Effect of exposure to selective serotonin reuptake inhibitors in utero on fetal growth: potential role for the IGF-I and HPA axes

Molecular pathways in placental-fetal development and disruption

The first trimester of pregnancy ranks high in priority when minimizing harmful exposures, given the wide-ranging types of organogenesis occurring between 4- and 12-weeks' gestation. One way to quantify potential harm to the fetus in the first trimester is to measure a corollary effect on the placenta. Placental biomarkers are widely present in maternal circulation, cord blood, and placental tissue biopsied at birth or at the time of pregnancy termination. Here we evaluate ten diverse pathways involving molecules expressed in the first trimester human placenta based on their relevance to normal fetal development and to the hypothesis of placental-fetal endocrine disruption (perturbation in development that results in abnormal endocrine function in the offspring), namely: human chorionic gonadotropin (hCG), thyroid hormone regulation, peroxisome proliferator activated receptor protein gamma (PPARγ), leptin, transforming growth factor beta, epiregulin, growth differentiation factor 15, small nucleolar RNAs, serotonin, and vitamin D. Some of these are well-established as biomarkers of placental-fetal endocrine disruption, while others are not well studied and were selected based on discovery analyses of the placental transcriptome. A literature search on these biomarkers summarizes evidence of placenta-specific production and regulation of each biomarker, and their role in fetal reproductive tract, brain, and other specific domains of fetal development. In this review, we extend the theory of fetal programming to placental-fetal programming.

A Review of Serotonin in the Developing Lung and Neonatal Pulmonary Hypertension

Serotonin (5-HT) is a bioamine that has been implicated in the pathogenesis of pulmonary hypertension (PH). The lung serves as an important site of 5-HT synthesis, uptake, and metabolism with signaling primarily regulated by tryptophan hydroxylase (TPH), the 5-HT transporter (SERT), and numerous unique 5-HT receptors. The 5-HT hypothesis of PH was first proposed in the 1960s and, since that time, preclinical and clinical studies have worked to elucidate the role of 5-HT in adult PH. Over the past several decades, accumulating evidence from both clinical and preclinical studies has suggested that the 5-HT signaling pathway may play an important role in neonatal cardiopulmonary transition and the development of PH in newborns. The expression of TPH, SERT, and the 5-HT receptors is developmentally regulated, with alterations resulting in pulmonary vasoconstriction and pulmonary vascular remodeling. However, much remains unknown about the role of 5-HT in the developing and newborn lung. The purpose of this review is to discuss the implications of 5-HT on fetal and neonatal pulmonary circulation and summarize the existing preclinical and clinical literature on 5-HT in neonatal PH.

Prenatal serotonin reuptake inhibitor antidepressant exposure, SLC6A4 genetic variations, and cortisol activity in 6-year-old children of depressed mothers: A cohort study

Prenatal exposure to maternal depression and serotonin reuptake inhibitor (SRI) antidepressants both affect the development of the hypothalamic-pituitary-adrenal (HPA) system, possibly via the neurotransmitter serotonin (5HT). In a community cohort, we investigated the impact of two factors that shape prenatal 5HT signaling (prenatal SRI [pSRI] exposure and child SLC6A4 genotype) on HPA activity at age 6 years. Generalized estimating equation (GEE) models were used to study associations between cortisol reactivity, pSRI exposure, and child SLC6A4 genotype, controlling for maternal depression, child age, and sex (48 pSRI exposed, 74 nonexposed). Salivary cortisol levels were obtained at five time points during a laboratory stress challenge: arrival at the laboratory, following two sequential developmental assessments, and then 20 and 40 min following the onset of a stress-inducing cognitive/social task. Cortisol decreased from arrival across both developmental assessments, and then increased across both time points following the stress challenge in both groups. pSRI-exposed children had lower cortisol levels across all time points. In a separate GEE model, we observed a lower cortisol stress response among children with LG /S alleles compared with children with La/La alleles, and this was particularly evident among children of mothers reporting greater third trimester depressed mood. Our findings suggest that pSRI exposure and a genetic factor associated with modulating 5HT signaling shaped HPA reactivity to a laboratory stress challenge at school age.

Maternal serotonin: implications for the use of selective serotonin reuptake inhibitors during gestation†

Maternal use of antidepressants has increased throughout the last decades; selective serotonin reuptake inhibitors (SSRI) are the most prescribed antidepressants. Despite the widespread use of SSRI by women during reproductive age and pregnant women, an increasing amount of research warns of possible detrimental effects of maternal use of SSRI during pregnancy including low birthweight/small for gestational age and preterm birth. In this review, we revisited the impact of maternal use of SSRI during pregnancy, its impact on serotonin homeostasis in the maternal and fetal circulation and the placenta, and its impact on pregnancy outcomes-particularly intrauterine growth restriction and preterm birth. Maternal use of SSRI increases maternal and fetal serotonin. The increase in maternal circulating serotonin and serotonin signaling likely promotes vasoconstriction of the uterine and placental vascular beds decreasing blood perfusion to the uterus and consequently to the placenta and fetus with potential impact on placental function and fetal development. Several adverse pregnancy outcomes are similar between women, sheep, and rodents (decreased placental size, decreased birthweight, shorter gestation length/preterm birth, neonatal morbidity, and mortality) highlighting the importance of animal studies to assess the impacts of SSRI. Herein, we address the complex interactions between maternal SSRI use during gestation, circulating serotonin, and the regulation of blood perfusion to the uterus and fetoplacental unit, fetal growth, and pregnancy complications.

Brief Developmental Exposure to Fluoxetine Causes Life-Long Alteration of the Brain Transcriptome in Zebrafish

Fluoxetine (FLX) and other selective serotonin reuptake inhibitors are widely used to treat depressive disorders during pregnancy. Early-life exposure to FLX is known to disrupt the normal function of the stress axis in humans, rodents, and teleosts. We used a zebrafish line with a cortisol-inducible fluorescent transgene to study the effects of developmental daily exposure to FLX (54 µg/L) on the transcriptomic profile of brain tissues in exposed larvae and later as 6-month-old adults. High throughput RNA sequencing was conducted on brain tissues in unstressed and stressed conditions. Long-lasting effects of FLX were observed in telencephalon (Tel) and hypothalamus (Hyp) of adult zebrafish with 1927 and 5055 genes significantly (≥1.2 fold-change, false-discovery p-value < 0.05) dysregulated in unstressed condition, respectively. Similar findings were observed in Hyp with 1245 and 723 genes being significantly dysregulated in stressed adults, respectively. Differentially expressed genes converted to Homo sapiens orthologues were used for Ingenuity Pathway Analysis. The results showed alteration of pathways involved in neuroendocrine signaling, cholesterol metabolism and synaptogenesis. Enriched networks included lipid metabolism, molecular transport, and nervous system development. Analysis of putative upstream transcription regulators showed potential dysregulation of clocka and nr3c1 which control circadian rhythm, stress response, cholesterol metabolism and histone modifications. Several genes involved in epigenetic regulation were also affected by FLX, including dnmt3a, adarb1, adarb2, hdac4, hdac5, hdac8, and atf2. We report life-long disruptive effects of FLX on pathways associated with neuroendocrine signaling, stress response and the circadian rhythm, and all of which are implicated in the development of depressive disorders in humans. Our results raise concern for the persistent endocrine-disrupting potential of brief antidepressant exposure during embryonic development.

