To the best of our knowledge, this study was the first to examine the psychological response of postpartum mothers during the COVID-19 pandemic in a metropolitan area of Japan. The total EPDS and MIBS scores did not differ significantly among the three Before COVID-19 and the During COVID-19 groups. However, when the subscales of the EPDS were examined using MANOVA, the subscales related to anxiety factor were significantly higher in the During COVID-19 group, while the subscales related to depression and anhedonia factors, except for thoughts of self-harm, were lower in the During COVID-19 group.
COVID-19 as a disaster
Although an established definition of ‘disaster’ does not exist, disasters have been said to have three important characteristics. The first is a threat of harm or death to many people. The second is a disruption in social processes, services, and networks. And the third is an effect on mental and physical outcomes. The COVID-19 pandemic can be defined as a worldwide disaster [43]. Exposure to disasters has been associated with various mental health problems, including posttraumatic stress disorder, major depressive disorder, substance use disorder, and generalized anxiety disorder. Reportedly, women are less likely to be resilient during the post-disaster period than men, regardless of the type of disaster [44]. People living with children are also less likely to be resilient, perhaps because of their concerns and responsibilities toward their children. Longitudinal studies have shown that post-disaster mental health problems generally peak within a year and then improve, but in some people the symptoms persist [45]. However, COVID-19 is an ongoing disaster with no sign of a worldwide end. Therefore, mental health problems may become more serious in the future. The present study may serve as an important resource for clarifying the longitudinal course of postpartum maternal mental health during the COVID-19 pandemic.
COVID-19-related anxiety
Our survey revealed that during the COVID-19 pandemic, new mothers had higher levels of anxiety than those who gave birth before COVID-19. Pregnancy and childbirth can be stressful times for women even during normal circumstances; factors related to the COVID-19 pandemic may have further increased pregnancy- and childbirth-related anxiety. Previous articles have suggested that many people were worried about transmitting COVID-19 to their families, and a certain number of people exhibited pathological health anxiety characterized by an excessive fear of COVID-19 [10, 46]. Furthermore, a recent study revealed that COVID-19-related health worries may exacerbate mental health problems among pregnant women [47]. In addition, the unpredictability and uncertainty of the COVID-19 pandemic may also increase anxiety. Given the high degree of transmissibility and potential lethality of COVID-19, we believe that anxiety levels increased because of concerns over transmitting COVID-19 to their newborn child and cognitive changes arising from alertness to potential threats.
Furthermore, COVID-19-related physical distancing might have led to social isolation, limited access to basic services, and decreased family and social support [30, 33]. In Japan, many women have been greatly influenced by the COVID-19 pandemic during the course of their pregnancy and postpartum period, including changes in the place of delivery (8%), the cancellation of planned formal or informal support (23%), and the cancellation of parenting classes (79%) [33, 34]. Our investigation might reflect COVID-19-related health worries and a lack of social support because of the COVID-19 pandemic. The increase in anxiety among peripartum women during the COVID-19 pandemic was consistent with the results of a previous meta-analysis [26]. Anxiety during the pregnancy period can reportedly have negative effects on a child’s mental development, internalizing problems, and cognitive function [48, 49]. Therefore, the current anxiety of perinatal women must be better understood, and an integrated approach to providing care is needed.
Relationships among anxiety, anhedonia, and depression
Our results showed that depression and anhedonia were lower during the COVID-19 pandemic, and this result seems to be inconsistent with previous studies [26, 27]. However, hypervigilance, which is a known feature of post-traumatic stress disorder, might be the key to interpreting these results [43, 44]. Hypervigilance is a physiological and cognitive state of persistent hyperarousal and alertness against potential threats that allows a threat to be easily detected and a quick response to be made in potentially dangerous situations [50]. Physiological factors (i.e., increased alertness) are said to be mediated by the activation of the neuroendocrine stress system [51]. Hyperarousal and alertness might be the opposite states of depression and anhedonia. If anxiety and stress regarding the threat posed by COVID-19 cause hypervigilance, then the relative reduction in depression and anhedonia might also reflect the influence of hypervigilance [50]. In the present study, the results were considered to be consistent with mental health during a disaster. The EPDS results appear to be largely interpretable based on the concept of hypervigilance with the possible exception of Item 7, which may be slightly inconsistent. Item 7 consists of insomnia, which should be exacerbated during the COVID-19 pandemic because insomnia is one of the characteristics of hypervigilance [50]. Other factors may have an impact on the improvement of apparent insomnia.
When hypervigilance becomes a chronic condition characterized by sustained activation and failure to deregulate warning responses, people may experience impairments in their quality of life, such as the exacerbation of depression and anhedonia. A previous longitudinal study using path analysis attempted to clarify the relationship among anhedonia, anxiety, and depression, and the results suggested that anxiety led to anhedonia and then to depression over time [52]. This study suggests that the chronic impact of the COVID-19 pandemic may lead to an eventual reverse in the downward trend of anhedonia and depression. The outcome will depend on multiple factors and the presence of resilience as a normal coping and adaption; thus, the changes associated with chronic courses should be followed continuously [53].
