Impact of maternal prenatal smoking on fetal to infant neurobehavioral development

Pregnancy complications and childhood mental health: is the association modified by sex or adverse social circumstances? Findings from the 'growing up in Ireland' national infant cohort study

Specific pregnancy complications, socioeconomic position and sex have all been independently associated with child mental health outcomes, but their combined effects remain unclear. We examined whether total number of complications experienced in the pregnancy associated with mental health at 5 and 9-years, and whether this varied by sex or adverse social circumstances. Pregnancy complications were self-reported at 9-months post-natally from a list of 16 complications. Parents completed the Strengths and Difficulties Questionnaire (SDQ) when their child was 5 and 9-years. The primary outcome was the SDQ-total and scoring in the clinical range (> 16) was a secondary outcome. We applied generalized linear mixed models to a large nationally representative Irish cohort (GUI; n = 11,134). Analyses were adjusted for sex, adverse social circumstances (at 9-months), and gestational smoking. We included an interaction term between pregnancy complications and each variable respectively in separate models to examine if associations varied by sex or adverse circumstances.After controlling for covariates, total complications associated with mental health at 5 and 9-years. Each additional pregnancy complication conferred a 10% higher total-SDQ score (exponentiated co-efficient 1.10 [95%CI 1.06-1.14], 1.20 [1.15-1.26], 1.20 [1.12-1.29] and 1.34 [1.21-1.48] for 1, 2, 3 and 4 + complications respectively). For the dichotomised outcome, generally increasing odds for clinical levels of mental health difficulties were observed (OR 1complication = 1.89, 95%CI [1.37-2.59]; OR 2complications = 2.31, 95%CI [1.53-3.50]; OR 3complications = 1.77, 95%CI [0.89-3.52]; OR 4 + complications = 6.88, 95%CI [3.29-14.40]). Females had significantly lower odds of exhibiting clinically significant mental health difficulties than males (OR = 0.43, 95%CI[0.32-0.57]).There was no evidence that the association between pregnancy complications and child's mental health varied by sex or social circumstances at 5 or 9-years. Males exposed to numerous pregnancy complications in the context of adverse social circumstances had the highest predicted probability of having mental health difficulties in middle childhood.

Perceptions of family functioning impact smoking during pregnancy

BACKGROUND

Although socio-environmental factors are known to contribute to the maintenance of smoking behavior, few studies have examined the impact of family functioning on smoking during pregnancy.

OBJECTIVE

The current study examined the relationship between perceptions of family functioning and smoking during pregnancy.

METHODS

Pregnant women (N = 345, 59% ethnic/racial minority) completed the Family Assessment Device, a gold-standard assessment examining perceptions of family functioning in seven domains. Multinomial logistic regressions analyzed associations between clinically determined suboptimal levels of family functioning by domain and smoking status during pregnancy (smoking, ≥28 continuous days quit, nonsmoking), with stratified analyses exploring ethnic/racial differences (non-Hispanic/White vs. racial/ethnic minority).

RESULTS

Participants who reported suboptimal levels of family functioning in domains of Affective Involvement, Affective Responsiveness, Behavioral Control, and Roles were significantly more likely to have been smoking than nonsmoking during pregnancy. Stratified analyses revealed differing effects by ethnic/racial identity, with perceptions of Roles remaining the only significant effect on smoking outcomes for both groups. No significant effects were found regarding the impact of family functioning on whether participants were smoking vs. quit during pregnancy.

CONCLUSIONS

Suboptimal family functioning may contribute to smoking during pregnancy, but effects may differ based on domain of family functioning and by ethnic/racial identity.