Venlafaxine deposition in the zygote disrupts the endocrine control of growth in juvenile zebrafish

The antidepressant venlafaxine can be found at levels nearing μg/L in waterways receiving municipal wastewater effluent, exposing non-target organisms, such as fish, to this chemical. We showed previously that zygotic exposure to venlafaxine alters neurodevelopment and behaviour in zebrafish (Danio rerio) larvae. Here, we tested the hypothesis that the zygotic deposition of venlafaxine disrupts endocrine pathways related to growth in zebrafish. This was carried out by microinjecting embryos (1-4 cell stage) with either 0, 1, or 10 ng venlafaxine. Zygotic venlafaxine deposition reduced the growth of fish after 30 days post-fertilization. Specific growth rate was particularly impacted by 1 ng venlafaxine. This growth retardation corresponded with the disruption of endocrine pathways involved in growth and metabolism. Venlafaxine exposed embryos displayed reduced transcript abundance of key genes involved in anabolic hormone action. Early-life venlafaxine exposure also reduced whole-body insulin and glucose content in juveniles. Target-tissue glucose uptake measurements indicated that high venlafaxine deposition preferentially increased glucose uptake to the brain. Zygotic venlafaxine did not affect feed intake nor altered the transcript abundance of key feeding-related peptides. Taken together, zygotic venlafaxine deposition compromises zebrafish growth by disrupting multiple endocrine pathways, and this study has identified key markers for potential use in risk assessment.

Neonatal Withdrawal Syndrome following Late in utero Exposure to Selective Serotonin Reuptake Inhibitors: A Systematic Review and Meta-Analysis of Observational Studies

INTRODUCTION

A clear picture of neonatal withdrawal signs due to in utero selective serotonin reuptake inhibitor (SSRI) exposure and its consequences is still missing.

OBJECTIVE

A systematic review and a meta-analysis were performed to provide an overview of neonatal withdrawal signs following late in utero exposure to SSRIs and to quantify the corresponding risks.

METHODS

MEDLINE, Web of Science, and Embase were searched from inception to January 2021. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed. English-language observational studies reporting on acute postpartum outcomes following late in utero exposure to SSRIs or SSRIs/venlafaxine were evaluated.

RESULTS

Of 2,269 citations reviewed, 79 studies were assessed for eligibility; 13 were included in the qualitative analysis of the literature, which allowed us to identify 26 signs. A meta-analysis was run separately for studies on SSRI exposure (n = 3) and those on SSRI/venlafaxine exposure (n = 6). Hypoglycemia was identified as a withdrawal sign based on the SSRI studies. Tremors, hypotonia, tachycardia, rapid breathing, respiratory distress, and hypertonia were identified as withdrawal signs based on the SSRI/venlafaxine studies.

CONCLUSIONS

The present work provides a framework for the identification of neonatal SSRI withdrawal syndrome. Tapering and discontinuation of antidepressant drugs before and during the early phase of pregnancy are worth attempting to prevent the occurrence of this syndrome.

Interactions between maternal fluoxetine exposure, the maternal gut microbiome and fetal neurodevelopment in mice

Selective serotonin reuptake inhibitors (SSRIs) are the most widely used treatment by women experiencing depression during pregnancy. However, the effects of maternal SSRI use on early offspring development remain poorly understood. Recent studies suggest that SSRIs can modify the gut microbiota and interact directly with particular gut bacteria, raising the question of whether the gut microbiome impacts host responses to SSRIs. In this study, we investigate effects of prenatal SSRI exposure on fetal neurodevelopment and further evaluate potential modulatory influences of the maternal gut microbiome. We demonstrate that maternal treatment with the SSRI fluoxetine induces widespread alterations in the fetal brain transcriptome during midgestation, including increases in the expression of genes relevant to synaptic organization and neuronal signaling and decreases in the expression of genes related to DNA replication and mitosis. Notably, maternal fluoxetine treatment from E7.5 to E14.5 has no overt effects on the composition of the maternal gut microbiota. However, maternal pretreatment with antibiotics to deplete the gut microbiome substantially modifies transcriptional responses of the fetal brain to maternal fluoxetine treatment. In particular, maternal fluoxetine treatment elevates localized expression of the opioid binding protein/cell adhesion molecule like gene Opcml in the fetal thalamus and lateral ganglionic eminence, which is prevented by maternal antibiotic treatment. Together, these findings reveal that maternal fluoxetine treatment alters gene expression in the fetal brain through pathways that are impacted, at least in part, by the presence of the maternal gut microbiota.

Fetal programming pathway from maternal mental health to infant cortisol functioning: The role of placental 11β-HSD2 mRNA expression

Placental 11β-HSD2 has been a focus of research for understanding potential fetal programming associated with maternal emotional disorders. This study examined the pathway from antenatal mental health via placental 11β-HSD2 mRNA to cortisol regulation in the infant offspring. This study reports on data obtained from 236 participants in the Mercy Pregnancy and Emotional Wellbeing Study (MPEWS). At term, placental tissue was collected within 30 min of birth from 52 participants meeting current criteria for a depressive disorder, and 184 control participants. Depressive disorders were diagnosed using the SCID-IV. In addition, antidepressant use, depressive and anxiety symptoms were measured in early and late pregnancy. Placental 11β-HSD2 mRNA expression was measured using qRT-PCR. Infant salivary cortisol samples were taken at 12 months of age. Women on antidepressant medication and with higher trait anxiety had higher placental 11β-HSD2 expression compared to women not taking medication. Furthermore, the offspring of women taking an antidepressant and who also had a current depressive disorder and high trait anxiety had high cortisol reactivity at 12 months of age and this was mediated through 11β-HSD2 mRNA expression. In contrast, offspring of women not taking antidepressant medication with depressive disorder and high anxiety there was low cortisol reactivity observed. Our findings suggest that the relationship between maternal antenatal depression and anxiety and infant cortisol reactivity is mediated through placental 11β-HSD2 mRNA expression. Furthermore, the direction differed for women taking antidepressants, where infant cortisol reactivity was high whereas when compared to those with unmedicated depression and anxiety, where infant cortisol reactivity was low.

Zygotic exposure to venlafaxine disrupts cortisol stress axis activity in multiple generations of zebrafish

Ubiquitous use of antidepressants has resulted in increased concentrations of these pharmaceuticals in waterways receiving municipal wastewater effluent. Amongst these, venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor, is commonly found at concentrations surpassing 1 ppb in surface waters. We recently showed that the deposition of venlafaxine in zebrafish (Danio rerio) embryos impacts neural development in the hypothalamus, suggesting the possibility of neuroendocrine disruptions due to this antidepressant. Here, we tested the hypothesis that early developmental exposure to venlafaxine disrupts the long-term functioning of the hypothalamus-pituitary-interrenal (HPI) axis in zebrafish. Embryos (1-4 cell stage) were injected with either 0, 1, or 10 ng venlafaxine, and the ontogeny of cortisol content, as well as changes in cortisol levels following a stressor in larvae and adults were assessed across 3 generations. Zygotic venlafaxine exposure did not affect the ontogeny of cortisol production, but there was a disruption in the cortisol response to stressor exposure, which was also evident in multiple generations. In the F₀ generation, venlafaxine exposure did not affect cortisol levels in response to stressor exposure in larvae, but adult females, and not males, showed an attenuated cortisol response compared to control fish. This reduction in cortisol levels in the females was rescued by stimulation with adrenocorticotropic hormone, suggesting that the disruption was at the level of the hypothalamus-pituitary axis. Venlafaxine-mediated disruption in HPI axis functioning was also evident in the F₁ and F₂ generations, including impaired cortisol responses to a stressor in adult female and larval fish, respectively. Taken together, our results suggest that venlafaxine is an endocrine disruptor, and early developmental exposure to this antidepressant may have long-term and generational consequences on cortisol stress axis activity in zebrafish.