Of note, suicidal ideation (EPDS item 10), which is a component of the “EPDS Depression” factor, did not differ significantly between the Before and During COVID-19 groups, although the total depressive symptoms decreased during COVID-19. The suicide rate of peripartum women in Japan is estimated to be 8.7 per births of 100,000, which is higher than that in Western countries [54]. Furthermore, violent methods of suicide attempts are associated with critical perinatal outcomes [55]. Economic issues associated with the COVID-19 pandemic may also contribute to the exacerbation of suicidal ideation. Suicide ideation must be carefully considered because suicide attempts can lead to fatal consequences for both mother and child.
Above cut-off
The prevalence of postpartum depression in Western countries is estimated to be 13%–19% [56]. In Japan, a recent meta-analysis involving one hundred thousand Japanese women found that the prevalence of postpartum depression at one month after childbirth was 14.3% [57]. No significant difference in the prevalence of postpartum depression was seen between the three Before and the During COVID-19 groups, and the prevalence was almost equal to that reported in a recent Japanese meta-analysis [57]. As of December 2020, our results suggested that COVID-19 had little effect on the prevalence of postpartum depression and pathological maternal bonding.
Maternal bonding
MANOVA revealed only the score for MIBS Items 6 was significant difference between the four groups, however, post hoc comparison showed there were no significant difference in 2018 vs. 2020. Therefore, this difference does not seem to be important clinically. Previous studies have suggested that anxiety was negatively associated with mother-to-infant bonding and that depressive symptoms were predictors of future bonding [58, 59]. Since qualitative changes in the EPDS subscales have occurred, maternal bonding may change in the future. Moreover, as the COVID-19 pandemic becomes increasingly chronic, it may come to have a negative influence on maternal bonding.
Changes in mean scores of EPDS and MIBS throughout the COVID-19 pandemic
Figure 4 show the changes in the EPDS and MIBS scores throughout the COVID-19 pandemic. The increase in daily reported number of confirmed COVID-19 patients affected the psychological distress of the postpartum mothers and also caused social restrictions. A previous study in Wuhan showed that the prevalence of perinatal depression increased more as the COVID-19 pandemic worsened more [60]. However, our results showed that there was no changes of the average sum scores of the EPDS and MIBS. The third wave of COVID-19 cases has arrived in Japan since December 2020, and a state of emergency was issued again in January 2021 [42]. Because of the effects of chronic stress and the state of emergency, it is essential to observe future trends.
Community-based integrated care system and implementation
Possible barriers to the use of medical services must be considered. Middle-aged adults, women, and those who have experienced panic symptoms reportedly use mental health services less frequently after disasters [43]. In a UK study, women who died by suicide during the perinatal period were less likely to have contacted any psychiatric services before their suicide, compared with non-perinatal women [61]. In addition, because of the COVID-19 pandemic, mothers are being forced to restrict the use of medical services. During the COVID-19 pandemic, pregnant and postpartum women have experienced the cancellation of planned social support, and young people who had mental health problems were not able to access mental health support [34, 62].
Perceived supports provided by health care staff can be regarded as protective factors against stress-related symptoms [25]. Besides, a community-based integrated approach, including suicide prevention, may contribute to the maintenance of peripartum mothers’ mental health [63, 64]. Our results suggest the need to strengthen both general public health interventions and mental health care services during the COVID-19 pandemic. Suicide prevention for perinatal women is also important. Online support may be an optimal and effective option to assess each mother’s psychological and social needs, and such support might reduce psychological distress and prevent adverse effects on long-term mental health [33, 63, 65, 66].
Previous research has shown that an important factor associated with postpartum depression during the COVID-19 pandemic was immigration status [22]. Foreign nationals are unevenly distributed in metropolitan areas in Japan, and foreign nationals account for about four percent of the population in eastern Kanagawa [67]. We revealed that foreign nationals are less likely to contact appropriate services for mental illness; therefore, a community-based integrated care system that is accessible to foreign nationals during the perinatal period is also needed [68]. Further research is required to clarify individual responses and resilience, taking into account social, economic and cultural contexts.
Strengths and Limitations
Many of the studies that are currently being published have been conducted using online surveys because of convenience and COVID-19 precautions [9, 25, 34]. Online surveys inevitably encounter the problem of spoofing, which is detrimental to an accurate understanding of mental health. On the other hand, the screening questionnaire used in our study was completed face-to-face at the hospital by nurses or midwives. Furthermore, although a small number of missing data were excluded, this was a retrospective study of almost all the mothers who gave birth at one regional core medical institution. As a result, our study had a reduced sampling bias and might be a valuable resource for understanding the actual state of perinatal mental health in a metropolitan area of Japan during the COVID-19 pandemic. Moreover, one strength of this study is that the impact of COVID-19 was clarified by comparing the scores obtained during the pandemic with those obtained in a control group that reflected the situation before the COVID-19 pandemic [34].
Some limitations of this study should be noted. First, the causal relationship between the present results and the COVID-19 pandemic could not be established because the study consisted of a retrospective chart review. However, a yearly comparison strongly suggested that the changes in the mean scores for each item of the EPDS were caused by the COVID-19 pandemic. Second, we relied on information derived from self-reported measures, and the participants consisted of mothers visiting a single hospital. Third, this study did not examine potentially confounding factors affecting postpartum mental health, such as the current economic situation, social support, cultural context, and feelings toward pregnancy [22, 69]. Further studies to address these potentially confounding factors are needed.