conclusion: We present antenatal population norms and variance for step counts, metabolic equivalent tasks, moderate to vigorous physical activity bursts, and kcals, as well as correlations with anxiety. Antepartum inpatients had significantly lower physical activity than outpatients, and lower step counts correlated with higher anxiety levels. These results highlight the need for physical activity interventions, particularly for hospitalized pregnant people.