Antenatal Antidepressant Prescription Associated With Reduced Fetal Femur Length but Not Estimated Fetal Weight: A Retrospective Ultrasonographic Study

PURPOSE/BACKGROUND

Antidepressants are among the most frequently prescribed medications during pregnancy and may affect fetal weight. Associations between antenatal antidepressant use and ultrasonographic measures of fetal development have rarely been examined. We hypothesized that the prescription of an antenatal antidepressant would be associated with lower estimated fetal weight (EFW).

METHODS/PROCEDURES

A retrospective analysis of routine ultrasonographic data extracted from electronic medical records was performed on a cohort of pregnant women with psychiatric diagnoses and grouped according to the presence of an antenatal antidepressant prescription (n = 32 antidepressant-prescribed and n = 44 antidepressant prescription-free). After stratifying for gestational age, comparisons included 13 ultrasonographic parameters, frequency of oligohydramnios and polyhydramnios and growth deceleration, and maternal serum protein markers assessed per routine care, including α-fetoprotein, free β-human chorionic gonadotropin, and unconjugated estriol levels, using t tests, nonparametric and Fisher tests, and effect sizes (ESs) were computed.

FINDINGS/RESULTS

No statistically significant EFW differences between groups at any time point were detected (P > 0.05). Antenatal antidepressant prescription was associated with lower femur length at weeks 33 to 40 (P = 0.046, ES = 0.75) and greater left ventricular diameter at weeks 25 to 32 (P = 0.04, ES = 1.18). No differences for frequency of oligohydramnios or polyhydramnios or growth deceleration were observed (P > 0.05). We did not detect group differences for maternal proteins (P > 0.05).

IMPLICATIONS/CONCLUSIONS

Our evidence suggested a lack of association between antenatal antidepressant prescription and lower EFW but indicated an association with lower femur length and greater left ventricular diameter in mid-late gestation. Future research should examine the clinical implications of these findings.

Environmental levels of venlafaxine impact larval behavioural performance in fathead minnows

Venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor, is one of the most abundant antidepressants in municipal wastewater effluents (MWWE). The early life stages are particularly sensitive to contaminant exposure, but few studies have examined whether persistent exposure to venlafaxine impart adverse developmental outcomes. The fathead minnow (Pimephales promelas) is a widely used model for ecotoxicological studies, and this fish is native to Alberta, Canada. We tested the hypothesis that environmental levels of venlafaxine compromises early developmental behavioural performances in fathead minnows. Embryos were exposed to waterborne venlafaxine at either 0, 0.06, 0.33, 0.66, 1.37 or 3 μg L^-1 concentration for 7 days. Environmental levels of venlafaxine did not impact the survival, hatch rate or heart rate of fathead minnow embryos and larvae but reduced the growth of larvae even at concentrations as low as 0.06 μg L^-1. We validated thigmotaxis as a screen for anxiolytic and anxiogenic behaviour in fathead minnow larvae by exposing them to concentrations of ethanol and caffeine, respectively. Behavioural analyses revealed that early developmental exposure to venlafaxine does not alter thigmotaxis but reduced the activity of fathead minnows. The larval behavioural assays reported here for fathead minnow have the potential to be used as screening tools for the risk assessment of neurotoxic contaminants in MWWE. Overall, we demonstrate for the first time that exposure to environmental levels of venlafaxine during the critical early developmental window does not elicit an anxiogenic response but may adversely affect the larval growth performance of fathead minnows.

Hub distribution of the brain functional networks of newborns prenatally exposed to maternal depression and SSRI antidepressants

BACKGROUND

Prenatal maternal depression (PMD) and selective serotonin reuptake inhibitor (SSRI) antidepressants are associated with increased developmental risk in infants. Reports suggest that PMD is associated with hyperconnectivity of the insula and the amygdala, while SSRI exposure is associated with hyperconnectivity of the auditory network in the infant brain. However, associations between functional brain organization and PMD and/or SSRI exposure are not well understood.

METHODS

We examined the relation between PMD or SSRI exposure and neonatal brain functional organization. Infants of control (n = 17), depressed SSRI-treated (n = 20) and depressed-only (HAM-D ≥ 8) (n = 16) women, underwent resting-state functional magnetic resonance imaging at postnatal Day 6. At 6 months, temperament was assessed using Infant Behavioral Questionnaire (IBQ). We applied GTA and partial least square regression (PLSR) to the resting-state time series to assess group differences in modularity, and connector and provincial hubs.

RESULTS

Modularity was similar across all groups. The depressed-only group showed higher connector hub values in the left anterior cingulate, insula, and caudate as well as higher provincial hub values in the amygdala compared to the control group. The SSRI group showed higher provincial hub values in Heschl's gyrus relative to the depressed-only group. PLSR showed that newborns' hub values predicted 10% of the variability in infant temperament at 6 months, suggesting different developmental patterns between groups.

CONCLUSIONS

Prenatal exposures to maternal depression and SSRIs have differential impacts on neonatal functional brain organization. Hub values at 6 days predict variance in temperament between infant groups at 6 months of age.

Postnatal outcomes in lambs exposed antenatally and acutely postnatally to fluoxetine

BACKGROUND

Approximately 1/3 of newborns exposed antenatally to selective serotonin reuptake inhibitors (SSRIs) exhibit poor neonatal adaptation. Although several potential mechanisms have been proposed, the actual mechanism has not been elucidated.

METHODS

We investigated outcomes in neonatal lambs exposed prenatally or postnatally to fluoxetine (FX). Daily FX injections (50 mg) were given intravenously (i.v.) to five pregnant ewes via implanted catheters beginning at 131-132 days gestation (term = 147 days) for 2 weeks. In another group, lambs with implanted vascular catheters had sterile water (n = 9) or FX (1 mg/kg, n = 12) injected i.v. on ~postnatal day (PND) 4.

RESULTS

Prenatal FX-exposed lambs (n = 7) were hyperactive during PND 4 to 14 and their heart rate variability (HRV) was significantly lower than in control lambs (n = 7) on PND 2. In contrast, arterial pressure, heart rate, electrocardiogram, arterial blood gases, pH, glucose, lactate, cortisol, and sleep-activity cycles were not altered following postnatal FX injection.

CONCLUSION

This abnormal postnatal hyperactivity with antenatal FX exposure may reflect increased maturity in terms of locomotory activity. The results suggest that altered brain development may be involved in the poor neonatal adaptation in human infants exposed to FX in utero.

