The Role of Sex Steroids and Serotonin Brain Dynamics in Perinatal Mental Health

Study Overview
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Brief Summary
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Hormonal transitions such as across pregnancy and postpartum may trigger depressive episodes in some women. It is not known why, but estrogen sensitivity may play a critical role. A preclinical human risk model showed that depressive symptoms induced by pharmacological sex-hormone manipulation is linked to increases in serotonin transporter (SERT) brain binding, which lowers serotonergic brain tone. It is currently unknown if these findings translates to women across pre- to postpartum transitions. This longitudinal project studies a group of women who will deliver by planned caesarian, thus permitting the collection of cerebrospinal fluid (csf) containing central markers of serotonergic signaling, at the latest point in pregnancy. The women are followed across late pregnancy, delivery and 6 months postpartum to illuminate relations between sex-hormones, stress-regulation, estradiol sensitivity, csf markers of neurotransmission, serotonin transporter genotype variance, and potential development of subclinical or manifest depressive symptoms. Further, markers of relevance for the infant brain development and stress-regulation will be obtained from placenta tissue and umbilical cord blood. A subgroup of 70 women will participate in a brain imaging program early postpartum (week 3-5), which includes an evaluation of brain activity and structure and in vivo molecular brain imaging serotonergic markers. Thus, serotonergic markers in csf can be combined with postpartum molecular brain imaging of key features of serotonin signaling. Women in the imaging program are selected based on variation in their level of mental distress immediately postpartum (day 2-5). The study's main hypothesis is that women with high-expressing SERT genotypes are more sensitive to peripartum hormonal transition in terms of changes in serotonergic tone and emergence of depressive symptoms and that such an association will be stronger in the presence of candidate gene transcript biomarkers of oestrogen sensitivity. A further hypothesis is that in vivo molecular brain imaging and csf based serotonergic markers will be associated with depressive symptoms both early and later postpartum. Ideally, this project will provide a rationale for future targeted prevention and/or treatment of perinatal depression in women at high risk, which holds grand potential to protect not only mother but also infant brain health long-term.

Detailed Description
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Motivation: Major depressive disorder (MDD) affects twice as many women as men and women are at an increased risk during hormonal transition phases such as pregnancy and birth. A highly relevant subpopulation within the mixed MDD diagnostic category comprises women who develop perinatal depression (PND). PND is defined as a depressive episode with onset during pregnancy or up to 4 weeks postpartum, however epidemiological studies show that the risk of developing depression is heightened for 6 months postpartum. PND affects 10-15% of mothers postpartum. Why certain women are at high risk of developing perinatal depression (PND) remains unclear but recent studies suggest that these women might be particularly sensitive to the transition from high levels of placenta-produced sex-steroids in pregnancy to the hormone withdrawal phase postpartum. Further, pharmacologically induced changes in ovarian sex-hormones can produce depressive symptoms in a subgroup of otherwise healthy women and that the emergence of depressive symptoms is linked to both estrogen fluctuations and increases in serotonin transporter (SERT) brain binding (which putatively lowers serotonergic brain tone). Intriguingly, common gene variants that index SERT expression levels show gene BY environment associations with risk for depression, such that high-expressing SERT genotypes render women more vulnerable to depressive symptoms early - but not late - postpartum in a gene-dose dependent manner. Further, DNA methylation and gene expression markers of estradiol sensitivity predispose to PND and are linked to the