Advanced neuroimaging: A window into the neural correlates of fetal programming related to prenatal exposure to maternal depression and SSRIs

Intrauterine Exposure to Antidepressants or Maternal Depressive Symptoms and Offspring Brain White Matter Trajectories From Late Childhood to Adolescence

BACKGROUND

During pregnancy, both selective serotonin reuptake inhibitor (SSRI) exposure and maternal depression have been associated with poor offspring neurodevelopmental outcomes. In a population-based cohort, we investigated the association between intrauterine exposure to SSRIs and depressive symptoms and offspring white matter development from childhood to adolescence.

METHODS

Self-reported SSRI use was verified by pharmacy records. In midpregnancy, women reported on depressive symptoms using the Brief Symptom Inventory. Using diffusion tensor imaging, offspring white matter microstructure, including whole-brain and tract-specific fractional anisotropy (FA) and mean diffusivity, was measured at 3 assessments between ages 7 to 15 years. The participants were divided into 4 groups: prenatal SSRI exposure (n = 37 with 60 scans), prenatal depression exposure (n = 229 with 367 scans), SSRI use before pregnancy (n = 72 with 95 scans), and reference (n = 2640 with 4030 scans).

RESULTS

Intrauterine exposure to SSRIs and depressive symptoms were associated with lower FA in the whole-brain and the forceps minor at 7 years. Exposure to higher prenatal depressive symptom scores was associated with lower FA in the uncinate fasciculus, cingulum bundle, superior and inferior longitudinal fasciculi, and corticospinal tracts. From ages 7 to 15 years, children exposed to prenatal depressive symptoms showed a faster increase in FA in these white matter tracts. Prenatal SSRI exposure was not related to white matter microstructure growth over and above exposure to depressive symptoms.

CONCLUSIONS

These results suggest that prenatal exposure to maternal depressive symptoms was negatively associated with white matter microstructure in childhood, but these differences attenuated during development, suggesting catch-up growth.

Prenatal Antidepressant Exposure and Offspring Brain Morphologic Trajectory

Importance

Clinical decision-making on antidepressant treatment during pregnancy, particularly selective serotonin reuptake inhibitors (SSRIs), is challenging, as both prenatal SSRI exposure and maternal depressive symptoms may be associated with negative outcomes in offspring.

Objective

To investigate the association between intrauterine SSRI exposure and maternal depressive symptoms and structural brain development in offspring from mid-childhood to early puberty.

Design, Setting, and Participants

This prospective, population-based cohort study was embedded in the Generation R Study in Rotterdam, the Netherlands. All pregnant individuals with an expected delivery date between April 1, 2002, and January 31, 2006, were invited to participate. Data were analyzed from February 1 to September 30, 2022.

Exposure

Maternal-reported SSRI use verified by pharmacy records. In mid-pregnancy and 2 and 6 months after delivery, participants reported depressive symptoms using the Brief Symptom Inventory and were divided into 5 groups: SSRI use during pregnancy (n = 41; 80 scans), SSRI use only before pregnancy (n = 77; 126 scans), prenatal depressive symptoms without prenatal SSRI use (n = 257; 477 scans), postnatal depressive symptoms only (n = 74; 128 scans), and nonexposed control individuals (n = 2749; 4813 scans).

Main Outcomes and Measures

The main outcome was brain morphometry in offspring, including global and cortical brain volumes, measured at 3 magnetic resonance imaging assessments from 7 to 15 years of age.

Results

The study included 3198 mother-child dyads. A total of 3198 mothers (100%) identified as women; mean (SD) age at intake was 31.1 (4.7) years. Children (1670 [52.2%] female) underwent brain imaging assessment from 7 to 15 years of age with 5624 total scans. Most brain gray matter volumes showed an inverted U-shaped trajectory. Compared with nonexposed controls, children prenatally exposed to SSRIs had less cerebral gray matter (β [SE], -20 212.2 [7285.6] mm3; P = .006), particularly within the corticolimbic circuit, which persisted up to 15 years of age. Children exposed to SSRIs prenatally showed a steeper increase in volumes of the amygdala (age interaction: β [SE], 43.3 [13.4] mm3; P = .006) and fusiform gyrus (age interaction: β [SE], 168.3 [51.4] mm3; P = .003) from 7 to 15 years of age. These volumetric differences in the amygdala and fusiform observed in childhood did not persist until early adolescence. Prenatal depression was associated with a smaller volume in the rostral anterior cingulate gyrus (β [SE], -166.3 [65.1] mm3; P = .006), and postnatal depression was associated with a reduced fusiform gyrus (β [SE], -480.5 [189.2] mm3; P = .002). No association of SSRI use before pregnancy with brain outcomes was observed.