In utero and lactational exposure to the Selective Serotonin Reuptake Inhibitor fluoxetine compromises pup bones at weaning

Selective Serotonin Reuptake Inhibitors (SSRIs) such as fluoxetine are widely prescribed to pregnant and breastfeeding women, yet the effects of peripartum SSRI exposure on neonatal bone are not known. In adult populations, SSRI use is associated with compromised bone health, and infants exposed to in utero SSRIs have a smaller head circumference and are shorter, suggesting possible effects on longitudinal growth. Yet no study to date has examined the effects of peripartum SSRIs on long bone growth or mass. We used microCT to determine the outcomes of in utero and lactational SSRI exposure on C57BL6 pup bone microarchitecture. We found that peripartum exposure to 20 mg/kg fluoxetine reduced femoral bone mineral density and bone volume fraction, negatively impacted trabecular and cortical parameters, and resulted in shorter femurs on postnatal day 21. Although SSRIs are considered the first-choice antidepressant for pregnant and lactating women due to a low side effect profile, SSRI exposure may compromise fetal and neonatal bone development.

A Prospective Study Evaluating the Effects of SSRI Exposure on Cardiac Size and Function in Newborns

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are antidepressants prescribed in 10% of pregnancies in the USA. We have previously shown in preclinical studies that sertraline exposure impacts cardiomyocyte development, leading to reductions in left ventricular size and cardiac function.

OBJECTIVES

We hypothesized that in utero SSRI exposure will lead to reduced left ventricular dimensions and cardiac function on echocardiography immediately after birth.

METHODS

Twenty term infants with and 21 term infants without in utero exposure to SSRIs underwent echocardiograms to assess cardiac size and function. The exclusion criteria for infants were prematurity, small or large for gestational age, any respiratory or cardiovascular support needed after birth, and any major congenital malformation.

RESULTS

Infants exposed to in utero SSRIs had significantly reduced right ventricular dimensions in the diastole (controls 1.0 cm [0.86, 1.20], SSRI 0.89 cm [0.730, 1.05], p = 0.03), and left ventricular lengths in the diastole and systole (diastole: controls 3.4 cm [3.25, 3.65], SSRI 3.25 cm [3.10, 3.45], p = 0.03; systole: controls 2.9 cm [2.65, 3.05], SSRI 2.6 cm [2.50, 2.85], p = 0.01). No differences were observed in cardiac function. Importantly, there were no differences in maternal conditions or infant birth weight, body surface area, or gestational age.

CONCLUSIONS

Our findings suggest an association between in utero exposure to SSRIs and ventricular size in infants. Given the increasing use of SSRIs during pregnancy and the importance of early life programming on future cardiovascular health, larger studies need to be completed to determine if in utero SSRI exposure impacts ventricular size.

Transgenerational hypocortisolism and behavioral disruption are induced by the antidepressant fluoxetine in male zebrafish Danio rerio

The global prevalence of depression is high during childbearing. Due to the associated risks to the mother and baby, the selective serotonin reuptake inhibitor fluoxetine (FLX) is often the first line of treatment. Given that FLX readily crosses the placenta, a fetus may be susceptible to the disruptive effects of FLX during this highly plastic stage of development. Here, we demonstrate that a 6-day FLX exposure to a fetus-relevant concentration at a critical developmental stage suppresses cortisol levels in the adult zebrafish (F₀). This effect persists for three consecutive generations in the unexposed descendants (F₁ to F₃) without diminution and is more pronounced in males. We also show that the in vivo cortisol response of the interrenal (fish "adrenal") to an i.p. injection of adrenocorticotropic hormone was also reduced in the males from the F₀ and F₃ FLX lineages. Transcriptomic profiling of the whole kidney containing the interrenal cells revealed that early FLX exposure significantly modified numerous pathways closely associated with cortisol synthesis in the male adults from the F₀ and F₃ generations. We also show that the low cortisol levels are linked to significantly reduced exploratory behaviors in adult males from the F₀ to F₂ FLX lineages. This may be a cause for concern given the high prescription rates of FLX to pregnant women and the potential long-term negative impacts on humans exposed to these therapeutic drugs.

Selective Serotonin Reuptake Inhibitors Reduce Longitudinal Growth in Risperidone-Treated Boys

OBJECTIVES

To examine whether selective serotonin reuptake inhibitors (SSRIs) inhibit longitudinal growth in children and adolescents, particularly in the early stages of puberty, using a sample of convenience comprising risperidone-treated boys.

STUDY DESIGN

Data from four clinic-based studies in risperidone-treated 5- to 17-year-old boys with no general medical conditions were combined for this analysis. Anthropometric measurements and psychotropic treatment history were extracted from the medical and pharmacy records. Linear mixed effects regression analyses examined the association between SSRI use and change in age-sex-specific height and body mass index z scores, after adjusting for relevant confounders.

RESULTS

Risperidone-treated boys (n = 267; age: 12.7 ± 2.7 years), 71% of whom had ever taken an SSRI, contributed to the analysis. After adjusting for age, psychostimulant and antipsychotic use, and time in the study, both the duration of SSRI use as well as the cumulative dose were inversely associated with height z score after age 11 years (P < .0001). After adjusting for baseline height, duration of SSRI use was most strongly inversely associated with height z score in Tanner stages 3 and 4 boys who took SSRIs continuously (r = -0.69, P < .009). No association was observed with body mass index z score.

CONCLUSIONS

In risperidone-treated boys, SSRI use is associated with reduced longitudinal growth, particularly in those undergoing puberty. Whether adult height or other metabolic or psychological outcomes are affected remains to be determined.

Alterations in Resting-State Networks Following In Utero Selective Serotonin Reuptake Inhibitor Exposure in the Neonatal Brain

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat depression during pregnancy. SSRIs cross the placenta, inhibit serotonin reuptake, and thereby are thought to alter central fetal serotonin signaling. Both prenatal maternal mood disturbances and in utero SSRI exposure have been associated with altered fetal and infant behavior. Resting-state functional magnetic resonance imaging has identified resting-state networks (RSNs) in newborns, reflecting functional capacity of auditory and visual networks and providing opportunities to examine early experiences effects on neurodevelopment. We sought to examine the effect of in utero SSRI exposure on neonatal RSN functional organization. We hypothesized that prenatal SSRI exposure would be associated with alterations in neonatal RSNs compared with healthy control infants and infants exposed to mothers with depression.

METHODS

Clinician-rated Hamilton Depression Rating Scale and self-reported Pregnancy Experiences Scale were completed during the third trimester. Control (n = 17), maternal depression-exposed (Hamilton Depression Rating Scale ≥8 without SSRI exposure, n = 16), and SSRI-exposed (n = 20) 6-day-old neonates underwent resting-state functional magnetic resonance imaging. Independent component analysis was used as a data-driven approach to extract 22 RSNs.

RESULTS

SSRI-exposed neonates had higher connectivity in a putative auditory RSN compared with depressed-only (p = .01) and control (p = .02) infants (corrected for multiple comparisons), controlling for sex, age at the magnetic resonance imaging, and Pregnancy Experiences Scale score.

CONCLUSIONS

Hyperconnectivity in auditory RSN in neonates with in utero SSRI exposure relative to neonates of depressed but not pharmacologically treated mothers and control infants may offer an insight into the functional organization origins of shifts in language perception and altered language development, previously reported in infants and children with prenatal SSRI exposure.

