Article Text
PDF
Abstract
Objectives To assess the impact of prenatal and postnatal family support on the association between infant sex and postpartum depression (PPD).
Design Prospective cohort study.
Setting Pregnant women seen at Hunan Maternal and Infant Hospital, the First Affiliated and the Third Affiliated Hospitals of the Central South University in Changsha, Hunan, People's Republic of China from February to September 2007.
Participants 534 Pregnant women who were consecutively recruited from the participating hospital during their prenatal visits at 30–32 weeks of gestation and who completed the 2 weeks postpartum survey, with no recorded major psychiatric disorders and obstetric and/or pregnancy complications.
Main outcome measure PPD, which was defined as a score of 13 or higher of the Edinburgh Postnatal Depression Scale.
Results Postnatal family support scores were much lower in women who gave birth to a female infant, and the OR of PPD was 3.67 (95% CI 2.31 to 5.84) for them as compared to women who gave birth to a male infant. After adjusting by postnatal support from all family members, husband and parents, the ORs of PPD for women who gave birth to a female infant decreased to 2.06 (95% CI 1.20 to 3.53), 2.89 (95% CI 1.76 to 4.77) and 2.20 (95% CI 1.28 to 3.77), respectively.
Discussion Increased risk of PPD in Chinese women who gave birth to a female infant can be explained to large extent by inadequate or poor postpartum support from family members, particularly husband and parents.
- Postpartum depression
- family support
- infant sex
- Chinese
- depression
- sex inequalities
- perinatal epidemiology
- pregnancy
- social support
Statistics from Altmetric.com
- Postpartum depression
- family support
- infant sex
- Chinese
- depression
- sex inequalities
- perinatal epidemiology
- pregnancy
- social support
Postpartum depression (PPD), affecting 10–20% of pregnant women worldwide, is a subtype of major depression with onset within 6 months after childbirth.1–6 PPD is a major public health problem that impacts on a woman's health and wellbeing as well as the infant's.7–10 Furthermore, PPD may have lasting effects on women's mental health.11
Epidemiologic studies have identified several risk factors such as a personal or family history of a major depression; perinatal stressors; psychosocial stressors; demographic, socio-economic and socio-cultural factors and lack of social support.4 6 9 12
Our previous study in a cohort of Chinese women found that the rate of PPD in women who gave birth to a female infant was 24.6%, while the rate in women who gave birth to a male infant was 12.2%, with an OR of 2.89 after adjusting for potential confounding by maternal age, education level, family income, living condition, gravidity, number of prenatal care visits and mode of delivery.6 These findings echo the results of studies from India13 and China.14 15 However, studies conducted in Western societies failed to find an association between infant sex and PPD.12
In the family-centred and male-preferred Chinese society, inadequate or poor postpartum support from family members in women who give birth to a female infant may cause, to a large extent, the increased risk of PPD. This study aims to explore whether lack of family support during the postpartum period mediates the association between PPD and birth of a female infant.
Materials and methods
Approval from the Research Ethics Board of Central South University was obtained before the commencement of the study. Study participants were pregnant women presented at Hunan Maternal and Infant Hospital, the First Affiliated and the Third Affiliated Hospitals of the Central South University in Changsha, Hunan, People's Republic of China from February to September 2007, during their prenatal visits at 30–32 weeks of gestation. Eligible study participants were married primiparous women from 20 to 45 years of age who came to the participating hospitals for prenatal care and childbirth and planned to stay in Changsha during the postpartum period. Women were excluded if they presented with multi-fetal pregnancy, a current or lifetime history of bipolar disorder, schizophrenia or other psychotic illnesses, a major chronic disease or developed obstetric and pregnancy complication (severe preeclampsia/eclampsia, placenta previa, placental abruption, major postpartum infection, stillbirth, major birth defects or birth weight <1500 g) as recorded in medical charts.
All participants were provided informed consent. Research nurses collected relevant clinical and epidemiological data from the study participants using structured interviews. Social support level was assessed using the Social Support Rating Scale (SSRS)16 at 30–32 weeks of gestation (prenatal support) and again at 2 weeks postpartum (postnatal support). The SSRS, a 10-item scale, for which the English version has been reported,17 is based on the unique environmental and cultural conditions in China. This scale consists of 10 items, with three dimensions: subjective support (four items), objective support (three items), and support availability (three items). Subjective support reflects an individual's level of satisfaction of being respected, supported and understood by key individuals in their interpersonal environment. Objective support reflects the degree of practical support the social network is able to provide (including monetary or other living necessities). Support availability refers to the availability and effectiveness of social supports for dealing with a life event (eg, childbirth). Details of this scale can be found in our earlier report.17 The family support item of the scale includes support from husband or wife, parents (including parents-in-law), sisters/brothers (including sisters/brothers-in-law), children and other family members, with a score of 1=none, 2=rarely, 3=some support/care, 4=strong support/care. This scale has been widely used in the general population for individuals 14 years of age or older in China and has well-established validity and reproducibility.16 For pregnant women, however, a few modifications may be needed (eg, support from children is not applicable in our study population because most of the women are new mothers).
