Prevalence of postnatal depression and its early detection
Postnatal depression was originally thought to be absent in the Chinese populations because of the traditional practice of "peiyue support (doing the month)" during which additional social support is provided by the family for women in the first month after delivery . In 1998, Lee et al. found that the prevalence of PND in Chinese women six weeks after delivery was 5.5% which was relatively low as compared with studies of PND in non-Chinese women [20, 27–29]. Lee et al. (1998) elaborated that the low prevalence rate could be related to the protective effect of peiyue support preventing the occurrence of PND in early puerperium and that the prevalence rate might be higher if a longer follow up period was adopted. In the present study, the PND prevalence of 15.7% at 2 months after delivery was more comparable with epidemiological studies of the non-Chinese populations that 10 to 15% of recently delivered women were affected by postnatal depression [27–29]. Postnatal depression can impose considerable family vulnerability and distress as well as tension within a marriage [8, 30]. In its severe form, PND can eventually end up with suicide and infanticide. Because of its high prevalence, potential adverse consequences, and treatment availability, the early identification and management of PND is of imminent importance for the health of pregnant women and their families. Researchers investigating postnatal depression in the Chinese populations opined that Chinese women tend to keep their feelings and might choose to keep silent instead of taking the initiative to admit that they have problems so their depressive symptoms are under-reported [3, 31]. Therefore, the active screening and identification of PND by healthcare professionals are particularly essential for the Chinese populations.
There are screening programmes for depression of women during the postnatal period in different places. In Hong Kong, the implementation of the CCDS since 2005 aims to serve the purpose of identifying PND early at MCHCs, where postnatal Chinese women are screened for postnatal depression with the Chinese version of the EPDS [15–19]. Those screened positive are assessed by psychiatric nurses at MCHCs and those deemed in need of further psychiatric management are referred to psychiatrists. To identify postnatal depression early, apart from implementing a screening programme with the use of EPDS for postnatal women, it is important to determine risk factors for postnatal depression so that Chinese women with these risk factors are monitored more closely [4, 32].
Studies for exploring the antenatal risk factors for postnatal depression in the Chinese populations are relatively scarce, not up to date, and without using standardized diagnostic schedules and the most recent large scale one was by Lee et al. 2004 [9, 14]. With the implementation of the CCDS for the early identification and management of PND in primary healthcare settings since 2005, it is the time to re-assess the risk factors for postnatal depression for Chinese women at the community level (i.e. at MCHCs where a significant proportion of women receive antenatal care). The results of this study serve as the blueprint for the further modifications of the service delivery model of perinatal psychiatric services for Chinese women.
Risk factors for postnatal depression
In the present study, marital dissatisfaction (Relative Risk = 8.27), dissatisfied relationship with mother-in-law (Relative Risk = 3.93), antenatal depressive symptomatology (Relative Risk = 3.90), and anxiety-prone personality (Relative Risk = 2.14) predicted PND independently. Marital dissatisfaction has been consistently found to be an important determinant of postnatal depression [9, 11, 12]. Dissatisfied relationship with mother-in-law is a salient risk factor for postnatal depression in the Chinese populations [9, 14]. In the traditional Chinese culture, after marriage, a woman would be named under her husband's surname and move to live with her husband's family. Moreover, the woman would become the "subordinate daughter" of her mother-in-law and be responsible to take care of her husband's family members. Under the role of a "subordinate daughter", the woman is supposed to respect and obey the opinions and advices from her mother-in-law in different aspects of her life including the ways to take care of the family and the newborn child [9, 14, 31]. Overt and covert conflicts would then emerge if the woman has different views with her mother-in-law and these conflicts can impose significant distress in the woman. Despite that Hong Kong has been developed as a modern city in the recent decades and that many women in Hong Kong now would not live with her mother-in-law after marriage, the traditional Chinese beliefs that a woman would be "subordinate" to her mother-in-law still prevail in some Chinese families. After the birth of a child, a woman would have increased contact with her mother-in-law if her mother-in-law provides peiyue support or if her mother-in-law pays visits to the newborn child at the woman's home. Because of the increased contact, conflicts on the ways of childcare between the woman and her mother-in-law become prominent and the adverse effects of these conflicts exacerbate if the woman could not gain the support from her husband. It is therefore not surprising that dissatisfied marital relationship and dissatisfied relationship with mother-in-law contribute significantly for the development of PND in Chinese women.