Prenatal fluoxetine modifies the behavioral and hormonal responses to stress in male mice: role for glucocorticoid insensitivity

Women with major depressive disorder during pregnancy often use selective serotonin reuptake inhibitors (SSRIs) antidepressants. These drugs readily cross the placental barrier and impact the developing fetal brain. Recently, we reported that prenatal fluoxetine (FLX), an SSRI antidepressant drug, altered corticosterone and behavioral responses to stress in female mouse offspring. The present study assessed the effects of prenatal FLX on these responses in males. The results showed that prenatal FLX significantly augmented the corticosterone response to acute stress in young prepubescent mice. The corticosterone response to continuous stress was not affected by prenatal FLX irrespective of age. In addition, continuous stress reduced general activity, and anxiety-like and depressive-like behaviors in adult animals prenatally exposed to FLX, but not in controls. The dexamethasone suppression test showed that prenatal FLX induced a state of glucocorticoid insensitivity in adult males, indicating that the negative feedback control of the hypothalamic-pituitary-adrenal axis response to stress was disrupted. Together, these findings indicate that prenatal FLX altered hormonal and behavioral responses to stress and suggest a role for the development of glucocorticoid insensitivity in these effects. These findings may aid understanding of the limitations and precautions that should be taken in the use of SSRIs by pregnant women.

Perinatal fluoxetine effects on social play, the HPA system, and hippocampal plasticity in pre-adolescent male and female rats: Interactions with pre-gestational maternal stress

Selective serotonin reuptake inhibitor medications (SSRIs) are the first lines of treatment for maternal affective disorders, and are prescribed to up to 10% of pregnant women. Concern has been raised about how perinatal exposure to these medications affect offspring neurobehavioral outcomes, particularly those related to social interactions, as recent research has reported conflicting results related to autism spectrum disorder (ASD) risk in children prenatally exposed to SSRIs. Therefore, the aim of this work was to investigate the effects of perinatal exposure to the SSRI fluoxetine on social play behaviors and the hypothalamic pituitary adrenal system, using a model of pre-gestational maternal stress. We also investigated synaptic proteins in the CA2, CA3, and dentate gyrus of the hippocampus, as well as number of immature neurons in the granule cell layer, as both measures of plasticity in the hippocampus have been linked to social behaviors. In pre-adolescent male and female Sprague-Dawley rat offspring, main findings show that perinatal fluoxetine prevents the negative effect of maternal stress on sibling play behavior. However, perinatal fluoxetine increased social aggressive play with a novel conspecific in both sexes and decreased time grooming a novel conspecific in males only. Perinatal fluoxetine also increased serum corticosteroid binding globulin levels, 5-HT levels in the hippocampus, and pre-synaptic density assessed via synaptophysin in the dentate gyrus. Social interaction was significantly correlated with changes in plasticity in the CA2 region of the hippocampus. Pre-gestational maternal stress exposure resulted in significantly decreased rates of hippocampal neurogenesis and synaptophysin density in the dentate gyrus of pre-adolescent males, but not females. Together, these results further characterize the role of perinatal SSRIs, maternal stress prior to conception, and sex/gender on developing social behaviors and related plasticity in the hippocampus of pre-adolescent offspring.

The effects of maternal antidepressant use on offspring behaviour and brain development: Implications for risk of neurodevelopmental disorders

Approximately 10% of pregnant women are prescribed antidepressant drugs (ADDs), with selective serotonin reuptake inhibitors (SSRIs) the most widely prescribed. SSRIs bind to the serotonin transporter (SERT), blocking the reabsorption of serotonin by the presynaptic neuron and increasing serotonin levels in the synaptic cleft. The serotonergic system regulates a range of brain development processes including neuronal proliferation, migration, differentiation and synaptogenesis. Given the presence of SERT in early brain development, coupled with the ability of SSRIs to cross the placenta and also enter breast milk, concerns have been raised regarding the effects of SSRI exposure on the developing foetus and newborns. In this review, we evaluate preclinical and clinical studies that have examined the effects of maternal SSRI exposure and the risk for altered neurodevelopment and associated behaviours in offspring. While the current body of evidence suggests that maternal SSRI treatment may cause perturbations to the neurobiology, behaviour and ultimately risk for neurodevelopmental disorders in exposed offspring, conflicting findings do exist and the evidence is not conclusive. However, given the increasing incidence of depression and number of women prescribed ADDs during pregnancy, further investigation into this area is warranted.

Serotonin and poor neonatal adaptation after antidepressant exposure in utero

OBJECTIVE

Infants exposed to selective antidepressants (SADs) in utero are at risk to develop poor neonatal adaptation (PNA) postpartum. As symptoms are non-specific and the aetiology of PNA is unknown, the diagnostic process is hampered. We hypothesised that the serotonin metabolism plays a role in the aetiology of PNA.

METHODS

In this controlled study, infants admitted postpartum from February 2012 to August 2013 were included and followed for 3 days. Infants exposed to SADs during at least the last 2 weeks of fetal life were included in the patient group (n=63). Infants not exposed to psychotropic medication and admitted postpartum for another reason were included in the control group (n=126). The neonatal urinary 5-hydroxyindoleacetid acid (5-HIAA) levels of SAD-exposed infants who developed PNA, SAD-exposed infants who did not develop PNA and control infants were compared.

RESULTS

The course of the 5-HIAA levels over the first 3 days postpartum differed between infants with and without PNA (p≤0.001) with higher 5-HIAA levels in infants with PNA on day 1 (2.42 mmol/mol, p=0.001). Presence of maternal psychological distress modified this relationship.

CONCLUSIONS

A transient disturbance of the neonatal serotonergic system may play a role in the aetiology of PNA. Other factors, including the presence of maternal psychological distress, also seem to play a role.

Prenatal SSRI alters the hormonal and behavioral responses to stress in female mice: Possible role for glucocorticoid resistance

Life time prevalence of major depression disorder (MDD) is higher in women compared to men especially during the period surrounding childbirth. Women suffering from MDD during pregnancy use antidepressant medications, particularly Selective Serotonin Reuptake Inhibitors (SSRI). These drugs readily cross the placental barrier and impact the developing fetal brain. The present study assessed the effects of prenatal exposure to fluoxetine (FLX), an SSRI antidepressant drug, on corticosterone and behavioral responses to stress in female mice. In young females, prenatal FLX significantly elevated corticosterone response to continuous stress. In adults, prenatal FLX augmented corticosterone response to acute stress and suppressed the response to continuous stress. Additionally, prenatal FLX significantly augmented stress-induced increase in locomotion and reduced anxiety- and depressive-like behaviors in adult, but not young mice. The dexamethasone suppression test revealed that prenatal FLX induced a state of glucocorticoid resistance in adult females, indicating that the negative feedback control of the hypothalamic-pituitary-adrenal axis response to stress was disrupted. These findings provide the first indication of altered hormonal and behavioral responses to continuous stress and suggest a role for the development of glucocorticoid resistance in these effects. According to these findings, prenatal environment may have implications for stress sensitivity and responsiveness to life challenges. Furthermore, this study may assist in understanding the limitations and precautions that should be taken in the use of SSRIs during pregnancy.

Is poor neonatal adaptation after exposure to antidepressant medication related to fetal cortisol levels? An explorative study

BACKGROUND

As a marker for poor neonatal adaptation (PNA) is lacking, the diagnostic process is difficult and includes invasive additional testing.

AIMS

In order to develop a marker, it is essential to gain insight into the etiology of PNA. We hypothesized that the fetal cortisol level may play a role in this etiology.

STUDY DESIGN

Non-randomized, prospective controlled study.

