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Change in cohabitation status could influence the economic security and well-being of parents and their children. However, literature concerning the association between the duration of perinatal depression (PND) exposure and change in parental cohabitation status is limited. Therefore, this study aimed to assess whether the presence and persistence of maternal PND symptoms are associated with changes in parental cohabitation status up to six years postpartum. Using data from 4,344 persons in the Swedish BASIC and U-BIRTH cohort studies, maternal depressive symptoms were assessed at three time points (during pregnancy, 6 weeks, and 6 months postpartum) using the Edinburgh Postnatal Depression Scale. Cohabitation status was measured at 6 weeks and 6 years postpartum. Logistic regressions estimated odds ratios (ORs) for non-cohabitation associated with the number of PND-positive time points. Mothers with positive screenings at more than one time point for depressive symptoms had higher odds of not cohabiting at both 6 weeks and 6 years postpartum. At 6 years, mothers with depressive symptoms at all three time points had over four times the odds of not cohabiting (OR 4.1, 95% CI 1.7-9.5). However, most associations lost significance after full adjustment for sociodemographic and psychosocial factors, except the association between prolonged PND (3 positive screenings) and non-cohabitation at six years postpartum. Prolonged PND symptoms may increase the risk of long-term parental separation. Although confounding factors reduce the strength of this association, findings underscore the need for extended mental health monitoring and support for perinatal persons.

Early identification of postpartum depression and anxiety is critical for enabling timely preventive interventions. Although antenatal self-report measures are strong and widely used predictors of postpartum mental health outcomes, it remains unclear whether physiological markers such as heart rate variability (HRV) provide incremental predictive value beyond established psychological assessments, particularly when measured at different stages of pregnancy. This study investigated whether HRV indices, measured during early and late pregnancy, before and after a mild cognitive-emotional stressor, contribute incremental predictive information for postpartum depression and anxiety symptoms beyond established psychosocial and health predictors. Ninety-one pregnant women completed psychological assessments and HRV measurements before and after a mild cognitive-emotional stressor in both early and late pregnancy. Postpartum depression and anxiety symptoms were assessed using validated questionnaires. Random Forest models identified several HRV indices - particularly low-frequency/high-frequency ratio and indices reflecting parasympathetic activity- as meaningful predictors of postpartum outcomes, alongside established psychological factors. The models demonstrated high predictive accuracy, and model comparisons indicated that HRV measures provided a modest yet statistically reliable improvement, specifically reflected in reduced mean absolute error for depression and state anxiety. These findings suggest that HRV provides complementary physiological information beyond self-report measures, supporting its potential role in refining postpartum risk prediction - particularly in cases where self-report indicators alone may be ambiguous.

Miscarriage occurs in approximately 15% of all pregnancies, and recent studies have suggested a potential role of the microbiome. A nested case-control study from the Swedish Maternal Microbiome cohort was conducted, including 34 participants who sent at least one vaginal or fecal microbiome sample and questionnaire data before miscarrying (n = 34), and matched controls (n = 105 for regression models, n = 27 for machine learning models). Non-vaccine type HPV (aOR 3.95, 95%CI 1.04-15.06) and vaginal microbiome with community state type (CST) II (aOR 6.52, 95%CI 1.58-26.98) or CST-IVB (aOR 4.18, 95%CI 1.08-16.18) in early pregnancy were associated with an increased risk of miscarriage. Furthermore, we explored six machine learning algorithms using 70% of the cohort for training and 30% for testing, for the prediction of miscarriage using vaginal (AUROC 85%), fecal (AUROC 81%) and questionnaire (AUROC 82%) data separately and combined (AUROC 82%). Our results highlight the urgency of HPV screening and vaccine development for women's reproductive health. Despite limitations, including a small number of miscarriage cases, our results indicate the potential for both vaginal and fecal microbiomes in the prediction of miscarriage.

IMPORTANCE: Paternal psychiatric disorders during the perinatal period can affect the health of the entire family; however, these conditions have often been underrecognized, and little is known about their incidence and timing of onset.

OBJECTIVE: To investigate incidence patterns of new-onset diagnosed psychiatric disorders among men in Sweden before, during, and after a partner's pregnancy.

DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study used linked national register data for all fathers of children born in Sweden between January 1, 2003, and December 31, 2021, with follow-up from 1 year before to 1 year after pregnancy. Data were analyzed from October 1, 2024, to March 31, 2025.

EXPOSURES: The time during pregnancy and 1 year after childbirth (post partum) were considered the risk periods, while 1 year before pregnancy (before conception) was used as the reference period.