In the study by Lee et al. (2004) on Chinese women, conflicts with mother-in-law, marital dissatisfaction, past depression and antenatal depressive symptomatology were found to be independent antenatal risk factors for postnatal depression . The results of the present study replicated some of the findings of Lee et al. in that marital dissatisfaction, dissatisfied relationship with mother-in-law and antenatal depressive symptomatology independently predicted PND [9, 14]. Though past history of depression was associated with an increased risk for PND by univariate analysis, it was not an independent risk factor for PND in multivariate analysis in the present study. This negative finding might be due to the relatively small proportion (8.1%) of women suffered from a past history of depression in the present study. Instead, anxiety-prone personality was found to have predicted PND independently in the present study in which 62.7% of women with postnatal depression had anxiety-prone personality. The result echo with studies in the non-perinatal contexts that anxiety-prone personality is associated with depression [33–35]. The findings of the present study point to the importance of assessing antenatal depressive symptomatology and close monitoring of Chinese women with significant antenatal depressive symptomatology (e.g. those with antenatal EPDS score > 9) during the postnatal period for PND. Chinese women with anxiety-prone personality and relationship problems with husband and or mother-in-law also warrant close follow up. Moreover, antenatal interventions aiming at reducing these risk factors may serve to lower the chance of developing PND.
In Lee et al. study (2000), spouse dissatisfaction with the female gender of the baby increased the risk for PND . In the traditional Chinese culture, a boy was more treasured than a girl as a boy signifies the promulgation of the family to the next and subsequent generations. However, the present study did not show that spouse dissatisfaction with the gender of the baby was a significant risk factor for PND. On the other hand, we found that quite a large number of participants and their spouse preferred to have a girl rather than a boy despite that they were not dissatisfied with the male gender of the baby. They opined that a daughter might be more obedient and attached to the family and that a daughter might be more caring for her parents when they get old. This phenomenon may reflect a change of values in the Chinese society in recent years that instead of the gender, the character and relationship of the child with the family are considered by parents as the most preferred attributes of the child. It would be important to evaluate in future studies whether this change in cultural preference of offspring gender may also exist in other Chinese communities, especially in the Mainland China with the implementation of its one-child policy.
The results of the present study are in consonance with the results of Lee et al. (2004) in that the presence of peiyue lowered the risk for PND but did not contribute to predict PND independently in multivariate analysis . Peiyue is a Chinese postpartum custom of mandated family support during which recently delivered women are regarded as vulnerable and are exempted from their usual household duties in the month after delivery with the continual presence of a designated elder female kin, most commonly the women's mother or mother-in-law . Lee et al. (2004) pointed out that if the mother-in-law was the peiyue support and the new mother did not get along well with her mother-in-law, the in-law tension could offset the potential benefit of the peiyue arrangement. In this study, the majority of women had peiyue support by their mother (39.6%) followed by their mother-in-law (25.8%) and 4.2% had support by peiyue maid. Some participants indicated that during the peiyue period they felt tired in dealing with their relationship problems and conflicts with their mother-in-law over child care and these conflicts made the women become distressed. On the other hand, in the present study, about half of those having peiyue maids as the peiyue support mentioned that the peiyue maids were not very helpful and skilful and that being with a person that they knew little before delivery made them feel uneasy. Peiyue maid is a relatively new occupation that has emerged in the recent years in the Chinese populations for the support of women during the peiyue period. The peiyue maid is trained to take care of the new mother, cook for her and assist her in child care. Therefore, we believe that the quality of peiyue support was much more important than the presence or absence of peiyue support. Moreover, the training programmes for peiyue maids may need to be enhanced.
Persistent wound (episiotomy wound or Caesarean section wound) pain for more than 2 weeks was found to be a significant risk factor in univariate analysis in this study despite that it did not predict PND independently. The relationships between pain and depression have been discussed extensively in the literature [36–38]. As compared with people without depression, people with depression reported more pain symptoms and depression and pain may share common pathogenic pathways with the involvement of serotonin. Moreover, the presence of pain may predict worse treatment response for depression . Therefore, postnatal Chinese women with the presence of persistent episiotomy or Caesarean section wound pain need adequate wound care and pain control.
The findings in the present study support the importance of assessing antenatal depressive symptomatology and monitoring Chinese women with significant antenatal depressive symptoms (e.g. those with antenatal EPDS score > 9) closely during the antenatal and postnatal period for depression. In addition, healthcare professionals need to pay particular attention and closely follow Chinese women with anxiety-prone personality, marital dissatisfaction, and dissatisfied relationship with mother-in-law during the antenatal and postnatal period in order to detect PND early.
The results of this study serve as a basis for the further modifications of the service delivery model of the perinatal psychiatric services for Chinese women in Hong Kong. Apart from the screening of PND in primary healthcare settings in the community, the assessments of independent risk factors for PND should also be performed on pregnant Chinese women. With a closer and more frequent monitoring of pregnant women with the independent risk factors found in this study, PND might be identified and managed even earlier. Moreover, the incorporation of programmes and interventions aiming to reduce the impact of these risk factors on the women and their family may help to minimize the chance of the subsequent development of PND.