Postpartum PA under mild lockdown in Japan
The total PA of participants was 19.3 MET h/wk, and the percentage of adults aged 18 to 64 years who achieved the recommended PA of 23 MET h/wk as advocated by the Japanese Ministry of Health, Labor and Welfare was 28.6%. Reportedly, 17.2% of Japanese women in their 30s achieved the recommended PA, lower than in other generations [25], and women in the child-rearing generation tend to show lower PA. In this study, the percentage of low activity level in the IPAQ was 45.9%, indicating that participants in this study was more active compared to a previous study of Japanese postpartum women (92.0%) [26].
Factors influencing PA in postpartum women
This study investigated the relationship between postpartum PA and psychosocial aspects during the COVID-19 pandemic. The results showed that the factors most affecting total PA correspond to anxiety screening with GAD-2 and correlated inversely with total PA. Longer duration after childbirth and multiparity were shown to have positive effects on PA levels. Moreover, women who have someone with whom they can talk to about work and family life had higher total PA.
A new finding from this study was that anxiety symptoms during the COVID-19 pandemic exert negative effects on the PA of the postpartum women. From the time the pandemic was declared in March 2020, activities of daily living were restricted at social and individual levels, representing a source of mental health problems [2, 3, 5]. According to a systematic review of pregnant and postpartum women, the prevalence of mental health disorders after the pandemic started was higher than before the pandemic for both anxiety (40%) and depression (27%), with high prevalence of anxiety both during pregnancy and in the postpartum period [2]. Participants in this study gave birth after March 2020, once the epidemic had been declared a pandemic, and thus were affected by the pandemic during the major life events of pregnancy, childbirth, and early childcare. Increased sedentary time and screen time and physical inactivity during the COVID-19 pandemic represent contributors to worsened mental health [9], suggesting that early detection through screening and intervention are needed.
In the time after delivery, total PA at 12 months postpartum reportedly increased by 1 MET h/wk compared with 3 months postpartum, with a higher percentage of PA from going out in association with childcare and family activities [7]. Opportunities to go out increase as the child grows, which is conjectured to increase PA. In addition, the depressive symptoms that are a factor inhibiting PA decrease with time after childbirth [4] and physical recovery is expected [27], which suggests that activity may be facilitated.
Although a number of studies have examined relationships between parity and PA, no consensus has been obtained [10, 20, 28, 26]. In this study, multiparity showed an association with higher total PA. The latest study using the Pregnancy Physical Activity Questionnaire [28, 29], which includes question items that reflect the lives of women during the child-rearing period, was conducted from December 2019 to September 2021 in Poland [30]. In that study, multiparous women were found to have spent more energy on total PA and household activities, and significantly less on sports and passive rest during the third trimester of pregnancy compared to primiparas. Therefore, multiparous women may engage in higher amounts of PA in association with caring for older children (taking them to and from places, playing in the park, etc.).
In a number of previous studies, childcare support was given as a factor promoting PA, so this study obtained answers for “Number of people who share regular childcare activities” and “Having someone you can talk to with about work and home life?” as childcare support questions. The mean number of persons who shared in childcare duties was 1.3 and 81.2% of respondents had someone with whom they could talk. These women with someone to whom they could talk were found to have higher total PA than women without such a relationship. Previously, a lack of social supports for childcare was indicated to negatively affect PA and mental health [5, 10, 20]. In a survey on social supports and postpartum depression, the incidence of postpartum depression was 7.5% in a group able to consult with a partner or other person, 36.9% in a group unable to consult with their partner but able to consult with another person, and 63.6% in a group unable to consult with anyone, suggesting the importance of emotional support [31]. In the current pandemic, measures were taken to ensure social distancing as a method of infection control. Under such the circumstances, receiving support from relatives and people nearby is likely to be much more difficult compared before the pandemic. Meanwhile, mothers with high social support scores even during the COVID-19 epidemic were reported to exhibit better psychological states than mothers with low scores [32]. As mentioned previously, given the relationship between worsening mental state and physical inactivity, against a backdrop of mental health stressors brought on by a pandemic, the existence of someone with whom to consult provides a support to mothers and is also thought to produce positive effects on PA.
PA level and HRQoL
The Active group showed higher SF-12v2 scores than the Inactive group. This suggests that mothers with a high PA level have higher HRQoL, supporting a review of 55 papers on the relationship between PA and QoL, which concluded that a uniform positive relationship exists between PA level and HRQoL [33]. SF-12v2 standard values for Japanese women in their 30s are as follows: mean PCS, 51.7 (SD 7.7), interquartile range (IQR) 47.1–54.3; mean MCS, 47.4 (SD 9.4), IQR 41.7–48.5. In both groups, PCS was lower than the mean for the general population of the same age and the Inactive group showed a value close to the 25th percentile, suggesting the presence of a certain level of physical discomfort. Moreover, differences in summary score due to activity level were more marked for physical health (3.2 points) than for mental health (1.3 points), representing a similar result to that of a previous study that identified a strong relationship between activity level and physical health. The WHO recommends engaging in moderate PA for ≥ 150 min each week during the postpartum period [34]. In randomized control trials on PA recommended by the WHO, postpartum women who performed continuous PA showed improvements in HRQoL from before to after the interventions [35, 36]. The Active group included women who met one of the following criteria: 1) vigorous PA for ≥ 20 min, ≥ 3 days/week; 2) moderate PA or walking ≥ 30 min, ≥ 5 days/week; or 3) PA on ≥ 5 days/week for total activity of ≥ 10 MET h/wk. Thus, mothers who are able to perform PA continuously throughout the week appear better able to maintain physical and mental health than mothers who are not.
Findings to promote postpartum PA
The perception of anxiety under the COVID-19 pandemic appears to contribute to physical inactivity not only in postpartum women, but also in the general population. Nagata et al. suggested that anxiety about disrupting social harmony by spreading the infection or going out makes Japanese people more inactive [21]. Postpartum women taking care of an infant in such social situations appear likely to experience even more diverse anxieties. The GAD-2 used in screening for anxiety symptoms in this study has been suggested to be related to physical inactivity and may be useful for identifying subjects in need of more support. Continuous examination of factors facilitating PA, with a focus on variables examined in this study, such as primiparity and women with a shorter postpartum period, would help promote postpartum PA.