Postpartum depression and postpartum post-traumatic stress disorder: prevalence and associated factors

This was a cross-sectional, descriptive study.

Ethical approval for the study was obtain from the hospital Ethics Committee. Researchers approached potential participants and gave a brief introduction of the study (research purpose, potential impact, and participants’ rights). Women were informed that their participation was entirely voluntary, and whether they agreed to participate or not did not impact their treatment. Informed consent was obtained from participants at the beginning of the online questionnaire. All participants were assured that their data would be kept confidential and only accessed by the researcher.

Data were analyzed using the Statistical Package for Social Sciences (SPSS, version 22.0 for Windows). Scores of EPDS and PPQ are presented as the mean (M) and standard deviation (SD). To facilitate statistical analysis and interpretation of the results, the PSSS, EPDS, and PPQ scores were converted into categorical variables. Frequencies and percentages are presented for all categorical variables. A chi-square test and logistic regression analysis were performed to evaluate the association of factors related to PPD and PP-PTSD. Variables were included into the multivariate logistic regression model if the variables had a significant association (P ≤ 0.20) by the χ² test or deemed important enough clinically, despite no statistical significance. All statistics were performed using two-sided tests, and the significance level was set at a P <  0.05.

During the research period, 1200 eligible women were approached, and 1136 of them agreed to participate in the study and completed the questionnaire (94.6% response rate). The characteristics of the participants are shown in Table 1. The mean age of the participants was 30.16 ± 3.91 years. The majority of participants had a bachelor’s degree or above (n = 961 [84.6%]), 2 participants (0.2%) reported smoking cigarettes during pregnancy, 479 participants (42.2%) had only 1 child in the family, and 821 participants (72.3%) were primiparas.

The mean EPDS score was 9.54 ± 4.46 (range = 3–25), and 267 (23.5%) women had PPD symptoms with an EPDS score ≥ 13. Based on univariate analysis (Table 1), there was a significant difference in the prevalence of PPD symptoms among the groups with respect to the household registration location, ethnicity, one child families, sleep quality, social support, newborn’s Apgar score in 1 min, newborn’s incubator admission and PP-PTSD symptoms (P <  0.05) using a chi-square test.

In the multivariate model (Table 2), women with low sleep quality (OR, 3.658; 95% CI, 1.995–6.706) or medium sleep quality (OR, 1.924; 95% CI, 1.314–2.760) were more likely to have PPD symptoms than women with high sleep quality. Compared to women with a low level of social support, medium or high social support reduced the odds of PPD symptoms (OR, 0.128; 95% CI, 0.035–0.465 and OR, 0.030; 95% CI, 0.008–0.108, respectively). Women with a newborn who had incubator admission reported a higher risk of PPD symptoms than women without (OR, 2.109; 95CI, 1.117–3.982). The presence of PP-PTSD symptoms increased the risk of PPD symptoms (OR, 9.170; 95% CI, 4.773–17.617).

The mean PPQ score was 6.30 ± 6.37 (range = 0–45), and 69 (6.1%) women had PP-PTSD symptoms with a PPQ score ≥ 19. Based on univariate analysis (Table 1), there were significant differences in the prevalence of PP-PTSD symptoms among the groups with respect to household registration location, ethnicity, one child families, sleep quality, social support, newborn’s Apgar score in 1 min, and PPD symptoms (P < 0.05) using a chi-square test.

In the multivariate model (Table 3), women of non-Han ethnicity were more likely to experience PP-PTSD symptoms that women of Han ethnicity. Women with pregnancy-induced hypertension had a higher risk of PP-PTSD symptoms than women who did not have pregnancy-induced hypertension (OR, 5.041; 95% CI, 1.724–14.743). Being the only child in the family and having high social support reduced the odds of PP-PTSD symptoms (OR, 0.436; 95% CI, 0.023–0.828 and OR, 0.211; 95% CI, 0.069–0.643, respectively). The presence of PPD symptoms increased the risk of PP-PTSD symptoms (OR, 9.807; 95% CI, 5.071–18.962).

Maternal mental disorders, including PPD, anxiety, and PP-PTSD, are common but often overlooked in China. Due to diversity of the regional economy, culture and policy, and heterogeneity in the prevalence of maternal health disorders has been reported among regions of China [20‐22]. In our study, the prevalence of PPD symptoms was 23.5%, which was within the range of 8–26% reported in a global review article that included 58 articles (N = 37,294 women) [44], but higher than studies reported in other areas of China [20‐22]. This finding suggests that PPD symptoms among women in Shanghai may be high in China and in need of more attention. One explanation is that this study conduct in Shanghai, one of the most economically developed regions in China, the increasing public awareness of maternal mental health, and practice of routine screening PPD may contribute to the increased detection of PPD symptoms. Another possible explanation is that Shanghai has a large amount of transient and floating population. In this study, only 29.5% of the participant are Shanghainese (with local identification). The high mobility of society may weaken the individual’s identity of the residential community and reduce the availability of social support, then results in poor mental health.

We reported a PP-PTSD symptom prevalence of 6.1% among parturients 6–8 weeks postpartum. This finding is similar to that reported by Yildiz et al. [14] (5.8%, 4–6 weeks, 1.4%, 3 months; and 6.8%, 6 months) in a review article that included 28 international studies, but less than the results reported by Radoš et al., [45] (11.8% as measured by the City Birth Trauma Scale). This inconsistency may be explained by the different measures.