estradiol stimulation phase in the pharmacological manipulation of sex-steroids risk model, thus constituting a candidate biomarker for PND. It is currently unknown if estradiol sensitivity during pregnancy confers to PND risk through mechanism that (transiently) affect serotonergic tone in susceptible women. Changes in brain function late in pregnancy may extend to the early postpartum and shape how the brain integrates additional neurobiological changes that are associated with the postpartum hormonal withdrawal phase. This study will examine these mechanisms in a group of pregnant women that are followed from late pregnancy across early to late postpartum up to 6 month. Natural variation in SERT-genotypes provides a unique opportunity to specifically address the interaction between SERT-gene expression-capacity and estradiol exposure through pregnancy in processes driving changes in serotonergic tone, brain structure and activity, and mental health from late pregnancy to 6 months postpartum. The time-points comprise: basic program: 2-5 days postpartum, 6 weeks postpartum and 6 months postpartum for all participants and for the imaging program participants: 2-5 days postpartum, 3-5 weeks postpartum, 12 weeks postpartum, 6 months postpartum. By including women who undergo planned caesarean section, cerebrospinal fluid (CSF) can be obtained and thus, for the first time combine CSF markers of serotonergic tone and other transmitter systems (serotonin, 5-hydroxyindolacetic acid, other monoamines, γ-aminobutyric acid) with molecular brain imaging methods that index serotonergic tone (i.e. serotonin 4 receptor binding) Aims: Determine if depressive symptoms from late pregnancy to 6 months postpartum map onto molecular brain imaging markers of serotonin signaling early postpartum (week 3-5), and evaluate if such markers and/or symptoms are dependent on serotonin transporter genotype and/or predicted by candidate gene transcription biomarkers for estrogen sensitivity. Evaluate how markers of stress-regulation capacity, brain activity, brain structure (hippocampal volume) and central markers of neurotransmission are associated with the emergence of depressive symptoms in women postpartum. Map the association between serotonin-4 receptor binding and cerebrospinal fluid markers of serotonergic tone (serotonin and 5-hydroxyindolacetic acid levels). Determine if markers of mental distress in women during pregnancy and the postpartum period are associated with infant markers of stress-regulation and serotonergic signaling in placenta and umbilical cord blood. Hypotheses: Women with high-expressing SERT genotypes are more sensitive to estradiol exposure in late pregnancy in terms of changes in proxies for serotonergic tone (PET imaging or csf based) and emergence of depressive symptoms in late pregnancy and/or postpartum and such an association will be stronger in the presence of candidate gene transcript PND biomarkers. CSF levels of 5-hydroxyindolacetic acid are associated with serotonin 4 receptor brain PET (Positron Emission Tomography) binding. Study design: 150 pregnant women between 18-40 years of age who deliver by planned caesarean section, due to breech presentation of the fetus or previous caesarean section, will be included in a longitudinal study. Participants will be recruited at the midwife clinic of Rigshospitalet, Copenhagen, Denmark. Based on natural variation in European populations the expected distribution of high vs. low expressing SERT genotypes is 40/60, respectively, thus genotype status can be included in the analysis structure. Self-reported psychometrics and questionnaires will be collected online at inclusion, across the pre- to postpartum transition and up to 6 months postpartum (basic program: 2-5 days postpartum, 6 weeks postpartum and 6 months postpartum; imaging program: 2-5 days postpartum, 3-5 weeks postpartum, 12 weeks postpartum, 6 months postpartum). CSF will be collected as part of the anesthetic procedures for a planned caesarean section, thus avoiding any additional invasive procedures. CSF markers of serotonergic tone (serotonin and its main metabolite, 5-HIAA) will be measured by HPLC techniques. Corresponding blood samples for determining relevant biomarkers (sex-steroids, DNA, mRNA and microRNA) and saliva for