Early developmental risks for tobacco addiction: A probabilistic epigenesis framework

Considerable progress has been made in elucidating the relationships between early life psychobiological and environmental risk factors and the development of tobacco addiction. However, a comprehensive understanding of the heterogeneity in tobacco addiction phenotypes requires integrating research findings. The probabilistic epigenesis meta-theory offers a valuable framework for this integration, considering systemic, multilevel, developmental, and evolutionary perspectives. In this paper, we critically review relevant research on early developmental risks associated with tobacco addiction and highlight the integrative heuristic value of the probabilistic epigenesis framework for this research. For this, we propose a four-level systems approach as an initial step towards integration, analyzing complex interactions among different levels of influence. Additionally, we explore a coaction approach to examine key interactions between early risk factors. Moreover, we introduce developmental pathways to understand interindividual differences in tobacco addiction risk during development. This integrative approach holds promise for advancing our understanding of tobacco addiction etiology and informing potentially effective intervention strategies.

Prenatal and perinatal factors associated with neonatal neurobehavioral profiles in the ECHO Program

BACKGROUND

Single-cohort studies have identified distinct neurobehavioral profiles that are associated with prenatal and neonatal factors based on the NICU Network Neurobehavioral Scale (NNNS). We examined socioeconomic, medical, and substance use variables as predictors of NNNS profiles in a multi-cohort study of preterm and term-born infants with different perinatal exposures.

METHODS

We studied 1112 infants with a neonatal NNNS exam from the Environmental influences on Child Health Outcomes (ECHO) consortium. We used latent profile analysis to characterize infant neurobehavioral profiles and generalized estimating equations to determine predictors of NNNS profiles.

RESULTS

Six distinct neonatal neurobehavioral profiles were identified, including two dysregulated profiles: a hypo-aroused profile (16%) characterized by lethargy, hypotonicity, and nonoptimal reflexes; and a hyper-aroused profile (6%) characterized by high arousal, excitability, and stress, with low regulation and poor movement quality. Infants in the hypo-aroused profile were more likely to be male, have younger mothers, and have mothers who were depressed prenatally. Infants in the hyper-aroused profile were more likely to be Hispanic/Latino and have mothers who were depressed or used tobacco prenatally.

CONCLUSIONS

We identified two dysregulated neurobehavioral profiles with distinct perinatal antecedents. Further understanding of their etiology could inform targeted interventions to promote positive developmental outcomes.

IMPACT

Prior research on predictors of neonatal neurobehavior have included single-cohort studies, which limits generalizability of findings. In a multi-cohort study of preterm and term-born infants, we found six distinct neonatal neurobehavioral profiles, with two profiles being identified as dysregulated. Hypo- and hyper-aroused neurobehavioral profiles had distinct perinatal antecedents. Understanding perinatal factors associated with dysregulated neurobehavior could help promote positive developmental outcomes.

Associations between prenatal exposure to second hand smoke and infant self-regulation in a New York city longitudinal prospective birth cohort

BACKGROUND

Prenatal exposure to active or passive maternal smoking -also referred to as second hand smoke (SHS) exposure - are associated with externalizing behaviors, hyperactivity and attention deficit hyperactivity disorder, problems which derive in part from altered self-regulation.

OBJECTIVES

Determine the influence of prenatal SHS on infant self-regulation using direct measures of infant behavior in 99 mothers from the Fair Start birth cohort followed at the Columbia Center for Children's Environmental Health.

METHODS

Self-regulation was operationalized with self-contingency, the likelihood of maintaining/changing behavior from second-to-second, measured via split-screen video recordings of mothers playing with their 4-month infants. Mother and infant facial and vocal affect, gaze-on/-off partner, and mother touch were coded on a 1 s time-base. Third trimester prenatal SHS was assessed via self-report of a smoker in the home. Weighted-lag time-series models tested conditional effects of SHS-exposure (vs. non-exposure) on infant self-contingency for eight modality-pairings (e.g., mother gaze-infant gaze). Individual-seconds time-series models and analysis of predicted values at t₀ interrogated significant weighted-lag findings. Because prior findings link developmental risk factors with lowered self-contingency, we hypothesized that prenatal SHSSHS would predict lowered infant self-contingency.