OUTCOME MEASURES

We examined hair cortisol levels of infants exposed and not exposed to selective antidepressants (SADs) during pregnancy. These cortisol levels represent the mean cortisol level during the last trimester of pregnancy. Infants exposed to SADs who developed PNA according to the pediatrician (PNA+, n=25), infants exposed to SADs who did not develop PNA (PNA-, n=40) and infants not exposed to SADs (controls, n=105) were compared.

RESULTS

In infants with PNA, hair cortisol levels were higher compared to infants without PNA. However this difference was only statistically significant in female infants (girls B0.33, p=0.04, boys B0.05, p=0.82). There was no correlation between nonspecific distress, measured by the Finnegan score and fetal hair cortisol levels (B-0.15, p=0.30). All analyses were adjusted for type of delivery and gestational age.

CONCLUSIONS

Our results suggest that the hypothalamic pituitary adrenal (HPA) axis activity may play a sex-specific role in the development of PNA. As PNA is most likely of a multifactorial origin, it would be interesting to examine other factors possibly involved in the etiology of PNA in future studies, such as (epi) genetics.

Citalopram and sertraline exposure compromises embryonic bone development

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed treatments for depression and, as a class of drugs, are among the most used medications in the world. Concern regarding possible effects of SSRI treatment on fetal development has arisen recently as studies have suggested a link between maternal SSRI use and an increase in birth defects such as persistent pulmonary hypertension, seizures and craniosynostosis. Furthermore, SSRI exposure in adults is associated with decreased bone mineral density and increased fracture risk, and serotonin receptors are expressed in human osteoblasts and osteoclasts. To determine possible effects of SSRI exposure on developing bone, we treated both zebrafish, during embryonic development, and human mesenchymal stem cells (MSCs), during differentiation into osteoblasts, with the two most prescribed SSRIs, citalopram and sertraline. SSRI treatment in zebrafish decreased bone mineralization, visualized by alizarin red staining and decreased the expression of mature osteoblast-specific markers during embryogenesis. Furthermore, we showed that this inhibition was not associated with increased apoptosis. In differentiating human MSCs, we observed a decrease in osteoblast activity that was associated with a decrease in expression of the osteoblast-specific genes Runx2, Sparc and Spp1, measured with quantitative real-time PCR (qRT-PCR). Similar to the developing zebrafish, no increase in expression of the apoptotic marker Caspase 3 was observed. Therefore, we propose that SSRIs inhibit bone development by affecting osteoblast maturation during embryonic development and MSC differentiation. These results highlight the need to further investigate the risks of SSRI use during pregnancy in exposing unborn babies to potential skeletal abnormalities.

Fetal Exposure to Sertraline Hydrochloride Impairs Pancreatic β-Cell Development

Ten percent to 15% of women take selective serotonin reuptake inhibitor (SSRI) antidepressants during pregnancy. Offspring exposed to SSRIs are more likely to have low birth weight; this is associated with an increased risk of development of diabetes in adulthood in part due to altered pancreatic development. The effects of perinatal exposure to SSRIs on pancreatic development are unknown. Therefore, the objective of this study was to determine the effect of fetal exposure to sertraline hydrochloride on pregnancy outcomes and pancreatic development. Wistar rats were given vehicle (n = 5) or sertraline hydrochloride (10 mg/kg/d; n = 8) via daily subcutaneous injection from the confirmation of mating until parturition. Results from this animal model demonstrated that offspring born to sertraline-exposed dams have no changes in birth weight but had a reduction in pancreatic β-cell area. The altered pancreatic islet development was a result of altered gene expression regulating islet development and survival. Therefore, fetal exposure to sertraline reduces β-cell capacity at birth, raising concerns regarding the long-term metabolic sequelae of such exposures.

Developmental exposure to SSRIs, in addition to maternal stress, has long-term sex-dependent effects on hippocampal plasticity

RATIONALE

During pregnancy and postpartum period, 20 % of women are affected by depression, which is a growing health concern. Selective serotonin reuptake inhibitor (SSRI) medications are popular treatments for maternal depression; however, the effect of maternal depression and perinatal SSRI exposure on offspring's neural development needs further investigation.

OBJECTIVES

This study aims to determine the role of developmental fluoxetine exposure on hippocampal plasticity in the adult offspring.

METHODS

Sprague-Dawley rat offspring were exposed to fluoxetine beginning on postnatal day 1. Offspring were also exposed to prenatal maternal stress. Four groups of male and female offspring were used: (1) prenatal stress + fluoxetine, (2) prenatal stress + vehicle, (3) fluoxetine alone, and (4) vehicle alone. Hippocampi were analyzed for levels of cell proliferation, immature neurons, and new cell survival (3 weeks after 5-bromo-2-deoxyuridine injection) in the granule cell layer, as well as synaptophysin density in the CA3 region and granule cell layer. TPH staining was assessed in the dorsal raphe nucleus.

RESULTS

Developmental fluoxetine exposure to prenatally stressed offspring reversed the effect of prenatal stress or fluoxetine exposure alone on the number of immature neurons. Prenatal stress alone, regardless of developmental exposure to fluoxetine, markedly decreased hippocampal cell proliferation and tended to decrease new cell survival. Furthermore, in adult female offspring, developmental fluoxetine exposure greatly increased new cell survival and significantly decreased synaptophysin density in the granule cell layer.

CONCLUSIONS

There are long-term effects of developmental SSRI exposure on hippocampal plasticity that is differentially affected by expose to maternal adversity and offspring sex.

Maternal use of antidepressant or anxiolytic medication during pregnancy and childhood neurodevelopmental outcomes: a systematic review

Antidepressant and anxiolytic medications are widely prescribed and used by pregnant women for acute and maintenance therapy. These drugs are able to pass the placental barrier, and may potentially influence fetal and brain development. It is possible that exposure to prenatal antidepressants or anxiolytic medication may disturb neurotransmitter systems in the brain and have long-lasting consequences on neurodevelopment in the offspring. As all medication during pregnancy may pose a certain risk to the developing fetus, the potential benefits of the medication must be weighed against the risks for both mother and her unborn child. Therefore, information to guide patients and physicians to make a well-balanced decision for the appropriate treatment during pregnancy is needed. In this systematic review, an overview of maternal use of antidepressant or anxiolytic medication during pregnancy and childhood neurodevelopmental outcomes is provided. Some studies indicate a relation between prenatal exposure to antidepressants and adverse neurodevelopmental outcomes such as delayed motor development/motor control, social difficulties, internalizing problems and autism, but cannot rule out confounding by indication. Overall, the results of the observational studies have been inconsistent, which makes translation of the findings into clinical recommendations difficult. More well-designed observational studies and also randomized controlled trials (e.g., maintenance treatment vs. cessation) are needed to move forward and provide a comprehensive evaluation of the risks and benefits of antidepressant and anxiolytic use during pregnancy.

Fluoxetine induces proliferation and inhibits differentiation of hypothalamic neuroprogenitor cells in vitro

A significant number of children undergo maternal exposure to antidepressants and they often present low birth weight. Therefore, it is important to understand how selective serotonin reuptake inhibitors (SSRIs) affect the development of the hypothalamus, the key center for metabolism regulation. In this study we investigated the proliferative actions of fluoxetine in fetal hypothalamic neuroprogenitor cells and demonstrate that fluoxetine induces the proliferation of these cells, as shown by increased neurospheres size and number of proliferative cells (Ki-67⁺ cells). Moreover, fluoxetine inhibits the differentiation of hypothalamic neuroprogenitor cells, as demonstrated by decreased number of mature neurons (Neu-N⁺ cells) and increased number of undifferentiated cells (SOX-2⁺ cells). Additionally, fluoxetine-induced proliferation and maintenance of hypothalamic neuroprogenitor cells leads to changes in the mRNA levels of appetite regulator neuropeptides, including Neuropeptide Y (NPY) and Cocaine-and-Amphetamine-Regulated-Transcript (CART). This study provides the first evidence that SSRIs affect the development of hypothalamic neuroprogenitor cells in vitro with consequent alterations on appetite neuropeptides.