hypothalamic-pituitary-adrenal axis dynamics, will be taken just before the planned caesarean section. Hair from mother and infant will be collected around delivery for further cortisol analyses. Placenta tissue and umbilical cord blood will also be collected for determining relevant markers of serotonergic and hypothalamic-pituitary-adrenal axis functioning. A subgroup of the study cohort selected towards high (N=35) or low risk for later manifest PND (N=35), based on symptoms of mental distress 2-5 days postpartum (in-house interview, high-risk scores correspond to at least 12 on the Kennerley Maternity Blues Questionnaire and at least 8 on Stein's Maternity Blues Scale), will participate in an extended brain imaging program. This program will include 5-HT4R ([11C]SB207145) PET, structural MRI, functional MRI (including emotional processing, reward processing and resting state fMRI), neuropsychological testing and face to face rating of mental state with a semi-structured interview (HAM-D17). The study includes long-term follow-up at six months. Collected data will enter the Center for Integrated Molecular Brain Imaging database, thus providing a basis for longitudinal follow-up, data sharing and crossvalidation. Statistics: Power calculations based on inter-subject variability of the 5-HT4R show that an imaging group size of 35 is required to detect a 15% difference with a power of 0.8 for the brain regions of interest. With the full cohort number of 150 and due to oversampling of high and low risk women, about 25 women are expected to develop manifest PND episodes and more will display subclinical depressive symptoms, which will allow for correlation analyses with relevant outcome parameters including the candidate gene transcript based biomarker of estrogen sensitivity. Highly correlated self-reported psychometric outcomes will be included in a latent variable construct of self-reported mental state (composite measure) using structural equation modelling. Ethics: The PET scans convey no known risk for adults. Infants will not be exposed to radiation and will be nursed by special staff or a close relative while the mother is scanned. Participants who develop levels of mental distress or depressive symptoms that approach clinical thresholds will be referred to relevant and timely psychiatric care. The study has been approved by the local ethics committee.

Official Title
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The Role of Sex Steroids and Serotonin Brain Dynamics in Perinatal Mental Health

Conditions
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Major Depressive Disorder, Perinatal Depression

Intervention / Treatment
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* Other: Pregnancy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18-40 years Healthy pregnant women planned to deliver by caesarean section due to breech position of the fetus or previous caesarean section. Exclusion Criteria: Current or previous severe psychiatric disorder such as psychotic disorders, eating disorder and bipolar disorder or current or previous psychiatric disorder requiring hospitalization. Current or previous neurological diseases, severe somatic disease, severe postpartum hemorrhage or use of medication that can interfere with study outcomes Severe disease or malformations in infants Obesity or underweight (pre-gestational BMI below 18 or above 35) Not fluent in Danish or severe visual or hearing impairments Earlier or present learning disabilities MRI contraindications (claustrophobia, metal implants) Previous exposure to radioactivity > 10 millisievert (mSv) within the last year Alcohol or drug abuse

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Basic, non-imaging group<br>Pregnant women who will deliver by planned caesarian. Participants enrolled in the study that are not eligible for the imaging subgroup. All participants start in the basic program. Includes collection of blood, cerebrospinal fluid, saliva, hair, placenta tissues, umbilical cord blood and psychometrics. | Other: Pregnancy<br>* Peripartum transition from pregnant to postpartum state<br>|
