Background
Maternal depression is a serious public health issue [
1]. Depressive symptoms are marked by an extended sense of sad mood, loss of interest, tearfulness, sleep problem, restlessness, irritability, appetite disturbance, and even suicidal ideation or attempt [
2]. Previous studies suggested that depressive symptoms were found among about 10% to 20% of mothers, and such symptoms can last for several months or even a year [
3]. Depression can happen at any time throughout the whole pregnancy process, from early pregnancy to even after delivery [
4]. Antenatal depression itself is an important risk factor for maternal depression at other time-points for pregnant women as well [
4]. Furthermore, due to the unique role of mothers in caring their babies, previous studies suggested that children of depressive mothers are three times more likely to develop serious emotional problems [
5,
6].
A lot of studies have been done to explore the risk factors of maternal depression [
7‐
9]. Recent reviews suggested that SC is a protective factor for individuals
’ mental health status and it could also significantly reduce the risk of antenatal and postpartum depression [
10‐
12]. SC is defined as
“features of social organization, such as trust, norms and networks that can improve the efficacy of society by facilitating coordinated actions
” [
13]. It comprises two components, namely the cognitive SC and the structural SC [
14]. The cognitive component refers to the internally subjective aspects of SC that reflect people’s perceptions on the level of interpersonal trust, sharing, reciprocity and other norms [
15,
16]. The structural capital is more about the externally objective dimension and is featured by behavioral expression of social network and individual participation or community activities [
17]. Till date, most studies on SC are cross-sectional in nature. In order to further explore the relationship between SC and maternal depression, a follow-up study design was used in the current study with both cognitive and structural SC being measured at the individual level.
The fourth baby boom period in China is approaching, as a result the number of women at their reproductive age is increasing rapidly, with an increment of about 2 million per year [
18]; and a majority of them are the first generation of babies after the one-child policy was implemented [
18,
19]. This group is very special, in the sense that they are the only child in their family and as a result most of them are
‘spoiled
’. Moreover, a majority of them will be parents for the first time. In the traditional Chinese culture, parturients should practice “sitting the month” after their delivery, a period where they should stay at home for about one or two months to recover after they discharge from the hospital [
20,
21]. This practice could bring huge changes on the life style and social environment of the parturients during this period. On one hand, primiparas need to adjust to get used to their new roles as mothers; meanwhile, the focus of the whole family will suddenly move towards the baby. These changes could result in a sudden drop of emotional support perceived by the primiparas [
22]. On the other hand, “sitting the month” will limit their social activities, which will ultimately lower their perceived social support levels [
19,
22]. Other than the above-mentioned issues, a lot of families nowadays also need older generations
’ input (e.g. grandparents of the baby) while taking care of the babies. This arrangement has a high potential to cause cross-generation conflicts, which poses another potential risk towards the primiparas. Thus it is not surprising that about 50% to 75% of primiparas in China had reported experiences of unstable mood, accompanying by different level of physical symptoms in China [
19].
To the best of our knowledge, there are very few studies had explored the relationships between SC and maternal depression at different time-points throughout the pregnancy progress. Using a sample of Chinese primiparas, the current study aims to answer the above question through a follow-up study design. We hypothesized that SC level of primiparas will be negatively correlated with depression among Chinese primiparas [
10‐
12].
Methods
Study design
This study was conducted from March to December 2016 in the largest maternity hospital in Zhejiang Province, China. New mothers admitted to the hospital during the recruitment period were approached by the study team. Those who were willing to join the study were then assessed for their eligibility. To be included in the study, the primiparas should meet the following criteria: 1) in the hospital for the prenatal checkup, 2) 18 years old and above, 3) being pregnant for 30–36 weeks pregnant, 4) planning to give birth and attend postpartum follow up at the hospital, 5) willing to participate in the study, 6) literate in Chinese, and 7) not suffering from cognitive deficit. A total of 450 subjects were recruited for the current study and following informed voluntary written consent. The participation was voluntary, and they were informed that ‘refusal to participate will not affect the care they are going to receive from the hospital’. This study was approved by the Ethics Board of the Hangzhou Normal on 4th March 2016 (reference no.: ISRCTN2016014).