Prenatal antidepressant exposure: clinical and preclinical findings

Pharmacological treatment of any maternal illness during pregnancy warrants consideration of the consequences of the illness and/or medication for both the mother and unborn child. In the case of major depressive disorder, which affects up to 10-20% of pregnant women, the deleterious effects of untreated depression on the offspring can be profound and long lasting. Progress has been made in our understanding of the mechanism(s) of action of antidepressants, fetal exposure to these medications, and serotonin's role in development. New technologies and careful study designs have enabled the accurate sampling of maternal serum, breast milk, umbilical cord serum, and infant serum psychotropic medication concentrations to characterize the magnitude of placental transfer and exposure through human breast milk. Despite this progress, the extant clinical literature is largely composed of case series, population-based patient registry data that are reliant on nonobjective means and retrospective recall to determine both medication and maternal depression exposure, and limited inclusion of suitable control groups for maternal depression. Conclusions drawn from such studies often fail to incorporate embryology/neurotransmitter ontogeny, appropriate gestational windows, or a critical discussion of statistically versus clinically significant. Similarly, preclinical studies have predominantly relied on dosing models, leading to exposures that may not be clinically relevant. The elucidation of a defined teratological effect or mechanism, if any, has yet to be conclusively demonstrated. The extant literature indicates that, in many cases, the benefits of antidepressant use during pregnancy for a depressed pregnant woman may outweigh potential risks.

Central nervous system effects of prenatal selective serotonin reuptake inhibitors: sensing the signal through the noise

RATIONALE

Women are increasingly prescribed selective serotonin reuptake inhibitors (SSRIs) during pregnancy, with potential implications for neurodevelopment. Whether prenatal SSRI exposure has an effect on neurodevelopment and behavior in the offspring is an important area of investigation.

OBJECTIVES

The aim of this paper was to review the existing preclinical and clinical literature of prenatal SSRI exposure on serotonin-related behaviors and markers in the offspring. The goal is to determine if there is a signal in the literature that could guide clinical care and/or inform research.

RESULTS

Preclinical studies (n = 4) showed SSRI exposure during development enhanced depression-like behavior. Half of rodent studies examining anxiety-like behavior (n = 13) noted adverse effects with SSRI exposure. A majority of studies of social behavior (n = 4) noted a decrease in sociability in SSRI exposed offspring. Human studies (n = 4) examining anxiety in the offspring showed no adverse effects of prenatal SSRI exposure. The outcome of one study suggested that children with autism were more likely to have a mother who was prescribed an SSRI during pregnancy.

CONCLUSIONS

Preclinical findings in rodents exposed to SSRIs during development point to an increase in depression- and anxiety-like behavior and alteration in social behaviors in the offspring, though both the methods used and the findings were not uniform. These data are not robust enough to discourage use of SSRIs during human pregnancy, particularly given the known adverse effects of maternal mental illness on pregnancy outcomes and infant neurodevelopment. Future research should focus on consistent animal models and prospective human studies with larger samples.

Does fetal exposure to SSRIs or maternal depression impact infant growth?

OBJECTIVE

The aim of this study was to compare the growth of infants born to women with antenatal major depressive disorder, either untreated or treated with selective serotonin reuptake inhibitor (SSRI) antidepressants, and infants born to a nondepressed, nonmedicated comparison group across the first year of life.

METHOD

In this prospective observational study, pregnant women were evaluated at weeks 20, 30, and 36 of gestation, and mother and infant pairs were assessed at 2, 12, 26, and 52 weeks postpartum. Three nonoverlapping groups of women were defined according to their pregnancy exposures: 1) no SSRI and no depression (N=97), 2) SSRI (N=46), and 3) major depression without SSRI (N=31). Maternal demographic and clinical characteristics and newborn outcomes were compared across exposure groups. Infant weight, length, and head circumference were measured by a physician or physician's assistant who was blind to depression and SSRI exposure status at each postpartum time point.

RESULTS

Both adjusted and unadjusted analyses revealed neither antenatal major depression nor SSRI exposure was significantly associated with infant weight, length, or head circumference relative to nonexposure to either. In addition, the interaction of group and prepregnancy body mass index was also evaluated, and no significant synergistic effect was identified. Similarly, no differential effect of group over time was observed for weight, length, or head circumference.

CONCLUSIONS

In utero exposure to major depression or SSRI antidepressants did not affect infant growth with respect to weight, length, or head circumference from birth through 12 months of age.

Developmental exposure to fluoxetine modulates the serotonin system in hypothalamus

The selective serotonin reuptake inhibitor (SSRI) fluoxetine (FLU, Prozac®) is commonly prescribed for depression in pregnant women. This results in SSRI exposure of the developing fetus. However, there are knowledge gaps regarding the impact of SSRI exposure during development. Given the role of serotonin in brain development and its cross-talk with sex hormone function, we investigated effects of developmental exposure to pharmacologically relevant concentrations of FLU (3 and 30 nM (measured)) on brain neurotransmitter levels, gonadal differentiation, aromatase activity in brain and gonads, and the thyroid system, using the Xenopus tropicalis model. Tadpoles were chronically exposed (8 weeks) until metamorphosis. At metamorphosis brains were cryosectioned and levels of serotonin, dopamine, norepinephrine, and their metabolites 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic acid, and homovanillic acid were measured in discrete regions (telencephalon, hypothalamus and the reticular formation) of the cryosections using high-performance liquid chromatography. Exposure to 30 nM FLU increased the concentration of 5-hydroxyindoleacetic acid in hypothalamus compared with controls. FLU exposure did not affect survival, time to metamorphosis, thyroid histology, gonadal sex differentiation, or aromatase activity implying that the effect on the serotonergic neurotransmitter system in the hypothalamus region was specific. The FLU concentration that impacted the serotonin system is lower than the concentration measured in umbilical cord serum, suggesting that the serotonin system of the developing brain is highly sensitive to in utero exposure to FLU. To our knowledge this is the first study showing effects of developmental FLU exposure on brain neurochemistry. Given that SSRIs are present in the aquatic environment the current results warrant further investigation into the neurobehavioral effects of SSRIs in aquatic wildlife.

Mechanism of earthquake simulation as a prenatal stressor retarding rat offspring development and chinese medicine correcting the retardation: hormones and gene-expression alteration

We aimed to investigate the mechanism of shaking as a prenatal stressor impacting the development of the offspring and Chinese medicines correcting the alterations. Pregnant rats were randomized into earthquake simulation group (ESG), herbal group (HG) which received herbal supplements in feed after shaking, and control group (CG). Findings revealed body weight and open field test (OFT) score of ESG offspring were statistically inferior to the CG and HG offspring. The corticosterone levels of ESG were higher than those of CG but not than HG. The dopamine level of ESG was slightly lower than that of the CG and of HG was higher than that of ESG. The 5-HT of ESG was higher than CG and HG. The growth hormone level of the ESG was significantly lower than ESG but not than CG. Gene expression profile showed 81 genes upregulated and 39 genes downregulated in ESG versus CG, and 60 genes upregulated and 28 genes downregulated in ESG versus HG. Eighty-four genes were found differentially expressed in ESG versus CG comparison and were normalized in ESG versus HG. We conclude that maternal shaking negatively affected physical and nervous system development, with specific alterations in neurohormones and gene expression. Chinese herbal medicine reduced these negative outcomes.