| Extended, imaging group<br>A subgroup of 70 pregnant women who will deliver by planned caesarian selected towards either high (N=35) or low (N=35) risk for perinatal depression will undergo brain imaging in addition to the elements of the basic program. The extended imaging program includes functional and structural magnetic resonance imaging, positron emission tomography (PET) and a semistructured interview for depression symptoms (HAM-D17). | Other: Pregnancy<br>* Peripartum transition from pregnant to postpartum state<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Depressive symptoms | Edinburgh Postnatal Depression Scale. Score range: 0-30. Higher scores indicate more symptoms of postpartum depression. Total group | Week 3-6 postpartum | 
| Depressive symptoms | Score on the Hamilton 17-item depression scale. Score range: 0-52. Higher scores indicate more depressive symptoms. Assessed in imaging group | Week 3-6 postpartum | 
| Gene transcript and DNA methylation markers of estrogen sensitivity | 116 a priori defined gene transcripts, which where differentially expressed in third trimester of women who later developed perinatal depression with postpartum onset relative to pregnant women who did not and to other depressed (reference Mehta et al, 2014, Psychological Medicine) and confirmed to be coupled to estrogen fluctuations (Mehtaet al. 2018 British Journal of Psychiatry) will be evaluated in the total group. Also DNA methylation of the genes of these transcripts will be determined and analysed in terms of their predictive value (above chance) for perinatal depression. | Prior to caesarean section | 
| Cerebral serotonin 4 receptor binding postpartum | Latent variable construct of brain 5-HT4R level based on quantification of 5-HT4R binding from 11C-SB207145 positron emission tomography in primary volumes of interest; neocortex, nucleus caudatus, putamen and hippocampus. Assessed in imaging group. | Week 3-6 postpartum | 
| CSF levels of GABA | Assessed in total group | On day of caesarean section | 
| CSF levels of serotonin metabolite (5-HIAA) | Assessed in total group | On day of caesarean section | 
| Cortisol awakening response | Cortisol awakening response, area under the curve with respect to baseline from 0 to 60 minutes from awakening. | Week 3-6 postpartum | 
| Hair cortisol level mothers | Provides an estimate of cortisol exposure up to 6 months prior to delivery, total group | On day of caesarean section. | 
| Hair cortisol level newborns | Provides an estimate of fetal cortisol exposure, infants from total group | Day 0-5 postpartum. | 
| Hippocampal volumes | Hippocampal brain volume (including hippocampus) from structural MRI, imaging group. | Week 3-6 postpartum. | 
| functional MRI response to reward | fMRI (BOLD response) based assessment of brain activity in response to reward, relative to non-reward, stimuli. Assessed in imaging cohort | Week 3-6 postpartum. | 
| Resting state functional connectivity MRI | rsfMRI based spontaneous co-fluctuations in low frequency BOLD signal, (functional connectivity). Assessed with rsfMRI scan in the resting state, i.e. non-goal oriented spontaneous thought and awake. Assessed in imaging group. | Week 3-6 postpartum | 
| Change in epigenetic SERT status | Change in epigenetic SERT status from late pregnancy to postpartum week 3-6. | From just before delivery to 3-6 weeks postpartum | 
| Concentration of inflammatory markers, i.e hsCRP and immunoactive cytokines, in peripheral blood | Composite measure of hsCRP, TNF-α, IL-6, IL-18 and IL-10 levels, total group | At week 3-6 | 
| functional MRI response to emotional faces | fMRI (BOLD response) based assessment of brain activity to emotionally salient, relative to neutral, stimuli. Assessed in imaging cohort. | Week 3-6 postpartum. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Depressive symptoms | Score on the Hamilton 17-item depression scale. Score range: 0-52. Higher scores indicate more depressive symptoms. Assessed in imaging group | Day 3-5 postpartum | 
| Depressive symptoms | Score on the Hamilton 17-item depression scale. Score range: 0-52. Higher scores indicate more depressive symptoms. Assessed in imaging group | Week 12 postpartum | 
| Depressive symptoms | Edinburgh Postnatal Depression Scale. Score range: 0-30. Higher scores indicate more symptoms of postpartum depression. Assessed in total group | Day 3-5 postpartum | 