MAIN OUTCOMES AND MEASURES: Annual and weekly incidence rates (IRs) of clinical diagnoses of any psychiatric disorder and 9 type-specific disorders were calculated and standardized by age and calendar year. Adjusted Poisson regression analysis was used to further estimate incidence rate ratios (IRRs) of psychiatric disorders during and after pregnancy compared with before conception.

RESULTS: This study included 1 915 722 births from 1 096 198 fathers (mean [SD] age at childbirth, 33.8 [6.2] years) in Sweden. IRs of any diagnosed psychiatric disorder were lower during pregnancy (eg, pregnancy week 1: IR, 5.50 [95% CI, 4.69-6.31] per 1000 person-years) and the early postpartum period (eg, postpartum week 1: IR, 5.19 [95% CI, 4.41-5.97] per 1000 person-years) than in the corresponding preconception weeks (eg, preconception week 1: IR, 7.00 [95% CI, 5.97-8.04] per 1000 person-years); they returned to comparable rates later post partum. This pattern was also observed for IRRs of anxiety, alcohol use, and drug use (ie, the use of nonalcohol, nontobacco psychoactive drugs) disorders. IRRs of depression (eg, postpartum weeks 45-49: IRR, 1.30 [95% CI, 1.12-1.52]) and stress-related disorders (eg, postpartum weeks 45-49: IRR, 1.36 [95% CI, 1.15-1.61]), however, showed a notable 30% increase toward the end of the first postpartum year. In contrast, IRRs of diagnosis of tobacco use disorder, attention-deficit/hyperactivity disorder, bipolar disorder, or psychosis remained relatively stable before, during, and after pregnancy.

CONCLUSIONS AND RELEVANCE: In this nationwide cohort study, fathers in Sweden were less likely to be diagnosed with a psychiatric disorder during a partner's pregnancy and early post partum than before conception, but IRs returned to comparable levels thereafter. These incidence patterns may reflect transient protection and delayed detection during the transition to fatherhood and support the need for paternal mental health surveillance, particularly for increased depression and stress-related disorders in the late postpartum period.

The occurrence of treatment resistance in women with postpartum depression (PPD) and risk factors for treatment resistance remain less studied. This study aimed to determine the rate of treatment resistance and the associated risk factors among women with PPD in a nationwide setting. Here we conducted a nationwide register-based cohort study of 58,618 patients with a first-ever PPD during 2006-2021 in Sweden. Information on demographics, pregnancy characteristics, pre-existing physical and psychiatric conditions and treatment was retrieved from Swedish national registers. The outcome was treatment-resistant PPD (TRPPD) within 1 year following PPD diagnosis. Associations between potential risk factors and TRPPD were assessed using multivariable Poisson regression. Among the 58,618 patients with PPD, 3,522 (6.0%) met the criteria for TRPPD during 1 year after PPD diagnosis. Lower educational level, lower household income, being non-cohabiting, smoking in early pregnancy, delivery by cesarean section, pre-existing physical conditions and pre-existing psychiatric disorders were significantly associated with a higher risk of TRPPD. In addition, patients with two births (versus primiparity) or with a prior premenstrual disorder had a lower risk of TRPPD. Treatment resistance in patients with PPD is common and is notably associated with specific demographic and clinical profiles. These findings may provide grounds for practical risk assessment at PPD diagnosis and highlight the need for personalized management strategies.

Background: Postpartum depression (PPD) is a common peripartum complication with approximately 13-17% of women being affected. About 30-50% continue to have symptoms 12 months postpartum. Earlier studies have examined women's experiences of treatments to evaluate their effectiveness in supporting women's recovery from PPD. Studies implementing a broader qualitative research focus-exploring factors associated with both personal circumstances and the health care system, and their perceived contribution to remission-are currently lacking.

Aim: To identify the factors women with short- and long-term PPD symptoms view as most important for faster remission.

Method: Participants from a Swedish cohort study (Mom2B) with depressive symptoms above the clinical cut-off of 11 on the Edinburg Postnatal Depression Scale early postpartum, were invited to participate in an interview study. Semi-structure interviews were performed online (n = 12) or via telephone (n = 6). The interviews were transcribed and analyzed using Systematic Text Condensation.

Results: Five themes describing factors of importance for recovery from PPD were identified; 1) Others take responsibility; 2) Practical support; 3) Emotional validation; 4) Thresholds and 5) Struggling to prioritize oneself.

Conclusion: Synthesized from the resulting themes, a five-stage recovery process was identified: realization of symptoms, acceptance, recognizing the need for help, knowledge, and receiving help. This study highlights the key factors in PPD recovery from the perspective of affected women, providing insights to inform and improve postpartum care. The results can help staff visualize the process, which makes them better equipped to support the women effectively.

