Postpartum Mood Disorders and Thyroid Autoimmunity

Thyroid Predictors of Postpartum Mood Disorders

Postpartum mood disorders (PMD) are currently among the leading causes of maternal postpartum morbidity and mortality. PMD include the conditions of postpartum blues (PB), postpartum depression (PPD), and postpartum psychosis. The pathogenesis of PMDs are ambiguous, and there are no reliable prenatal predictive markers despite current research efforts. Even though reliable indicators have not been found, leading ideas suggest an etiology of hormonal fluctuations. Although thyroid markers have long been linked to psychiatric disorders such as major depressive disorder (MDD), how they correlate with PMDs is still unclear. This study aimed to evaluate the pathophysiological link between thyroid function, PMDs, and the usefulness of thyroid markers as indicators of their occurrence and severity. The methodology consisted of a narrative literature review. Several inclusion and exclusion criteria were used to filter the results of literature searches in PubMed. Studies were included if they discussed any marker related to thyroid endocrinology in relation to the incidence or pathophysiology of any PMD. Both primary and secondary analyses were included. The permissive inclusion criteria were used due to the relative scarcity of research on the topic and the ambiguous pathophysiology of PMD. The results demonstrated the potential utility of thyroid autoimmunity as a predictor of late-onset PPD. Hypothyroidism, low euthyroid hormone levels, and the presence of thyroid autoantibodies were correlated with increased incidence of PPD and late postpartum depressive symptoms, past the timeline of PB. Most notably a rapid postpartum drop in cortisol level may precipitate thyroid autoimmunity in anti-thyroid peroxidase (TPO) antibody positive women, which could eventually produce a hypothyroid phase associated with depressive symptoms. There was insufficient evidence to suggest a relationship with postpartum psychosis. In conclusion, the exact pathophysiological mechanisms of PMDs remain ambiguous, but TPO-antibodies in the third trimester may be a predictor of late PPD.

Postpartum depression in maternal thyroidal changes

Evidence in the literature has suggested that there may be an association between thyroid antibodies and depression during pregnancy and in the postpartum period. Thus, this study aims to conduct a systematic review on the prevalence of postpartum depression (PPD) in women with thyroid abnormalities during pregnancy or in the postpartum period. For this review, we used four databases (PubMed, Lilacs, Scielo, and Scopus). Fifteen studies were selected; one study used a case–control design, four used a cross-sectional design and ten utilized prospective cohort designs. All studies were restricted to up to 1 year postpartum, and 46.7% focused on a period between immediate postpartum and 6 months postpartum. Estimates of the prevalence of PPD in pregnant women with thyroid disorders ranged between 8.3% and 36.0%. For follow-up studies, the cumulative incidence of self-reported depression from the primary episode in the first postpartum year was 6.3% in a high-city survey. Although some authors consider the status of positive anti-TPO antibodies to be a possible marker of vulnerability to depression , it is not yet possible to conclude whether thyroid function in the pregnancy-puerperal cycle is involved with the development of PPD.

Subclinical thyroid dysfunction and major depressive disorder

PURPOSE

This review attempts to investigate the link between subclinical thyroid dysfunction (SCH) and major depressive disorder (MDD). It has been speculated that SCH may be related to MDD through an autoimmune mechanism.

METHODS

A comprehensive literature search was conducted in the PubMed database for relevant research and review articles.

RESULTS

There appears to be an association between an autoimmune mechanism, possibly involving the thyroid gland, and depressive disorders, but the available evidence is so far inconclusive.

CONCLUSION

Lifetime prevalence of depression is significantly higher in patients with SCH, a finding reflecting a possible effect of SCH in lowering the threshold for the emergence of MDD. The relationship between SCH and MDD is, however, not clear, with large and well-designed studies investigating possible links between reference-range thyroid hormone levels and MDD having as yet found no relation between the two.

Development and validation of a machine learning algorithm for predicting the risk of postpartum depression among pregnant women

OBJECTIVE

There is a scarcity in tools to predict postpartum depression (PPD). We propose a machine learning framework for PPD risk prediction using data extracted from electronic health records (EHRs).