| Depressive symptoms | Edinburgh Postnatal Depression Scale. Score range: 0-30. Higher scores indicate more symptoms of postpartum depression. Assessed in all | 6 months postpartum | 
| CSF levels of serotonin | Assessed in total group | On day of caesarean section | 
| CSF levels of dopamine metabolites | Assessed in total group | On day of caesarean section | 
| CSF levels of noradrenaline metabolites | Assessed in total group | On day of caesarean section | 
| CSF levels of inflammatory markers | Composite measure of IFN-c, IFN-alfa TNF-alfa og IL-6, in total group | On day of caesarean section | 
| Estradiol level | Estradiol level in peripheral blood, total group | Prior to caesarean section. | 
| Estradiol level | Estradiol level peripheral blood, total group | At week 3-6 postpartum. | 
| Change in estradiol level | Estradiol change pre- to postpartum, peripheral blood total group | From baseline (caesarean section to week 3-6 postpartum) | 
| Progesterone level | Progesterone level in peripheral blood | Prior to caesarean section. | 
| Progesterone level | Progesterone level in peripheral blood | At week 3-6 postpartum. | 
| Change in progesterone level | Progesterone change pre- to postpartum, peripheral blood total group | From baseline (caesarean section to week 3-6 postpartum) | 
| Allopregnanolone level | Allopregnanolone level in peripheral blood | Prior to caesarean section. | 
| Allopregnanolone level | Allopregnanolone level in peripheral blood | At week 3-6 postpartum. | 
| Change in allopregnanolone level | Change in allopregnanolone level in peripheral blood | From baseline (caesarean section to week 3-6 postpartum) | 
| Change in cortisol level | Cortisol change pre- to postpartum, peripheral blood total group | From baseline (caesarean section to week 3-6 postpartum) | 
| Cortisol awakening response | Cortisol awakening response, area under the curve with respect to baseline from 0 to 60 minutes from awakening. | Week 12 postpartum | 
| Cortisol awakening response | Cortisol awakening response, area under the curve with respect to baseline from 0 to 60 minutes from awakening. | Prior to caesarean section | 
| Change in cortisol awakening response | Change in cortisol awakening response, from caesarean section to 3-6 weeks postpartum. | ´From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the SERT gene | Methylation status for the SERT gene, total group | Prior to caesarean section | 
| DNA methylation of the SERT gene | DNA Methylation status for the SERT gene, total group | Week 3-6 postpartum | 
| DNA methylation of the FK506-binding protein 51 (FKBP5) gene | Methylation status for the FK506-binding protein 51 (FKBP5) gene, total group | Prior to caesarean section. | 
| DNA methylation of the FK506-binding protein 51 (FKBP5) gene | Methylation status for the FK506-binding protein 51 (FKBP5) gene, total group | Week 3-6 postpartum | 
| Change in DNA methylation of the FK506-binding protein 51 (FKBP5) gene | Change in methylation status for the FK506-binding protein 51 (FKBP5) gene from late pregnancy to postpartum week 3-6. | From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the glucocorticoid receptor gene | Methylation status for the glucocorticoid receptor gene, total group | Prior to caesarean section. | 
| DNA methylation of the glucocorticoid receptor gene | Methylation status for the glucocorticoid receptor gene, total group | Week 3-6 postpartum | 
| Change in DNA methylation of the glucocorticoid receptor gene | Change in methylation status for the glucocorticoid receptor gene from late pregnancy to postpartum week 3-6. | From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the COMT gene | Methylation status for the COMT gene, total group | Prior to caesarean section. | 
| DNA methylation of the COMT gene | Methylation status for the COMT gene, total group | Week 3-6 postpartum | 
| Change in DNA methylation of the COMT gene | Change in methylation status for the COMT gene from just before delivery to 3-6 weeks postpartum | From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the MAO-A gene | Methylation status for the MAO-A gene, total group | Prior to caesarean section. | 
| Change in DNA methylation of the MAO-A gene | Change in methylation status for the MAO-A gene, total group | From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the MAO-A gene | Methylation status for the MAO-A gene, total group | Week 3-6 postpartum | 