Fetal serotonin reuptake inhibitor antidepressant exposure: maternal and fetal factors

Prenatal serotonin reuptake inhibitor exposure is common and neonatal outcomes vary greatly, often leading to confusion about whether to use or even continue antenatal use of these antidepressants. Importantly, some but not all infants are affected, which raises questions about how maternal drug metabolism contributes to fetal drug exposure. To address this key question, our paper reviews the role of key maternal, fetal, and placental pharmacokinetic, metabolic, and genetic factors that affect the extent of fetal drug exposure. Considering the role of these factors may further our understanding of variables that may assist in optimizing maternal psychopharmacotherapy during pregnancy and neonatal outcomes.

Fetal serotonin signaling: setting pathways for early childhood development and behavior

Finely tuning levels of the key neurotransmitter serotonin (5-hydroxytryptamine [5-HT]) during early life is essential for brain development and setting pathways for health and disorder across the early life span. Given the central role of 5-HT in brain development, regulation of mood, stress reactivity, and risk for psychiatric disorders, alterations in 5-HT signaling early in life have critical implications for behavior and mental health in childhood and adolescence. This article reviews the developmental consequences of two key influences that alter fetal 5-HT signaling: (1) in utero exposure to 5-HT reuptake inhibitor antidepressants, and (2) genetic variations in the 5-HT transporter gene (SLC6A4). The consequences of altered prenatal 5-HT signaling vary greatly, and developmental outcomes depend on an ongoing interplay between biological (genetic/epigenetic variations), experiential (prenatal drug or maternal mood exposure), and contextual (postnatal social environment) variables. Emerging evidence suggests both exposure to 5-HT reuptake inhibitors and genetic variations that affect 5-HT signaling may increase sensitivity to negative social contexts for some individuals, whereas for others, they may confer sensitivity to positive life circumstances. In this sense, factors that change central 5-HT levels may function less like influences that predict "vulnerability," but rather act like "plasticity factors." Understanding the impact of early changes in serotonergic programming offers critical insights that might explain patterns of individual differences in developmental risk and resilience.

Prenatal SSRI exposure alters neonatal corticosteroid binding globulin, infant cortisol levels, and emerging HPA function

BACKGROUND

Serotonin influences the development of the hypothalamic-pituitary-adrenal (HPA) system; therefore prenatal exposure to selective serotonin reuptake inhibitor antidepressants (SSRIs) may alter HPA axis development and function. To address this, prenatal exposure to SSRIs and maternal mood were examined in relation to neonatal and infant levels of cortisol and its binding protein, corticosteroid-binding globulin (CBG).

METHODS

Serum cortisol and CBG levels were assayed from SSRI-exposed and non-exposed mothers and their neonates at delivery. Maternal mood symptoms were documented at 36 weeks gestation. To determine the long-term implications of changes in CBG, levels of salivary cortisol were assessed in infants at 3 months of age.

RESULTS

Prenatal SSRI exposure significantly increased serum CBG levels in neonates after vaginal delivery (p ≤ 0.038), even when controlling for maternal depression. Neonatal serum cortisol levels did not vary with SSRI exposure or antenatal maternal mood, but were significantly higher following vaginal delivery (p ≤ 0.003). Neonatal serum CBG levels were associated with infant salivary levels of evening cortisol (p ≤ 0.051). In SSRI-exposed infants, increased levels of neonatal CBG predicted a smaller diurnal change in infant salivary cortisol (p ≤ 0.028), regardless of maternal depression.

CONCLUSIONS

Prenatal SSRI exposure affects the developing HPA system by altering serum CBG levels in neonates and infant salivary cortisol levels. Further research is warranted on the long-term functional implications of the effect of prenatal SSRI exposure on fetal hepatic CBG gene expression and the developing HPA system.

Neonatal SSRI Exposure Programs a Hypermetabolic State in Adult Mice

Background. Selective serotonin reuptake inhibitor (SSRI) therapy complicates up to 10% of pregnancies. During therapy, SSRIs exert pleiotropic antidepressant, anorexigenic, and neurotrophic effects. Intrauterine SSRI exposure has been modeled by neonatal administration to developmentally immature rodents, and it has paradoxically elicited features of adult depression. We hypothesized neonatal SSRI exposure likewise programs a rebound hypermetabolic state in adult mice. Methods. C57BL/6 pups were randomized to saline or sertraline (5 mg/kg/d) from P1–P14. Because estrogen increases tryptophan hydroxylase 2 (TPH2) expression, a subset of female mice underwent sham surgery or bilateral ovariectomy (OVX). Metabolic rate was determined by indirect calorimetry. Results. In both male and female mice, neonatal SSRI exposure increased adult caloric intake and metabolic rate. SSRI-exposed female mice had significantly decreased adult weight with a relative increase in brain weight and melatonin excretion, independent of ovarian status. Cerebral cortex TPH2 expression was increased in SSRI-exposed male mice but decreased in OVX SSRI-exposed female mice. Conclusions. SSRI exposure during a critical neurodevelopmental window increases adult caloric intake and metabolic rate. Ovarian status modulated central TPH2 expression, but not adult energy balance, suggesting programmed neural connectivity or enhanced melatonin production may play a more important role in the post-SSRI hypermetabolic syndrome.

Maternal use of selective serotonin reuptake inhibitors during pregnancy and neonatal bone density

BACKGROUND

Selective serotonin reuptake inhibitors (SSRI) are commonly used to treat depression in pregnant women. Several adverse effects of prenatal SSRI exposure on the offspring have been described, including decreased growth. SSRI use by adults decreases bone mineral density, but this effect had not been examined in infants.

AIM

To examine growth parameters and bone mineral density of infants born to mothers using SSRIs during pregnancy.

STUDY DESIGN

Anthropometric variables and bone density were compared between 40 newborns exposed to SSRIs in utero, and 40 gestational-age matched control infants. Tibial bone speed of sound, a marker of bone density and strength, was measured using quantitative ultrasound. The difference in bone speed of sound between the two groups was compared using linear models, adjusting for relevant confounders.

RESULTS

Infants in the SSRI-exposed group were shorter, with a marginal statistical significance (49.3±2.1 vs. 50.1±1.3cm, p=0.07), while mean birth weight did not differ substantially between study groups. Head circumference was significantly smaller in the SSRI group (33.8±1.2 vs 34.4±1.1cm, p=0.005), remaining so even after adjustment for several confounders. No considerable difference was found in the bone speed of sound between SSRI-exposed infants and controls (3011±116 vs. 3029±129m/s).

CONCLUSIONS

We found no evidence that prenatal SSRI exposure hindered neonatal bone quality, yet a marginally shorter length and a smaller head circumference raise the possibility of an effect on bone growth. We conclude that the effect of SSRIs on fetal bone density seems minimal or absent.