RESULTS

Relative to non-exposed infants, those who were prenatally exposed to SHS had lower self-contingency (more variable behavior) in all eight models. Follow-up analyses showed that, given infants were likely to be in the most negative facial or vocal affect, those with prenatal SHS were more likely to make larger behavioral changes, moving into less negative or more positive affect and to alternate between gaze-on and off mother. Mothers who were exposed to SHS during pregnancy (vs. non-exposed) showed a similar, albeit less prevalent, pattern of larger changes out of negative facial affect.

CONCLUSION

These findings extend prior work linking prenatal SHS with youth dysregulated behavior, showing similar effects in infancy, a critically important period that sthe stage for future child development.

Long-term impact of tobacco exposure during pregnancy on children's psychomotor development

BACKGROUND

Both active and second-hand smoking (SHS) can cause complications during pregnancy and after delivery. This study aimed to assess how tobacco exposure (active and passive) during the fetal period could impact the psychomotor development of children when they attain the age of 3-6 years.

METHODS

The study included 160 mothers and their 3-6 year-old children. Two research groups were set up of children born to active or SHS mothers during the period when they were pregnant and a control group of children of non-smoking mothers. The parameters of the psychomotor development of the children were measured using the Age & Stage Questionnaires 3® (ASQ-3).

RESULTS

Children, whose mothers were smokers themselves or who were exposed to SHS during the period of pregnancy had an average psychomotor development score of 221 points versus 243.5 points in the control group. Twenty-six percent had delays (near or under the cut-off scores) in one of the assessed psychomotor areas and 60% had two or more psychomotor delays; 36% of children whose mothers were not exposed to smoking during pregnancy had normal psychomotor development and only 34% presented multiple psychomotor delays.

CONCLUSIONS

Fetuses exposed to tobacco are more likely to achieve a psychomotor development in the 'monitor' and 'fail' areas compared to the non-exposed control group. The children exposed to smoking during their fetal development should be considered as a group at risk of developmental delays, therefore they should be closely monitored and supported by caregivers and developmental pediatricians.

Foetal mouth movements: Effects of nicotine

AIM

To assess whether foetal mouth movement frequency changes across gestation and whether there are differences between cigarette and e-cigarette exposure conditions in comparison to a non-exposed group of foetuses.

METHOD

Pregnant women underwent 4-dimensional (4D) foetal ultrasound scans at 32 weeks (106 scans) and 36 weeks of gestational age (87 scans) at James Cook University Hospital, UK. The 4D scans were coded using the Fetal Observable Movement System (FOMS). Measures of maternal smoking status, stress, depression, anxiety, attachment and time of scan were also collected. There were four exposure groups: non-smokers, light smokers (<10 per day), heavy smokers (11-20 per day) and e-cigarette users.

RESULTS

No significant differences in relative frequency of mouth movements between the exposure groups at 32- and 36 weeks of gestational age were found. Foetal mouth movements declined from 32 to 36 weeks of gestation for non-exposed and e-cigarette-exposed foetuses.

CONCLUSION

Due to variability in foetal behaviour, examining mouth movements alone may not be the most appropriate method for assessing group differences. However, in line with other research, mouth movement frequency declined between 32- and 36 weeks of gestational age. A combination of foetal behavioural assessments is needed to assess the effects of cigarette and e-cigarette exposure on foetal neurobehavioural development.

Physiological Stress Response Reactivity Mediates the Link Between Emotional Abuse and Youth Internalizing Problems

Youth who are raised in emotionally abusive families are more likely to have poor mental health outcomes such as depression and anxiety. However, the mechanisms of this association are unclear. The present study utilized a longitudinal sample of low-SES youth (N = 101, M_ageT1 = 10.24) to examine stress response reactivity (i.e. vagal withdrawal, sympathetic activation, and hypothalamic-pituitary-adrenal [HPA] axis activation) as mediators between emotional abuse and prospective youth internalizing symptoms. Results indicated that blunted HPA reactivity to a laboratory social stress task mediated the association between emotional abuse and youth internalizing symptoms. Emotional abuse was also associated with blunted parasympathetic nervous system activity (i.e. less vagal withdrawal than average). In sum, emotional abuse is a potent risk factor for youth internalizing symptoms, and this link may be mediated via dysregulation in physiological stress response systems. Primary prevention of childhood emotional abuse and secondary prevention programs that target self-regulation skills may reduce rates of youth internalizing symptoms and disorders.