| DNA methylation of the oxytocin receptor gene | Methylation status for the oxytocin receptor gene, total group | Prior to caesarean section. | 
| DNA methylation of the oxytocin receptor gene | Methylation status for the oxytocin receptor gene, total group | Week 3-6 postpartum | 
| Change in DNA methylation of the oxytocin receptor gene | Change in methylation status for the oxytocin receptor gene, total group | From baseline (caesarean section to week 3-6 postpartum) | 
| DNA methylation of the oxytocin gene | Methylation status for the oxytocin gene, total group | Prior to caesarean section. | 
| DNA methylation of the oxytocin gene | Methylation status for the oxytocin gene, total group | Week 3-6 postpartum | 
| Change in DNA methylation of the oxytocin gene | Change methylation status for the oxytocin gene, total group | From baseline (caesarean section to week 3-6 postpartum) | 
| Systemic inflammation peripheral blood hsCRP and immunoactive cytokines | Composite measure of hsCRP, TNF-α, IL-6, IL-18 and IL-10 levels, total group | Prior to caesarean section. | 
| Change in systemic inflammation peripheral blood hsCRP and immunoactive cytokines | Change in composite measure of hsCRP, TNF-α, IL-6, IL-18 and IL-10 levels, total group | From baseline (caesarean section to week 3-6 postpartum | 
| Self reported family history of mood disorders | Family History Assessment Module (OS-FHAM). Number of first degree relatives with a history of depressive episodes or bipolar disorder. Total group. | Day 3-5 postpartum or before | 
| Self reported impulsiveness score | Barratt Impulsiveness Scale (BIS-11), self-reported. Range: 30-120. Total group. | Day 3-5 postpartum or before | 
| Self reported Neuroticism score from NEO personality questionnaire | NEO-PI-R - Revised NEO Personality Inventory, self-reported. Participants may score 20-80 for each of the personality traits: openness, conscientiousness, extraversion, agreeableness, and neuroticism. The higher the score, the more prominent is the personality trait. Total group. | Day 3-5 postpartum or before | 
| Self reported parental bonding quality | Parental bonding instrument (PBI), both parents, self-reported. Total group. | Day 3-5 postpartum or before | 
| Self-reported perceived stress | Perceived Stress Scale (PSS), range 0-40, a score of 0 indicates no perceived stress. Total group. | Day 3-5 postpartum | 
| Self-reported perceived stress | Perceived Stress Scale (PSS), range 0-40, a score of 0 indicates no perceived stress. Total group. | Week 3-6 postpartum | 
| Change in self-reported perceived stress | Change in Perceived Stress Scale (PSS), range 0-40, a score of 0 indicates no perceived stress. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported anhedonia | Snaith-Hamilton Pleasure Scale (SHAPS), range 0-14, a score of 0 indicates no self-reported anhedonia. Total group. | Day 3-5 postpartum | 
| Self-reported anhedonia | Snaith-Hamilton Pleasure Scale (SHAPS), range 0-14, a score of 0 indicates no self-reported anhedonia. Total group. | Week 3-6 postpartum | 
| Change in self-reported anhedonia | Change in Snaith-Hamilton Pleasure Scale (SHAPS) score, range 0-14, a score of 0 indicates no self-reported anhedonia. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported rumination | Rumination Response Scale (RRS), range 22-88, a score of 22 indicates no ruminative symptoms. Total group. | Day 3-5 postpartum | 
| Self-reported rumination | Rumination Response Scale (RRS), range 22-88, a score of 22 indicates no ruminative symptoms. Total group. | Week 3-6 postpartum | 
| Change in elf-reported rumination | Change in Rumination Response Scale (RRS) score, range 22-88, a score of 22 indicates no ruminative symptoms. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported mood | Profile of Mood States (POMS), range 0-260, a score of 0 indicates no mood disturbance. Total group. | Day 3-5 postpartum | 
| Self-reported mood | Profile of Mood States (POMS), range 0-260, a score of 0 indicates no mood disturbance. Total group. | Week 3-6 postpartum | 
