Activity Restriction and Hospitalization in Pregnancy: Can Bed-Rest Exercise Prevent Deconditioning? A Narrative Review

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.

Impact of Physical Activity Interventions on High-Risk Pregnancies: A Systematic Review and Meta-Analysis

Pregnant women with absolute contraindications may be advised against physical activity throughout pregnancy. In this context, bed rest elevates the short-term risk of neonatal complications, thereby exacerbating negative long-term effects on childhood development. The aim of the current study was to investigate the impact of various physical activity interventions during bed rest or activity restriction in pregnancy on factors such as birth weight, preterm birth, maternal hypertension, gestational age at delivery, and the incidence of cesarean sections. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review was designed. The protocol was registered in the International Prospective Registry of Systematic Reviews (PROSPERO) (CRD42022370875). Nine studies, with a total sample of 3173 women, from six countries on four continents were included. There were significant differences in the relationship between bed rest status and birth weight (Z = 2.64; p = 0.008) (MD = 142.57, 95% CI = 36.56, 248.58, I2 = 0%, Pheterogeneity = 0.45) favourable to active groups. No significant differences were found in other analyzed outcomes. Pregnant women who experience this problem must maintain a minimum of daily activity to alleviate these physiological complications and the medical field must understand the consequences of physical inactivity during pregnancy.

Prenatal immobility stress: Relationship with oxidative stress, inflammation, apoptosis, and intrauterine growth restriction in rats

BACKGROUND

Prenatal stress is a significant risk factor affecting pregnant women and fetal health. In the present study, we aimed to investigate the effect of immobility stress at different periods of pregnancy on oxidative stress, inflammation, placental apoptosis and intrauterine growth retardation in rats.

METHODS

Fifty adult virgin female Wistar albino rats were used. Pregnant rats were exposed to 6 h/day immobilization stress in a wire cage at different stages of pregnancy. Groups I and II (Day 1-10 stress group) were sacrificed on the 10th day of pregnancy, and Group III, Group IV (10-19th-day stress group), and Group V (1-19th-day stress group) were sacrificed on the 19th day of pregnancy. Inflammatory cytokines, including interleukin-6 (IL-6) and interleukin-10 (IL-10), serum corticotropin-releasing hormone (CRH), and corticosterone levels were measured by enzyme-linked immunosorbent assay. Malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT) levels in the placenta were spectrophotometrically measured. Histopathological analyses of the placenta were evaluated by hematoxylin and eosin staining. Tumor necrosis factor-alpha (TNF-α) and caspase-3 immunoreactivity in placenta tissues were determined by the indirect immunohistochemical method. Placental apoptosis was determined by the TUNEL staining method.

RESULTS

We found that the immobility stress during pregnancy significantly increased serum corticosterone levels. Our results showed that the immobility stress diminished the number and weight of fetuses in rats compared to the non-stress group. The immobility stress caused significant histopathological changes in the connection zone and labyrinth zone and increased placental TNF-α and caspase-3 immunoreactivity and placental apoptosis. In addition, immobility stress significantly increased the levels of pro-inflammatory IL-6 and MDA and caused a significant decrease in the levels of antioxidant enzymes such as SOD, CAT, and anti-inflammatory IL-10.

CONCLUSIONS

Our data suggest that immobility stress causes intrauterine growth retardation by activating the hypothalamic-pituitary-adrenal axis and deteriorating placental histomorphology and deregulating inflammatory and oxidative processes.