Antenatal depression: an examination of prevalence and its associated factors among pregnant women attending Harare polyclinics

Maternal and child health remains a worldwide health priority. Although the global community has worked strenuously to reduce physical causes of maternal and child mortality and morbidity [1], other contributing factors, such as maternal mental health, have received less attention [2‐4]. Unfortunately, adverse maternal mental health increases the risks of obstetric and child outcomes such as low birth weight, prematurity and increased risks of assisted births [5‐8], and lifelong maternal mental health issues [9]. For example, common mental health disorders in the perinatal period, particularly depression, are highly prevalent [10].

Global prevalence estimates of antenatal depression vary across regions [8]. The burden of antenatal depression is generally higher in low- and middle-income countries (LMICs) [10, 11]. For instance, the prevalence of maternal depression in women from Sub-Saharan Africa ranges from 20 to 49% [5, 12‐23]. These prevalence variations can be explained by several reasons. Firstly, the population studied can explain these differences. Studies investigating HIV-positive, pregnant women reported higher prevalence of antenatal depression [20‐22]; HIV infection typically increases the risk of depression up to four times [24, 25]. Secondly, pregnancy stage influences prevalence estimates; depression occurrence is trimester-dependent with the burden being greater in the third trimester [13, 26]. Thirdly, tools used to evaluate depression can also explain maternal depression disparities [27]. For instance, most studies in Southern Africa have either used generic depression screening tools [28] or postnatal depression screening tools [29] in measuring antenatal depression which is a potential methodological pitfall. Further, most screening tools are self-report outcome measures which may lead to higher prevalence estimates [10, 27]. On the contrary, diagnostic tools such as the Structured Clinical Interview for Diagnostic and Statistical Manual 4th edition (SCID-IV) [30] which offer a definitive depression diagnosis, are infrequently used. There is only one study in Southern Africa that used a diagnostic tool [17]. Although the Malawian study used a diagnostic tool, the study outcomes may have limited external validity [17]. Structured interviews were carried out by non-mental health practitioners and selection bias was highly probable since participants were recruited using convenience sampling method [17]. There is, therefore, need for robust methodologies in estimating the burden of antenatal depression in low-resource settings. Accordingly, we set to estimate the prevalence of antenatal depression among pregnant women attending Harare polyclinics using the Structured Clinical Interview for DSM-IV (SCID-IV), a diagnostic tool. We also explored potential factors associated with antenatal depression. Understanding the burden of antenatal depression will aid in identifying pregnant women at risk and intervene appropriately thereby reducing its negative effects.

The aim of this study was to examine the prevalence and associated factors of antenatal depression among pregnant women in Harare, Zimbabwe. To our knowledge, this is the first study in Zimbabwe looking at antenatal depression in all pregnant women regardless of HIV status. The prevalence of antenatal depression in our study is high i.e. one in four pregnant women were depressed. Salient predictors to antenatal depression were interpersonal in nature: being married or in an informal, steady relationship were protective factors, and having experienced intimate partner violence or a negative life event were risk factors.

The high prevalence rate in this study is comparable to other LMICs [12, 13, 16, 17]. In South Africa, for example, the prevalence of antenatal depression ranges from 20 to 49% [19, 21, 23, 38]. A recent local/Zimbabwean study among HIV-positive pregnant women [22] also showed a higher prevalence of antenatal depression (39.4%). This is unsurprising as given the high depression comorbidity in people living with HIV [24]. Nevertheless, in the aforementioned study, Nyamukoho et al. [22], used a screening tool, the Edinburgh Postnatal Depression Scale (EPDS), to measure depression, instead of a diagnostic tool as used in our study which may explain discrepancies with the current study. Previous studies suggest that depression screening tools overtly yield higher prevalence rates than diagnostic tools [27]. Prevalence rates obtained when using diagnostic tools are more reflective of the burden of antenatal depression since diagnostic tools are more definitive in their diagnosis [27]. Further, the EPDS has been previously validated among Zimbabwean postnatal women only [32], it is not validated among pregnant women in our setting. This may, therefore, account for differences in antenatal depression as revealed in the current study.

Factors associated with antenatal depression, such as intimate partner violence (IPV), experiencing a negative life event, and marital status, are relational. This is consistent with other regional studies [12‐23]. In Zimbabwe, recent studies have also shown that intimate partner violence is a risk factor for depression in the perinatal period [22, 39]. Unlike other studies in LMICs [5, 12, 13, 17, 18, 21, 40], we did not find any significant associations of antenatal depression with HIV, maternal age, educational level, history of obstetric complications, social support and gravidity. This may be due to methodological differences.

The results of our study highlight the complexity of marital relationships. Being married/cohabitating had a positive effect on maternal mental health, yet intimate partner violence, which is highly prevalent in marriages [39, 41], was negatively associated with antenatal depression. This complexity, yet an important finding, needs to be understood better when thinking of interventions for antenatal depression. Future qualitative studies maybe warranted to explore this phenomenon further. More importantly, it would be beneficial to look at interventions that not only target the affected women but the whole family. Although there has been repeated calls for male involvement in maternal and child health care [42], uptake remains very low mainly due to the traditional beliefs that maternity issues are females’ expertise [43‐45]. Involving male partners in prevention of antenatal depression may potentially play a crucial role since they are at the core of the factors associated with depression as shown in our study.

Given the high rates of antenatal depression and evidence that it has consequences in the post-natal period for both the mother and infant, it is important that culturally sensitive interventions to address these risk factors are available. In Zimbabwe, one intervention, The Friendship Bench, which uses problem solving therapy, has been shown to alleviate depression in the general population [36]. This intervention is currently being rolled out by the Ministry of Health and Child Care in primary care settings. The current scale-up of the Friendship Bench offers a unique opportunity to adapt it so that the intervention tackles the associated factors of antenatal depression seen here.

Our study outcomes need to be interpreted with caution due to some methodological limitations. Social desirability bias is highly likely since the interviews were face-to-face. This may translate to an underestimation of the prevalence of antenatal depression. Additionally, this study was only carried out in urban areas; as such, its generalizability to rural settings may not be guaranteed. Prevalence of antenatal depression varies across trimesters. It would be important to examine depression across trimesters; this study only reports depression across the gestational period. This study also used a diagnostic tool that can only be administered by trained mental health professionals, this may not be practical in our settings where we lack the trained manpower. Despite these limitations, the study adds to the already existing body of knowledge on the burden of antenatal depression. It also helps to inform policy makers on the importance of screening for depression in pregnancy to prevent its negative effects not only on the mother but on the baby as well.

The prevalence of antenatal depression among pregnant women attending antenatal clinics in Harare is high: one in four pregnant is depressed. Being married/cohabitating was a protective factor against antenatal depression, and having experienced intimate partner violence or a negative life event were risk factors of antenatal depression.

Most women are likely to seek health care services during pregnancy hence the antenatal period offers a great opportunity to diagnose and treat antenatal depression. It is important to screen for depression during pregnancy and manage it since it is prevalent, and its associated factors are mostly relational.