The Chinese version of the Edinburgh Postnatal Depression Scale (EPDS),18 a 10-item self-report instrument, was used to assess PPD at 2 weeks postpartum. The cut-off point for PPD is 13 or higher. It has well-demonstrated reliability and validity in identifying depression, even though the EPDS is not a diagnosis of PPD,19 and it has been widely applied in both research and clinical settings.19 The sensitivity (0.82) and specificity (0.86) of the Chinese version of the EPDS is comparable to the original scale.20
The distribution of demographic and perinatal characteristics and prenatal and postnatal family support levels (from all family members and from different categories of family members) were compared between women who gave birth to a female infant and those who gave birth to a male infant. The association between fetal sex and PPD were examined by logistic regression in the following steps: (1) entered only infant sex as the independent variable (crude estimation); (2) adjusted for socio-demographic factor (household income); (3) adjusted for socio-demographic and obstetric factors (number of abortion and mode of delivery); (4) adjusted for socio-demographic and obstetric factors and prenatal family support level and (5) adjusted for socio-demographic and obstetric factors and postnatal family support level. A combination of preliminary analysis of our data as well as biological rationale was used in the selection of the confounding variables to be entered into the multiple logistic regression model. For example, although lack of accompanied delivery and early contacts was associated with PPD, they were part of the social support network. To avoid over-adjustment and a potential collinearity problem, we did not put these two variables into the regression model. To assess the relative importance of support from different members of the family, support from all family members and from individual members such as husband, parents, brothers/sisters, etc. were entered into the regression models consecutively. The same set of socio-demographic and obstetric factors described above were entered into the regression models. All analyses were performed using SPSS V. 13.0 (SPSS, Chicago).
Results
The research nurses approached 666 women and 634 women agreed and completed the prenatal survey. At 2 weeks postpartum survey, 24 women withdrew, 25 were lost to follow-up and 10 had missing information in >20% of the variables. A further 41 women were excluded because of recorded major psychiatric disorders and obstetric and/or pregnancy complications, leaving 534 (84.2% of the consented women at 30–32 weeks of gestation) for analysis. The socio-demographic characteristics between women who participated in the postpartum follow-up and those who did not were similar (data available upon request).
The baseline characteristics of the two study groups (male vs female infants) were similar, although women who gave birth to a female infant had a slightly higher household income, more prenatal care visits and higher caesarean delivery rate (table 1). One hundred and three women (19.3%) were found to have PPD. The rate of PPD was 30.1% in women who gave birth to a female infant and 10.5% in those who gave birth to a male infant (table 1).
Comparison of demographic and obstetric characteristic between women gave a birth of female infant and those who gave a birth of male infant, Changsha, China, 2007
Table 2 shows that there was no difference in family support score, either from all family members or from specific categories of family members such as husband, parents, sisters/brothers and other family members measured during pregnancy between women who gave birth to a female infant and those who gave birth to a male infant. In contrast, postnatal family support scores, either from all family members or from specific categories of family members, were significantly lower among women who gave birth to a female infant.
Comparison of family support levels (score in mean (SD) measured prenatal and postnatal between women who gave a birth to female infant and those who gave a birth to male infant, Changsha, China, 2007
Table 3 displays the crude and adjusted ORs of PPD. The OR of PPD for women who gave birth to a female infant as compared with those women who gave birth to a male infant was 3.67 (95% CI 2.31 to 5.84). Adjustment for prenatal family support did not change the OR of PPD for women who gave birth to a female infant as compared with those women who gave birth to a male infant. In contrary, ORs of PPD for women who gave birth to a female infant decreased to 2.06 (95% CI 1.20 to 3.53), 2.89 (95% CI 1.76 to 4.77) and 2.20 (95% CI 1.28 to 3.77), respectively, after adjustment for postnatal support from all family members, husband and parents.
Association between fetal sex and postpartum depression, Changsha, China, 2007
Discussion
Our study, based on a cohort of Chinese women, found that the risk of PPD in women who gave birth to a female infant was increased as compared to those women who gave birth to a male infant, and inadequate or poor support from family members explain in large part the increased risk of PPD in these women. Moreover, our study found that the inadequate or poor support from key family members, such as husband and parents immediately after childbirth, is the most important factor in explaining the female infant sex associated increased risk of PPD.