| Change in self-reported mood | Change in Profile of Mood States (POMS) score, range 0-260, a score of 0 indicates no mood disturbance. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported sleep quality | Pittsburgh Sleep Quality Index (PSQI), range 0-21, a score of 0 indicates a healthy sleep quality. Total group. | Day 3-5 postpartum | 
| Self-reported sleep quality | Pittsburgh Sleep Quality Index (PSQI), range 0-21, a score of 0 indicates a healthy sleep quality. Total group. | Week 3-6 postpartum | 
| Change in self-reported sleep quality | Change in Pittsburgh Sleep Quality Index (PSQI), range 0-21, a score of 0 indicates a healthy sleep quality. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported psychiatric symptoms | Brief symptom Inventory-53 item (BSI-53), range 0-212, increasing score means worsening of symptoms.Total group. | Day 3-5 postpartum | 
| Self-reported psychiatric symptoms | Brief symptom Inventory-53 item (BSI-53), range 0-212, increasing score means worsening of symptoms.Total group. | Week 3-6 postpartum | 
| Change in self-reported psychiatric symptoms | Change in Brief symptom Inventory-53 item (BSI-53) score, range 0-212, increasing score means worsening of symptoms.Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported well-being | WHO-5 well-being index, range 0-100, low score means less well-being. Total group. | Day 3-5 postpartum | 
| Self-reported well-being | WHO-5 well-being index, range 0-100, low score means less well-being. Total group. | Week 3-6 postpartum | 
| Change in self-reported well-being | Change in WHO-5 well-being index, range 0-100, low score means less well-being. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported anxiety | State Trait Anxiety Inventory (STAI-AD-D), state and trait subscales each have a range of 20-80, 20 means no anxiety. Total group. | Day 3-5 postpartum | 
| Self-reported anxiety | State Trait Anxiety Inventory (STAI-AD-D), state subscale range 20-80, 20 means no anxiety. Total group. | Week 3-6 postpartum | 
| Change in self-reported anxiety | Change in State Trait Anxiety Inventory (STAI-AD-D) score, state subscale range 20-80, 20 means no anxiety. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Self-reported obsessive and compulsive symptoms | Obsessive-Compulsive Inventory (OCI) score, self-reported, range 0-72, higher scores indicate more symptoms. Total group. | Day 3-5 | 
| Self-reported obsessive and compulsive symptoms | Obsessive-Compulsive Inventory (OCI) score, self-reported, range 0-72, higher scores indicate more symptoms. Total group. | Week 3-6 postpartum | 
| Change in self-reported obsessive and compulsive symptoms | Change in Obsessive-Compulsive Inventory (OCI) score, self-reported, range 0-72, higher scores indicate more symptoms. Total group. | Change from day 3-5 to week 3-6 postpartum | 
| Performance on Simple Reaction Time | Performance on Simple Reaction Time, in imaging cohort. | Week 3-6 postpartum | 
| Gray matter brain volume prefrontal cortex and anterior cingulate cortex | Gray matter brain volume prefrontal cortex and anterior cingulate cortex | At week 3-6 postpartum | 
| Serotonergic turnover in placenta | Composite measure of serotonin, tryptophan og tryptofan hydroxylase levels relative to 5-HIAA, in placenta sample. Infants from total group | At delivery. | 
| 11-beta-hydroxysteroid dehydrogenase type 2 activity in placenta | 11-beta-hydroxysteroid dehydrogenase type 2 activity in placenta. Infants from total group | At delivery | 
| Methylation status of genes relevant for stress-hormone regulation in placenta | Composite measure of methylation status for the FKBP5, glucocorticoid receptor, 11-beta hydroxysteroid dehydrogenase type 2 genes. Infants from total group | At delivery | 
| Methylation status of genes related to serotonergic signaling in placenta | Composite measure of the methylation status for monoamine oxidase, serotonin receptor and serotonin transporter genes. Infants from total group | At delivery | 
| Methylation status and gene transcript profiles of relevance for early brain development and stress regulation in newborn infants | Composite measure of methylation status and gene transcript profiles of Glucocorticoid receptor, FKBP5, oxytocin and oxytocin receptors, Brain-derived neurotrophic factor (BDNF) genes. Assessed in blood from umbilical cord blood sample from infants, total group. | At delivery. |