It is worth noting that due culture and social norm differences, Chinese often adopt a more conservative attitude toward mental disorders and tend to conceal their psychological discomfort [24]. This fact may contribute to a lower rate of reporting mental disorders in China.

Previous studies have shown that mental health disorders often co-exist and affect each other [2, 24]. Suffering from prior depression leads to a strong vulnerability for developing PP-PTSD, while prior PTSD has been shown to render women vulnerable to PPD [2]. In this study, we also confirm that PP-PTSD is the strongest risk factor for PPD and vice versa. Dekel et al. [2] emphasized that co-existing PPD and PP-PTSD signify a distinct condition and should be deemed as an independent childbirth outcome. Biological studies of non-postpartum samples have shown that compared to depression or PTSD alone, co-morbid depression and PTSD are associated with distinctive biomarkers [46, 47].

Social support was an important protective factor for PPD and PP-PTSD in the current study, which is consistent with previous studies [24, 48]. Being a mother and taking care of a newborn in the early postpartum period can be very challenging, which involves hormonal imbalance, blood loss, pain, and sleep deprivation [10]. Even a full-term delivery with health outcomes may be associated with fear, loss of control, and body integrity [10]. All of these factors result in a greater need of support from family, friends, neighbors, colleagues, and other groups. Without adequate social support, women will be at high risk for mental disorders. Moreover, different aspects of social support are recommended in different contexts. For example, informational and instrumental support may be more in need at 3 weeks postpartum, while social integration may be more in need at 8 weeks postpartum [49].

The association between sleep quality and PPD was confirmed in our study, which is consistent with previous studies [29, 50]. Poor sleep quality has been reported in women from late pregnancy to even 3 years postpartum [50]. Thus, a flexible suite of interventions targeting poor sleep quality may be a good way to solve mental health problems [50].

Our results showed that compared to women of Han ethnicity, women of non-Han ethnicity were more likely to report PP-PTSD symptoms. China, it should be noted, is one of the world’s largest multi-ethnic countries, with 55 ethnic minorities accounting for approximately 8.5% of the overall population [51]. Compared with the Han ethnicity, the non-Han ethnicity (ethnic minorities) is often under greater social and economic pressure and has more difficulties to get advanced medical resources [51]. The health inequality in maternal and child care may contribute to the differences in maternal mental health status.

An interesting finding in the current study was that being the only child in a family was a protective factor for PP-PTSD. The majority of our participants were born under the influence of the one-child policy in China (1978–2015) and approximately one-half of the participants (n = 479 [42.2%]) were the only child in the family [52]. Compared to women with siblings, women who were the only child in the family usually had more parental attention, higher family support, more opportunities for a higher education, and lower economic pressures [52]. This fact may explain the protective role of the one child status and PP-PTSD symptoms. The moderating role of the one child status in direct and indirect relationships between negative life events and PTSD symptoms have been tested in non-postpartum samples [53, 54].

Several factors, such as low education [48], cigarette smoking [48], primiparity [48] and a history of a cesarean section [33, 34] have been reported to be associated with PP-PTSD in some studies, but not confirmed in our study. The reason for this discrepancy might be differences among study populations, regions, study settings, and the measurement tools used. In the study sample, the education level of women was relatively high, with 84.6% having a bachelor’s degree or above and the number of women who reported cigarette abuse was extremely low (2 of 1143). With respect to parity, the results are conflicting. In contrast to previous studies [33, 34], Abedian et al., [55] reported that multiparas had a higher rate and mean score of PP-PTSD than primiparas. This finding may be attributed to lower postpartum social support among multiparas and a higher rate of unplanned pregnancy than primiparas [55]. More quantitative research is needed to further evaluate these associations.

Furthermore, newborn-related factors, only newborn’s incubator admission had been confirmed to be related with women’s PPD symptoms in this study, other factors such as low birth weight, preterm birth, NICU admission, and diagnosis of hyperbilirubinemia showed no association with PPD or PP-PTSD in the current study, which was consistent with a study of 1531 women in Spain with PP-PTSD assessed by the PPQ [33]. A possible explanation is that women with newborn had complications may receive more meticulous care and support from both healthcare providers and family member. It can be assumed that compared with the occurrence of newborn complications itself, how the mothers treat and deal with those events may have a greater impact on her psychology. Qualitative and quantitative research can be carried out to further explore these issues. Moreover, the newborn’s Apgar score in 1 min was correlated with PPD and PP-PTSD symptoms based on univariate analysis but failed to reach statistical significance base on multivariable analysis. The limited number of newborns with mild or severe asphyxia (9/1136) in this study may lead to the contingency of the results.

Although there has been an extensive improvement in prenatal care, psychological care is still largely overlooked. Undetected and untreated mental disorders may lead to a burden on women, their family, the health system, and whole society. Considering the incidence of disease, a routine screening of PPD for all women and PP-PTSD for women at risk during the postpartum period was recommended. Because the comorbidity of mental health disorders existed, for women who exhibited early signs and symptoms of mental health, a more comprehensive and multiple screening of mental disorders is suggested. Obstetricians and midwives can play a crucial role in the initial assessment. For women who are identified to be at risk for PPD or PP-PTSD, prompt referral to multidisciplinary specialists for further assessment and interventions is needed.