Fetal neuromaturation in late gestation is affected by maternal sleep disordered breathing and sleep disruption in pregnant women with obesity

OBJECTIVE

Maternal sleep disordered breathing and sleep disruption have adverse effects on pregnancy outcomes through multiple potential pathophysiologic pathways. We hypothesize that disordered maternal sleep also adversely impacts the neuromaturation of the fetus.

METHODS

Participants in this prospective observational study included 102 obese pregnant women (pre-pregnancy body mass index [BMI] of 30 or higher) at 36 weeks of pregnancy. Fetal neuromaturation, defined through measures of fetal heart rate variability, motor activity, and motor-cardiac coupling, was quantified through digitized fetal actocardiography during an afternoon recording. Maternal sleep measures were collected overnight through polysomnography. Data analysis focused on multiple regression, controlling for maternal BMI, blood pressure, and diabetes.

RESULTS

Indicators of higher sleep disordered breathing were associated with delayed fetal neuromaturation and greater fetal motor activity. Less maternal sleep disruption (shorter rapid eye movement [REM] latency, more REM sleep, and/or fewer transitions) was associated with higher fetal heart rate variability and coupling-based neuromaturation.

CONCLUSION

Characteristics of disordered maternal sleep affect the developing fetal nervous system. It is unknown whether these results extend to populations that are not characterized by obesity. The influence of maternal sleep on the developing fetal nervous system has been understudied and may yield effects that persist beyond pregnancy.

Developmental Exposure to Air Pollution, Cigarettes, and Lead: Implications for Brain Aging

Brain development is impaired by maternal exposure to airborne toxins from ambient air pollution, cigarette smoke, and lead. Shared postnatal consequences include gray matter deficits and abnormal behaviors as well as elevated blood pressure. These unexpectedly broad convergences have implications for later life brain health because these same airborne toxins accelerate brain aging. Gene-environment interactions are shown for ApoE alleles that influence the risk of Alzheimer disease. The multigenerational trace of these toxins extends before fertilization because egg cells are formed in the grandmaternal uterus. The lineage and sex-specific effects of grandmaternal exposure to lead and cigarettes indicate epigenetic processes of relevance to future generations from our current and recent exposure to airborne toxins.

Vape flavourants dull sensory perception and cause hyperactivity in developing zebrafish embryos

E-cigarette use (vaping) during pregnancy has been increasing, and the potential exists for the developing brain in utero to be exposed to chemical constituents in the vape. Vapes come in over 7000 unique flavours with and without nicotine, and while nicotine is a known neurotoxicant, the effects of vape flavouring alone, in the absence of nicotine, on brain function are not well understood. Here, we performed a screen of vape aerosol extracts (VAEs) to determine the potential for prenatal neurotoxicity using the zebrafish embryo photomotor response (PMR)-a translational biosensor of neurobehavioural effects. We screened three commonly used aerosolized vape liquids (flavoured and flavourless) either with or without nicotine. No neurobehavioural effects were detected in flavourless, nicotine-free VAEs, while the addition of nicotine to this VAE dulled sensory perception. Flavoured nicotine-free VAEs also dulled sensory perception and caused hyperactivity in zebrafish embryos. The combination of flavour and nicotine produced largely additive effects. Flavoured VAEs without nicotine had similar neuroactive potency to nicotine. Together, using zebrafish PMR as a high throughput translational behavioural model for prenatal exposure, our results demonstrate that e-cigarette flavourants that we screened elicit neurobehavioural effects worthy of further investigation for long-term neurotoxic potential and also have the potential to modulate nicotine impact on the developing brain.