METHODS

Two EHR datasets containing data on 15,197 women from 2015 to 2018 at a single site, and 53,972 women from 2004 to 2017 at multiple sites were used as development and validation sets, respectively, to construct the PPD risk prediction model. The primary outcome was a diagnosis of PPD within 1 year following childbirth. A framework of data extraction, processing, and machine learning was implemented to select a minimal list of features from the EHR datasets to ensure model performance and to enable future point-of-care risk prediction.

RESULTS

The best-performing model uses from clinical features related to mental health history, medical comorbidity, obstetric complications, medication prescription orders, and patient demographic characteristics. The model performances as measured by area under the receiver operating characteristic curve (AUC) are 0.937 (95% CI 0.912 - 0.962) and 0.886 (95% CI 0.879-0.893) in the development and validation datasets, respectively. The model performances were consistent when tested using data ending at multiple time periods during pregnancy and at childbirth.

LIMITATIONS

The prevalence of PPD in the study data represented a treatment prevalence and is likely lower than the illness prevalence.

CONCLUSIONS

EHRs and machine learning offer the ability to identify women at risk for PPD early in their pregnancy. This may facilitate scalable and timely prevention and intervention, reducing negative outcomes and the associated burden.

Mother and Infant Nutrition Investigation in New Zealand (MINI Project): Protocol for an Observational Longitudinal Cohort Study

Background

Thyroid dysfunction is associated with cognitive impairment, mood disturbance, and postnatal depression. Sufficient thyroid hormone synthesis requires adequate intake of iodine, selenium, and iron. Iodine deficiency was historically a problem for New Zealand, and initiatives were introduced to overcome the problem: (1) mandatory fortification of all bread (except organic) with iodized salt (2009) and (2) provision of subsidized iodine supplements for pregnant and breastfeeding women (2010). Subsequent to these initiatives, most adults and children have adequate iodine status; however, status among breastfeeding women and their infants remains unclear. This paper outlines the methodology of the Mother and Infant Nutrition Investigation (MINI) study: an observational longitudinal cohort study of breastfeeding women and their infants.

Objective

This study will determine (1) women’s iodine intake and status among supplement users and nonusers; (2) women’s intake and status of iodine, selenium, and iron relating to thyroid function; (3) associations between women’s selenium status, thyroid function, and postnatal depression; (4) infants’ iodine and selenium status relating to first year neurodevelopment.

Methods

Breastfeeding women aged over 16 years with a healthy term singleton infant were recruited from Manawatu, New Zealand. Participants attended study visits 3, 6, and 12 months postpartum. Maternal questionnaires investigated supplement use before and after birth, iodine knowledge, and demographic information. Dietary assessment and urine, blood, and breast milk samples were taken to measure iodine, selenium, and iron intake/status. The Edinburgh Postnatal Depression Scale was used repeatedly to screen for postnatal depression. Thyroid hormones (free triiodothyronine, free thyroxine, thyroid stimulating hormone, thyroglobulin, antithyroglobulin antibodies, and antithyroid peroxidase) were measured in blood samples, and thyroid gland volume was measured by ultrasound at 6 months postpartum. Infant iodine and selenium concentrations were determined in urine. The Ages and Stages Questionnaire was used to assess infant development at 4, 8, and 12 months.

Results

Data collection was completed. Biological samples analysis, excluding nail clippings, is complete. Data analysis and presentation of the results will be available after 2020.

Conclusions

This study will provide data on the current iodine status of breastfeeding women. It will also provide a greater understanding of the three essential minerals required for optimal thyroid function among breastfeeding women. The prospective longitudinal design allows opportunities to examine women’s mental health and infant neurodevelopment throughout the first year, a crucial time for both mothers and their infants.

Trial Registration

Australian New Zealand Clinical Trials Registry ACTRN12615001028594; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=369324

International Registered Report Identifier (IRRID)

DERR1-10.2196/18560

THE NEUROENDOCRINOLOGICAL ASPECTS OF PREGNANCY AND POSTPARTUM DEPRESSION

Introduction

Ties between the endocrine system and mental health are undeniably a consistent point of interest in modern day medicine. Furthermore, mental disturbances due to hormonal changes following childbirth have been mentioned in medical literature since Hippocrates. Considering the dramatic endocrine, paracrine and autocrine changes that occur during gestation, labour and postnatal phase, hormonal theories are not to be ignored in the treatment of postpartum disorders.

