Race, psychiatric history, and adverse life events have all been independently associated with postpartum depression (PPD). However, the role these play together in Black and Latina women remains inadequately studied. Therefore, we performed a case–control study of PPD, including comprehensive assessments of symptoms and biomarkers, while examining the effects of genetic ancestry.

We recruited our sample (549 cases, 968 controls) at 6 weeks postpartum from obstetrical clinics in North Carolina. PPD status was determined using the MINI-plus. Psychiatric history was extracted from medical records. Participants were administered self-report instruments to assess depression (Edinburgh Postnatal Depression Scale) and adverse life events. Levels of estradiol, progesterone, brain-derived neurotrophic factor, oxytocin, and allopregnanalone were assayed. Principal components from genotype data were used to estimate genetic ancestry and logistic regression was used to identify predictors of PPD.

This population was racially diverse (68% Black, 13% Latina, 18% European). Genetic ancestry was not a predictor of PPD. Case status was predicted by a history of major depression (p = 4.01E-14), lifetime anxiety disorder diagnosis (p = 1.25E-34), and adverse life events (p = 6.06E-06). There were no significant differences between groups in any hormones or neurosteroids.

Psychiatric history and multiple exposures to adverse life events were significant predictors of PPD in a population of minority and low-income women. Genetic ancestry and hormone levels were not predictive of case status. Increased genetic vulnerability in conjunction with risk factors may predict the onset of PPD, whereas genetic ancestry does not appear predictive.

Childbirth is a potent trigger for the onset of psychiatric illness in women including postpartum depression (PPD) and postpartum psychosis (PP). Medical complications occurring during pregnancy and/or childbirth have been linked to postpartum psychiatric illness and sociodemographic factors. We evaluated if pregnancy and obstetrical predictors have similar effects on different types of postpartum psychiatric disorders.

A population-based cohort study using Danish registers was conducted in 392 458 primiparous women with a singleton delivery between 1995 and 2012 and no previous psychiatric history. The main outcome was first-onset postpartum psychiatric episodes. Incidence rate ratios (IRRs) were calculated for any psychiatric contact in four quarters for the first year postpartum.

PPD and postpartum acute stress reactions were associated with pregnancy and obstetrical complications. For PPD, hyperemesis gravidarum [IRR 2.69, 95% confidence interval (CI) 1.93–3.73], gestational hypertension (IRR 1.84, 95% CI 1.33–2.55), pre-eclampsia (IRR 1.45, 95% CI 1.14–1.84) and Cesarean section (C-section) (IRR 1.32, 95% CI 1.13–1.53) were associated with increased risk. For postpartum acute stress, hyperemesis gravidarum (IRR 1.93, 95% CI 1.38–2.71), preterm birth (IRR 1.51, 95% CI 1.30–1.75), gestational diabetes (IRR 1.42, 95% CI 1.03–1.97) and C-section (IRR 1.36, 95% CI 1.20–1.55) were associated with increased risk. In contrast, risk of PP was not associated with pregnancy or obstetrical complications.

Pregnancy and obstetrical complications can increase the risk for PPD and acute stress reactions but not PP. Identification of postpartum women requiring secondary care is needed to develop targeted approaches for screening and treatment. Future work should focus on understanding the contributions of psychological stressors and underlying biology on the development of postpartum psychiatric illness.

Universal screening for postpartum depression is recommended in many countries. Knowledge of whether the disclosure of depressive symptoms in the postpartum period differs across cultures could improve detection and provide new insights into the pathogenesis. Moreover, it is a necessary step to evaluate the universal use of screening instruments in research and clinical practice. In the current study we sought to assess whether the Edinburgh Postnatal Depression Scale (EPDS), the most widely used screening tool for postpartum depression, measures the same underlying construct across cultural groups in a large international dataset.

Ordinal regression and measurement invariance were used to explore the association between culture, operationalized as education, ethnicity/race and continent, and endorsement of depressive symptoms using the EPDS on 8209 new mothers from Europe and the USA.

Education, but not ethnicity/race, influenced the reporting of postpartum depression [difference between robust comparative fit indexes (∆*CFI) < 0.01]. The structure of EPDS responses significantly differed between Europe and the USA (∆*CFI > 0.01), but not between European countries (∆*CFI < 0.01).

Investigators and clinicians should be aware of the potential differences in expression of phenotype of postpartum depression that women of different educational backgrounds may manifest. The increasing cultural heterogeneity of societies together with the tendency towards globalization requires a culturally sensitive approach to patients, research and policies, that takes into account, beyond rhetoric, the context of a person's experiences and the context in which the research is conducted.

Recent evidence suggests that postpartum psychiatric episodes may share similar etiological mechanisms with immune-related disorders. Pre-eclampsia is one of the most prevalent immune-related disorders of pregnancy. Multiple clinical features are shared between pre-eclampsia and postpartum psychiatric disorders, most prominently a strong link to first pregnancies. Therefore, we aimed to study if pre-eclampsia is a risk factor for first-onset postpartum psychiatric episodes.

We conducted a cohort study using the Danish population registry, with a total of 400 717 primiparous women with a singleton delivery between 1995 and 2011. First-lifetime childbirth was the main exposure variable and the outcome of interest was first-onset postpartum psychiatric episodes. The main outcome measures were monthly incidence rate ratios (IRRs), with the period 11–12 months after birth as the reference category. Adjustments were made for age, calendar period, reproductive history, and perinatal maternal health including somatic and obstetric co-morbidity.

Primiparous women were at particularly high risk of first-onset psychiatric episodes during the first month postpartum [IRR 2.93, 95% confidence interval (CI) 2.53–3.40] and pre-eclampsia added to that risk (IRR 4.21, 95% CI 2.89–6.13). Having both pre-eclampsia and a somatic co-morbidity resulted in the highest risk of psychiatric episodes during the 3-month period after childbirth (IRR 4.81, 95% CI 2.72–8.50).

We confirmed an association between pre-eclampsia and postpartum psychiatric episodes. The possible explanations for this association, which are not mutually exclusive, include the psychological impact of a serious medical condition such as pre-eclampsia and the neurobiological impact of pre-eclampsia-related vascular pathology and inflammation.