Maternal smoking in pregnancy, fetal activity & newborn behavioral state: An observational ultrasound study

Maternal smoking during pregnancy (MSDP) remains one of the most common prenatal drug exposures in the US and worldwide. MSDP is associated with medical risk for the fetus and altered behavioral development in infants; however, fewer studies have examined the impact of MSDP on fetal behavior or newborn behavioral state. We investigated associations between MSDP and (a) fetal motor activity and (b) newborn behavioral state following handling. Participants were 79 healthy mother-fetus/newborn pairs (57% MSDP-exposed). MSDP was measured by maternal interview and verified by saliva biomarkers. Mothers completed an observational fetal ultrasound assessment between 24 and 37 weeks gestation (M = 28 weeks), including baseline, vibro-acoustic stimulus and recovery periods. Total fetal motor activity and complex body movements were coded from ultrasound videos. Following delivery, newborn post-handling behavioral state was assessed by direct observational coding. MSDP exposure was associated with higher baseline fetal motor activity, particularly at younger gestational ages. Further, motor reactivity to stimulation emerged at later gestational ages in MSDP-exposed fetuses, while motor reactivity was consistent across gestational ages in unexposed fetuses. Finally, heavy MSDP exposure was associated with more arousal following handling and greater need for soothing interventions in the newborn period. Monitoring of fetal behavior via ultrasound may offer a unique opportunity to identify at-risk infants and provides data for stronger public health messaging regarding risks of MSDP. Associations between MSDP and increased newborn fussiness highlight opportunities for education and anticipatory guidance in the postpartum period.

Prenatal tobacco and marijuana co-use: Sex-specific influences on infant cortisol stress response

Although tobacco (TOB) and marijuana (MJ) are often co-used in pregnancy, little is known regarding the joint impact of MJ + TOB on offspring development, including the developing neuroendocrine stress system. Further, despite evidence for sex-specific impacts of prenatal exposures in preclinical models, the sex-specific impact of prenatal MJ + TOB exposure on offspring neuroendocrine regulation in humans is also unknown. In the current study, overall and sex-specific influences of MJ + TOB co-use on offspring cortisol regulation were investigated over the first postnatal month. 111 mother-infant pairs from a low-income, racially and ethnically diverse sample participated. Based on Timeline Followback data with biochemical verification, three groups were identified: (1) prenatal MJ + TOB, (2) TOB only, and (3) controls. Baseline cortisol and cortisol stress response were assessed at seven points over the first postnatal month using a handling paradigm in which saliva cortisol was assessed before, during, and following a standard neurobehavioral assessment (NICU Network Neurobehavioral Scale). A significant exposure group by offspring sex interaction emerged for baseline cortisol over the first postnatal month (p = .043); MJ + TOB-exposed males showed 35-36% attenuation of baseline cortisol levels vs. unexposed and TOB-exposed males (ps ≤ .003), while no effects of exposure emerged for females. Both MJ + TOB and TOB-exposed infants showed a 22% attenuation of cortisol stress response over the first postnatal month vs. unexposed infants (ps < .03), with evidence for sex-specific effects in exploratory analyses. Although results are preliminary, this is the first human study to investigate the impact of prenatal MJ exposure on infant cortisol and the first to reveal a sex-specific impact of prenatal MJ + TOB on cortisol regulation in humans. Future, larger-scale studies are needed to elucidate mechanisms and consequences of sex-specific effects of MJ and MJ + TOB on the developing neuroendocrine stress system.