The occurrence of PPD in our study sample was about 19%, which is consistent with previous studies in China.6 14 15 21 22 The distribution of demographic and perinatal characteristics in our study sample, such as exceptionally high marriage rates and caesarean delivery rate, is consistent with the general obstetric populations in recent Chinese studies as well.6 23 Our study confirmed the findings of earlier studies in China that women who gave birth to a female infant were at increased risk of developing PPD.6 14 15
We did not find major differences in baseline characteristics between the two study groups. As a result, other factors may be the reasons for the increased risk of PPD in women with a female infant. In our data, parents did not know the sex of the fetus before delivery. Since 2002, prenatal sex identification and sex-selective abortion are prohibited in China, and physicians who do not comply with these policies will be charged under the criminal law (http://www.unescap.org/esid/psis/population/database/poplaws/law_china/ch_record006.htm) and risk suspension of medical licensure. We speculate that the negative reaction of family members towards the birth of a female baby, which may subsequently affect their support of the mother, may be a potential risk factor for PPD within certain cultural groups.12 In the family-centred and male-preferred Chinese society, family support may play a critical role in the increased risk of PPD in women who give birth to a female infant, especially so because of the one-family one-child policy that was in effect at the time of this study. The levels of family support measured during pregnancy were similar between women who carry a female fetus and those who carry a male fetus. This is not surprising given that fetal sex is unknown at that time. The levels of postnatal family support were substantially lower in women who gave birth to a female infant. This also is not a surprise, as the infant sex became known at this time. The association between infant sex and PPD remained the same after adjustment for socio-demographic and obstetric factors and prenatal family support but substantially decreased after adjustment for postnatal family support, suggesting that lack of social support after childbirth may mediate the relationship between PPD and giving birth to a female infant.
Deteriorating marital/partner relationship after the birth of a girl baby may be another explanation.5 Preference for boys to girls is a widely recognised phenomenon in China. There are several potential explanations for this phenomenon. Because of the lack of social security system in China, parents rely on their sons for economic support when they become old. Women usually live in their husband's home after marriage and cannot provide the same level of support to their own parents as men can. Moreover, family names are considered the important symbol of the family, and these names are usually followed the husband's family name. The effect of male preference may be one of the most important risk factors in the mother's being depressed in a society that values boys more highly.
Limitations of our study should be taken into consideration in the interpretation of the results. Selection bias might be possible during the recruitment process (ie, patients at either end of the emotional spectrum might not be inclined to participate). We do not know how representative of the general population the women in this study were. This may affect the generalisability of the study. However, our finding of increased risk of PPD in women who gave birth to a female infant than those women who gave birth to a male infant has been repeatedly observed in male dominant society such as Indian13 and China,14 15 which lends validity to our study. The measurement of postnatal family support was conducted at the same time with PPD, and the measurements of these two may interact with each other and, therefore, bias the results. The EP DS is a screening measure, not a diagnostic tool for depression. We have not been able to consider some important factors such as mothers' degree of satisfaction with the baby including sex. EPDS assessment or other depression assessment, which would have been useful to monitor changes, was not conducted during pregnancy. We will consider these useful design issues in future studies.
Despite these limitations, the results of our prospective cohort study were consistent with previous findings on the association between infant sex and PPD in Chinese women. Furthermore, our study found that the lack of family support after childbirth, especially those from the husband and parents, is likely a main reason for the increased risk of PPD in Chinese women who gave birth to a female infant as compared to those who gave birth to a male infant. This finding is important in terms of providing additional evidence to support the theory that family support is a predictor of PPD and may have important practical implication as well. For example, because of the limited resources, to maximise cost-effectiveness, interventions aiming at reducing the risk of PPD for women carrying a female fetus should focus on postpartum period, with key family members such as husband and parents being involved. On the other hand, because family support cannot explain all of the female infant sex associated increase in the risk of PPD, intervention from other sources such as professions could play a role here as well.
What is already known on this subject?
In some male-dominated societies/cultures such as those found in India and China, women who gave birth to a female infant are at increased risk of PPD than those women who gave birth to a male infant.
What this study adds
Inadequate or poor support from family members, particularly from the husband and parents and immediately after childbirth, explain in large part the increased risk of PPD in women who gave birth to a female infant than those women who gave birth to a male infant.
Acknowledgments
Dr Xie is an Ontario University of Ottawa Vision 2010 Postdoctoral Fellow. Dr Wen is a recipient of the Ontario Women's Health Council, Institute of Gender and Health of CIHR Mid Career Award. Dr Walker is a new investigator of CIHR. This study was supported by grants by Hunan Provincial Natural Science Foundation of China (06JJ4055), Scientific Research Fund of Hunan Provincial Education Department (06C072) and Hunan Ministry of Science and Technology (06FJ4103). We thank pregnant women and staff of the participating hospitals in Changsha, China for their support.
References
Footnotes
Funding Other funders: Canadian Institutes for Health Research and Chinese funding agencies.
Competing interests None.
Ethics approval This study was conducted with the approval of the Central South University in China.
Provenance and peer review Not commissioned; externally peer reviewed.