Results

Reproductive hormones are known to modulate behavioural, emotional and cognitive response, therefore rapid changes in estradiol and progesterone plasma concentrations during pregnancy and labour create a vulnerable terrain leading towards postpartum disorders. New research shows that women suffering from postpartum disorders have abnormal neural responses, suggesting a neuroendocrine explanation for postpartum syndromes.

Conclusion

To facilitate further research in this area, we present new information on several hormonal interactions and the psychiatric response involved in pregnancy and labour, offering an interdisciplinary outlook on pregnancy and postpartum disorders. There is enough evidence to suggest that estradiol, progesterone, oxytocin, cortisol and thyroid hormones are some of many hormones involved in postpartum syndromes and tackling their perinatal imbalance with pharmacological substituents or antagonists could be useful as an adjuvant form of treatment in future patients.

Postpartum Depression and Subsequent Autoimmune Diseases in Taiwan

Postpartum depression (PPD) is one of the most common examples of postnatal morbidity, but the subsequent risks of autoimmune diseases in patients with PPD have yet to be fully investigated. This nationwide population-based study utilized data of the National Health Insurance Research Database of Taiwan for the period from 1996 to 2013. In total, 45,451 women with primiparity were identified. Among them, 542 patients with PPD were enrolled as a study group while 2165 matched patients without PPD were enrolled as a control group. The demographic characteristics and comorbidities of the patients were analyzed, and Cox regression analysis was applied to calculate the hazard ratios for the risk of autoimmune diseases. Of the 2707 women enrolled in this study, 469 (17.3%) patients with newly diagnosed autoimmune diseases were identified, including 123 (22.7%) in the PPD group and 346 (16%) in the non-PPD group. After adjusting for confounding factors, it was determined that the patients with PPD had a significantly higher risk of subsequent autoimmune diseases (adjusted hazard ratio (aHR): 1.61, 95% confidence interval (CI): 1.30–1.99; p < 0.001). Specifically, increased risks of pernicious anemia (aHR: 3.85, 95% CI: 2.06–7.22), rheumatoid arthritis (aHR: 2.62, 95% CI: 1.28–5.39), and Graves’ disease (aHR: 1.57, 95% CI: 1.05–2.33) were observed in the PPD group. This study demonstrated that patients with PPD have higher risks of subsequent autoimmune diseases, especially pernicious anemia, rheumatoid arthritis, and Graves’ disease. This useful information provides physicians with clues regarding the associations between autoimmune diseases and PPD.

Autoimmune Abnormalities of Postpartum Thyroid Diseases

The year following parturition is a critical time for the de novo appearance or exacerbation of autoimmune diseases, including autoimmune thyroid disease. The vast majority of postpartum thyroid disease consists of postpartum thyroiditis (PPT) and the minority by Graves' disease and non-autoimmune thyroiditis. PPT has a worldwide prevalence ranging from 1 to 22% and averaging 5% based on a review published in 2012. Several factors confer risk for the development of PPT. Typically, the clinical course of PPT is characterized by three phases: thyrotoxic, hypothyroid, and euthyroid phase. Approximately half of PPT women will have permanent hypothyroidism. The best humoral marker for predictivity, already during the first trimester of gestation, is considered positivity for thyroperoxidase autoantibodies (TPOAb), though only one-third to half of such TPOAb-positive pregnant women will develop PPT. Nutraceuticals (such as selenium) or omega-3-fatty acid supplements seem to have a role in prevention of PPT. In a recent study on pregnant women with stable dietary habits, we found that the fish consumers had lower rates of positivity (and lower serum levels) of both TPOAb and thyroglobulin Ab compared to meat eaters. Finally, we remind the reader of other diseases that can be observed in the postpartum period, either autoimmune or non-autoimmune, thyroid or non-thyroid.