Gestational exposure to nicotine and/or benzo[a]pyrene causes long-lasting neurobehavioral consequences

Tobacco smoke is a complex mixture that includes thousands of compounds. Previously, we have found that gestational exposure to the complex mixture of tobacco smoke extract caused long-term neurobehavioral impairments. In this study, we examined the interaction of two of the most biologically active, nicotine and benzo[a]pyrene (BaP). Developmental effects were determined in Sprague-Dawley rats prenatally exposed to low doses of BaP and nicotine (0.03 mg/kg/day of BaP and 2 mg/kg/day of nicotine) via maternal osmotic minipumps throughout gestation. Behavioral function was assessed in the offspring via a battery of tests through adolescence into adulthood. There were sex-selective effects in four of the behavioral tests. In the elevated plus maze, there was a significant interaction of BaP and sex, where BaP-treated males showed a trend for increased activity. In the novelty suppressed feeding test, there were significant sex selective effects in males such that the normal sex difference in the behavior in this test was eliminated. Male offspring with prenatal exposure to either nicotine or BaP showed significant reductions in fear response. In the Figure-8 locomotor activity test, BAP-exposed male offspring were significantly hyperactive. This also eliminated the sex difference typically seen in this test. This effect persisted into adulthood. In the attention task, males exposed to nicotine during gestation showed a significant percent hit impairment. BaP reversed this effect. No significant effects were seen with percent correct rejection. These data show that both nicotine and BaP cause persisting sex-selective behavioral effects that persist into adulthood.

The effect of prenatal smoke exposure on child neuropsychological function: a prospective mother-child cohort study

Objective: To study prospectively the effect of prenatal smoke exposure (PSE) on child neuropsychological function and intelligence quotient (IQ).Background: PSE has been associated with adverse effects on child neurodevelopment. However, some studies reported that these associations disappear after adjustment for potential confounders.Methods: A cohortof 248 mothers-child dyad was followed from the first trimester of pregnancy until children were 7.5 years old. PSE was recorded during pregnancy by questionnaire and plasma cotinine. The Wechsler Intelligence Scale for Children, the Neuropsychological Assessment of Executive Functions for Children (ENFEN) and the School Neuropsychological Maturity Questionnaire were administered at 7.5 years of age. The effect of PSE on child IQ and neuropsychological function was assessed with ANCOVA, adjusting for obstetric, neonatal and sociodemographic factors.Results: Children whose mothers smoked throughout pregnancy scored lower in interference (ENFEN) compared to unexposed children (F = 4.1; p = .008). The results showed no differences in other executive functions, verbal and visual memory and IQ between the PSE groups.Conclusion: PSE had little effect on child neuropsychological outcome and was limited to mental flexibility. Nevertheless, these findings support further efforts aimed at encouraging mothers to quit smoking in pregnancy.

Prenatal tobacco and marijuana co-use: Impact on newborn neurobehavior

Tobacco and marijuana are some of the most common prenatal substance exposures worldwide. The social acceptability and political landscape of marijuana and its potency have changed dramatically in the last two decades leading to increased use by pregnant women. Despite evidence for increasing marijuana use and high rates of co-use of tobacco (TOB) and marijuana (MJ) during pregnancy, the impact of prenatal exposure to each substance is typically studied in isolation. We investigated the influence of co-exposure to TOB and MJ on infant neurobehavioral development over the first postnatal month. Participants were 111 mother-infant pairs from a low-income, diverse sample (Mean age = 25 ± 5; 54% minorities). TOB and MJ use were assessed by Timeline Followback interview with biochemical confirmation. Three groups were identified: (a) prenatal MJ + TOB, (b) prenatal TOB only, (c) controls. Newborn neurobehavior was assessed at seven time points over the first postnatal month using the NICU Network Neurobehavioral Scale. MJ + TOB-exposed infants showed decreased ability to self-soothe (Self-regulation) and attend to stimuli (Attention), and increased need for examiner soothing (Handling) and low motor activity (Lethargy) versus unexposed infants. Despite low levels of MJ use in MJ + TOB co-users, co-exposure was associated with nearly double the impact on infant self-soothing and need for examiner soothing versus TOB-exposure alone. Effects of MJ + TOB co-exposure appeared more pronounced for daughters than for sons. Although results are preliminary, they highlight additional risk from dual exposure to MJ + TOB vs. TOB exposure alone, particularly for daughters. Results also highlight the critical importance of investigating prenatal exposures in concert and the need for intervention efforts to address MJ co-use in pregnant TOB users.