Conclusions and Relevance

The results of this cohort study suggest that prenatal SSRI exposure may be associated with altered developmental trajectories of brain regions involved in emotional regulation in offspring. Further research on the functional implications of these findings is needed.

A coordinate-based meta-analysis of human amygdala connectivity alterations related to early life adversities

By affecting core neurobiological systems early in development, early life adversities (ELAs) might confer latent vulnerability to future psychopathologies. This coordinate-based meta-analysis aims to identify significant convergent alterations in functional connectivity of the amygdala related to ELAs across resting-state and task-based fMRI-studies. Five electronic databases were systematically searched until 22 October 2020, retrieving 49 eligible studies (n = 3162 participants). Convergent alterations in functional connectivity related to ELAs between the amygdala and the anterior cingulate cortex (ACC) and left hippocampus were found. Sub-analyses based on hemisphere and direction showed that connectivity seeded in the right amygdala was affected and, moreover, revealed that connectivity with ACC was decreased. Analyses based on paradigm and age showed that amygdala-ACC coupling was altered during resting state and that amygdala-left hippocampus connectivity was mostly affected during task-based paradigms and in adult participants. While both regions showed altered connectivity during emotion processing and following adverse social postnatal experiences such as maltreatment, amygdala-ACC coupling was mainly affected when ELAs were retrospectively assessed through self-report. We show that ELAs are associated with altered functional connectivity of the amygdala with the ACC and hippocampus. As such, ELAs may embed latent vulnerability to future psychopathologies by systematically affecting important neurocognitive systems.

Perinatal and early childhood biomarkers of psychosocial stress and adverse experiences

The human brain develops through a complex interplay of genetic and environmental influences. During critical periods of development, experiences shape brain architecture, often with long-lasting effects. If experiences are adverse, the effects may include the risk of mental and physical disease, whereas positive environments may increase the likelihood of healthy outcomes. Understanding how psychosocial stress and adverse experiences are embedded in biological systems and how we can identify markers of risk may lead to discovering new approaches to improve patient care and outcomes. Biomarkers can be used to identify specific intervention targets and at-risk children early when physiological system malleability increases the likelihood of intervention success. However, identifying reliable biomarkers has been challenging, particularly in the perinatal period and the first years of life, including in preterm infants. This review explores the landscape of psychosocial stress and adverse experience biomarkers. We highlight potential benefits and challenges of identifying risk clinically and different sub-signatures of stress, and in their ability to inform targeted interventions. Finally, we propose that the combination of preterm birth and adversity amplifies the risk for abnormal development and calls for a focus on this group of infants within the field of psychosocial stress and adverse experience biomarkers. IMPACT: Reviews the landscape of biomarkers of psychosocial stress and adverse experiences in the perinatal period and early childhood and highlights the potential benefits and challenges of their clinical utility in identifying risk status in children, and in developing targeted interventions. Explores associations between psychosocial stress and adverse experiences in childhood with prematurity and identifies potential areas of assessment and intervention to improve outcomes in this at-risk group.

Prenatal Selective Serotonin Reuptake Inhibitor Exposure, Depression and Brain Morphology in Middle Childhood: Results from the ABCD Study

Background

Prenatal selective serotonin reuptake inhibitor (SSRI) exposure has been inconsistently linked to depression, and little is known about neural correlates. We examined whether prenatal SSRI exposure is associated with depressive symptoms and brain structure during middle childhood.

Methods

Prenatal SSRI exposure (retrospective caregiver report), depressive symptoms (caregiver-reported Child Behavior Checklist), and brain structure (magnetic resonance imaging-derived subcortical volume; cortical thickness and surface area) were assessed in children (analytic ns = 5420-7528; 235 with prenatal SSRI exposure; 9-10 years of age) who completed the baseline Adolescent Brain Cognitive Development Study session. Linear mixed-effects models nested data. Covariates included familial, pregnancy, and child variables. Matrix spectral decomposition adjusted for multiple testing.