Depression during pregnancy and in the postpartum period have been receiving increasing attention considering the possible complications for the mother and baby if left untreated. Genetic variations in the estrogen receptor genes (ESR) have been implicated in susceptibility to depression. However, only few studies investigated them in perinatal depression (PND) and none on its different trajectories (i.e., patterns of time of onset and persistency of depression). Here, we explored the association of single nucleotide polymorphisms (SNPs) of the ESR1 and ESR2 genes with PND among 2,973 women in Sweden. PND was defined using the Edinburgh Postnatal Depression Scale, the Depression Self-Rating Scale, use of selective serotonin reuptake inhibitor, and/or medical records. PND trajectories were identified as follows: controls (no depression at any point in the perinatal period), antepartum (depression during pregnancy and resolved postpartum), postpartum-onset (no depression during pregnancy with onset after delivery), and persistent (depression throughout the perinatal period). Multivariable logistic regression was performed. Out of 56 SNPs analyzed, one SNP in the ESR1 gene (rs2982712) was nominally significantly associated with PND (OR 0.83, 95% CI 0.71-0.98, p = 0.03) as well as with persistent depression (OR 0.77, 95% CI 0.61-0.98, p = 0.03) in the overdominant model (DD/dd vs. Dd). In addition, we also found two SNPs, namely rs1884051 (OR 0.74, 95% CI 0.56-0.98, p = 0.03) and rs2228480 (OR 0.77, 95% CI 0.60-0.99, p = 0.04) in the ESR1 gene, that were nominally significantly associated with persistent depression only. None of the ESR1 SNPs were associated with antepartum or postpartum-onset depression. None of the ESR2 SNPs, nor any haplotypes, were associated with PND or its trajectories. Our findings suggest a role of ESR1 in PND, especially its persistent trajectory.

Background and Aims

Exposure to prenatal distress is associated with a risk of developing difficult temperament in infants, an indicator for a higher likelihood of later adverse developmental outcomes, including behavioral and mental health problems. The underlying biological mechanisms of this association are still unclear, but many support the idea of fetal programming, which postulates the influence of environmental factors on the fetus during pregnancy. Evidence points to the role of cortisol as a mediator of stress, but the results are inconsistent. In this systematic review and meta-analysis, the association between prenatal distress and difficult infant temperament will be assessed, focusing on cortisol exposure as a possible mediator and including subgroup analyses.

Methods

Literature research will be performed in PubMed, Web of Science, MEDLINE, PSYNDEX, APA PsycArticles, APA PsycInfo, and CINAHL. Inclusion criteria are the availability of (self-) assessment of maternal prenatal distress, maternal prenatal cortisol levels, and (parental) assessment of difficult infant temperament up to the age of 2 years. Screening and selection of peer-reviewed English (or German) articles and assessment of article quality will be done by two independent reviewers, with a third one included in the case of disagreement. Effect sizes will be extracted and subgroup analyses will be performed not only for covariables but also for the methods of assessing prenatal distress, cortisol, and temperament. This protocol follows the PRISMA-P checklist.

Conclusion

This systematic review and meta-analysis will contribute to the ongoing discussion of whether and how cortisol mediates the association between prenatal maternal distress and difficult infant temperament. Identifying sensitive subgroups is an integral part of this study, as results might guide further research to vulnerable population groups.

BACKGROUND: Differences in the gut microbiome between lean and obese individuals, even twins, have been recognized for over a decade. The causative role of the microbiome in obesity is known from both mouse and human studies. In parallel, the gut microbiome has been implicated in the most common complications of pregnancy, including preterm birth, gestational diabetes mellitus, and gestational hypertension. Despite obesity being a well-established risk factor for these complications, the composition of the gut microbiome of obese pregnant individuals has not yet been studied. Here, we have examined the differences in the faecal microbiota between lean (n = 746) and obese (n = 254) pregnant women in Sweden, at two timepoints in pregnancy.

RESULTS: The differences in the faecal microbiome of one thousand lean and obese persons persist during gestation. Obese individuals have a less diverse and less rich microbiome throughout all trimesters of pregnancy. In the first trimester, 9 species differ significantly between lean and obese individuals, and 35 in the early third trimester, after adjusting for confounders. However, only one species remained significant after further adjusting for bowel transit time, which differed significantly between lean and obese participants. Additionally, obese individuals harbored a consistently lower potential to produce propionate in their gut microbiomes, even after adjustments.

CONCLUSIONS: The faecal microbiome adapts to pregnancy with some key differences between lean and obese mothers, even in late pregnancy. Crucially, there is an over-abundance of opportunistic pathogens in the microbiome of obese pregnant women in the third trimester. This may be a potential underexplored mechanism explaining the increased rates of pregnancy complications among obese patients. Diet, probiotics, or medication interventions to correct the gut microbiome of pregnant obese individuals could potentially improve their pregnancy outcomes.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12866-025-04473-8.