Data were collected at three different time-points: 1) T1 - while the participants were recruited at their 30–36 weeks of pregnancy in the antenatal clinical; T2 - at their 2nd or 3rd days in the wards after the delivery; T3 - at week 6 to 8 after the delivery in the postpartum examination clinic. To enable easier administration, the survey was built using an e-platform, and a QR code was generated. By scanning this QR code using their mobile phones, individuals could access to the full questionnaire including the socio-demographics and scales to evaluate primiparas’ SC and depressive symptoms. And they could choose the time point (i.e. T1, T2 and T3) and completed the survey on their mobile phones. This QR code was stuck onto the casebook of each participant, enabling the data collectors to easily identify the participants while they were in the hospital. In the case that the primiparas forgot to fill in the survey, phone calls were made by the investigators to remind them to scan that QR code to fill in the e-questionnaire. More detailed information regarding the measurement scales were included as the following.
Measurements
SC was measured by the Chinese version of SC Assessment Questionnaire (C-SCAQ) [
23]. This questionnaire was developed by Zhou and colleagues among Chinese primiparas based on the World Bank
’s SC Assessment Tool and Bian
’s Chinese position Table [
24,
25]. More details of the C-SCAQ and tis development and validation could be found in Zhou et al. [
23]. The C-SCAQ can be used to measure primipraras
’ SC on both the cognitive and structural domains. Cognitive SC includes the social trust (ST) and social reciprocity (SR) sub-scales. The ST sub-scale has 8 items in total, and it measures the generalized trust among colleagues, neighbors and strangers. The SR consists of 7 items, and assesses the reciprocity among colleagues, neighbors and strangers. The score for each item varies from 1 to 5. The structural SC domain covers social network (SN) and social participation (SP). SN is assessed using Bian
’s Chinese position Table [
25], which considers Chinese social characteristics by position generator method. SN includes network diversity (the sum of occupations of the social network members) score ranging from 0 to 20, upper reach ability (the highest prestige occupation scores of social network members) score ranging from 0 to 95, and network range (the highest prestige occupation scores minus the lowest score of social network members) score ranging from 0 to 94. The SP has 11 items, covering the activity types, motivation and involvement. The items of activity types and motivation were graded using a 5-point Likert scale, while involvement was coded with 0 (nonparticipation) and 1 (participation). Since the internal measurement units are not uniform, the standardized score of SN and SP were used. Higher score represents higher SC level. The Cronbach
’ α of cognitive and structural SC dimensions of C-SCAQ were 0.773 and 0.902 respectively in the previous study [
26].
Depressive symptoms were measured by the Chinese version of Edinburgh Postnatal Depression Scale (C-EPDS). The scale consists of 10 items with 4 alternative answers for each item. The score for each item varies from 0 to 3, with a maximum score of 30 [
27]. C-EPDS has been tested and validated among Chinese pregnant women before [
28]. Compared to the Diagnostic and Statistical Manual of Mental Disorder-IV diagnosis of major depression as reference, C-EPDS demonstrated good reliability with a cutoff point score of 9 and above (sensitivity 0.72, specificity 0.88) [
27]. This scale has also been used in other Chinese studies and showed high reliability in measuring prenatal and postnatal women’s depression [
29,
30]. In the current study following the evidences, a cut-off of 9 was used to indicate the status of having depressive symptoms.
Statistical analyses
Data were entered through EpiData 3.1 and analyzed by SPSS 20.0 (SPSS Inc., Chicago, IL, USA). We firstly described the socio-demographic characteristics of the sample. The participants were divided into two groups based on EPDS scores: the Depression group (score ≥ 9) and the Non-depression group (score < 9). The SC was compared between these two groups using T tests. Separate binary logistic regressions were conducted to assess the relationships between SC and depression at each of the three time-points, with the C-EPDS score being the dependent variable, and SC factors being the independent variables. The covariates in every regression included: age, district, education level, character, planned pregnancy, incoming per month, delivery by cesarean section, relationship with husband, relationship with parents-in-law, and sleep. In all regressions, a two-side p-value below 0.05 was treated as statistically significant.
Conclusions
We examined the association of SC and maternal depression among Chinese primiparas. The prevalence of EPDS had a “V” type distribution and SC form an upside-down “V”. The two curves of structural SC had larger fluctuations than curves of cognitive SC. The SC level of Depression group was lower than Non-depression group at all three time-points. ST and SN were significantly associated with the depression of primiparas at T1, ST was associated at T2, and ST and SP were associated at T3. For future maternal health education and promotion programs, more attention could be given to SC improvement in the community pregnancy health care management.