Results

Prenatal SSRI exposure was not independently associated with depression after accounting for recent maternal depressive symptoms. Prenatal SSRI exposure was associated with greater left superior parietal surface area (b = 145.3 mm², p = .00038) and lateral occipital cortical thickness (b = 0.0272 mm, p = .0000079); neither was associated with child depressive symptoms. Child depression was associated with smaller global brain structure.

Conclusions

Our findings, combined with adverse outcomes of exposure to maternal depression and the utility of SSRIs for treating depression, suggest that risk for depression during middle childhood should not discourage SSRI use during pregnancy. Associations between prenatal SSRI exposure and brain structure were small in magnitude and not associated with depression. It will be important for future work to examine associations between prenatal SSRI exposure and depression through young adulthood, when risk for depression increases.

Associations between prenatal exposure of serotonergic medications and biobehavioural stress regulation: Protocol for systematic review and meta-analysis (Preprint)

Background

Up to 20% of mothers experience antenatal depression and approximately 30% of these women are treated with serotonergic psychotropic pharmacological therapy during pregnancy. Serotonergic antidepressants readily cross the placenta and the fetal blood-brain barrier, altering central synaptic serotonin signaling and potentially altering serotonin levels in the developing fetal brain.

Objective

The aim of this study is to assess the impact of prenatal exposure to serotonergic antidepressants, accounting for maternal mood disturbances, on markers of stress regulation during childhood.

Methods

We will follow PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and will search MEDLINE, Embase, CINAHL, PsycINFO, and ClinicalTrials.gov for full-length studies that assessed physiological (eg, cortisol level, heart rate variability, salivary amylase, pupillary size, C-reactive protein) indices of stress regulation in children of pregnant people who were treated with a serotonergic antidepressant at any point during pregnancy. We will assess the quality of observational studies using the Newcastle-Ottawa Scale and the quality of experimental studies using the Cochrane risk-of-bias tool. When possible, we will conduct a random-effects meta-analysis. If meta-analysis is not possible, we will conduct a narrative review. If a sufficient number of studies are found, we will perform subgroup analysis and assess outcomes measured by drug class, dose, trimester of exposure, and child’s age and gender.

Results

We registered our review protocol with PROSPERO (International Prospective Register of Systematic Reviews; CRD42021275750), completed the literature search, and initiated title and abstract review in August 2021. We expect to finalize this review by April 2022.

Conclusions

Findings should identify the impact of prenatal antidepressant effects on stress regulation and distinguish it from the impact of prenatal exposure to maternal mood disturbances. This review should inform decisions about serotonergic antidepressant use during pregnancy.

Trial Registration

PROSPERO CRD42021275750; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=275750

International Registered Report Identifier (IRRID)

PRR1-10.2196/33363

Global Network Organization of the Fetal Functional Connectome

Recent advances in brain imaging have enabled non-invasive in vivo assessment of the fetal brain. Characterizing brain development in healthy fetuses provides baseline measures for identifying deviations in brain function in high-risk clinical groups. We examined 110 resting state MRI data sets from fetuses at 19 to 40 weeks' gestation. Using graph-theoretic techniques, we characterized global organizational features of the fetal functional connectome and their prenatal trajectories. Topological features related to network integration (i.e., global efficiency) and segregation (i.e., clustering) were assessed. Fetal networks exhibited small-world topology, showing high clustering and short average path length relative to reference networks. Likewise, fetal networks' quantitative small world indices met criteria for small-worldness (σ > 1, ω = [-0.5 0.5]). Along with this, fetal networks demonstrated global and local efficiency, economy, and modularity. A right-tailed degree distribution, suggesting the presence of central areas that are more highly connected to other regions, was also observed. Metrics, however, were not static during gestation; measures associated with segregation-local efficiency and modularity-decreased with advancing gestational age. Altogether, these suggest that the neural circuitry underpinning the brain's ability to segregate and integrate information exists as early as the late 2nd trimester of pregnancy and reorganizes during the prenatal period. Significance statement. Mounting evidence for the fetal origins of some neurodevelopmental disorders underscores the importance of identifying features of healthy fetal brain functional development. Alterations in prenatal brain connectomics may serve as early markers for identifying fetal-onset neurodevelopmental disorders, which in turn provide improved surveillance of at-risk fetuses and support the initiation of early interventions.