Effects of Prenatal Nicotine Exposure on Infant Language Development: A Cohort Follow Up Study

What risk factors for Developmental Language Disorder can tell us about the neurobiological mechanisms of language development

Language is a complex multidimensional cognitive system that is connected to many neurocognitive capacities. The development of language is therefore strongly intertwined with the development of these capacities and their neurobiological substrates. Consequently, language problems, for example those of children with Developmental Language Disorder (DLD), are explained by a variety of etiological pathways and each of these pathways will be associated with specific risk factors. In this review, we attempt to link previously described factors that may interfere with language development to putative underlying neurobiological mechanisms of language development, hoping to uncover openings for future therapeutical approaches or interventions that can help children to optimally develop their language skills.

Maternal nicotine intoxication before pregnancy induces depressive- and anxiety-like behaviors as well as cognitive deficits in male offspring and correlates with neurobiological changes

INTRODUCTION

Maternal nicotine use has been suggested to affect the behavior of children and is linked to changes in neurological systems; however, the specific mechanism is yet to be understood.

METHODS

Mice were used to establish a maternal nicotine intoxication model. At postnatal day 60 (adolescent stage), male offspring were tested for behavioral tasks including sucrose preference, open field, elevated plus maze, light/dark box, object recognition, Morris water maze (MWM), and forced swimming. Enzyme-linked immunoassays were used to measure plasma concentrations of neurotransmitters including norepinephrine, dopamine, serotonin, and corticosterone. Serotonin transporter (Sert), brain-derived neurotrophic factor (Bdnf), cAMP response element binding protein (Creb), and phosphorylated (p)Creb mRNA levels were measured using quantitative real-time polymerase chain reaction.

RESULTS

Male offspring of nicotine-intoxicated dams had significantly reduced sucrose preference, mobility time in the forced swimming test, and locomotor and exploratory activities. Offspring in the maternal nicotine intoxication group showed increased signs of depressive- and anxiety-like behavior. Recognition memory in the MWM was compromised in these animals. The hippocampal and prefrontal cortical regions showed significant changes in Bdnf, pCreb, and Sert gene expression, whereas CREB mRNA levels were unaffected. Moreover, compared to the controls, neurogenesis and neuronal viability were also reduced in these animals.

CONCLUSION

Prenatal nicotine exposure might affect the hypothalamic-pituitary-adrenal axis and reduce neurogenesis, potentially leading to depressive-like behaviors and cognitive deficiencies in male offspring.

Maternal Vitamin B12 Status during Pregnancy and Early Infant Neurodevelopment: The ECLIPSES Study

In this prospective cohort study of 434 mother-infant pairs from the ECLIPSES study, we examine the association between maternal vitamin B12 status at the beginning and end of pregnancy and the neurodevelopmental outcomes of infants 40 days after birth in a pregnant population from a Mediterranean region of northern Spain. Maternal vitamin B12 concentrations were determined in the first and third trimesters, and sociodemographic, nutritional, and psychological data were collected. At 40 days postpartum, the Bayley Scales of Infant Development-III (BSID-III, cognitive, language, and motor skills) were administered to the infants and several obstetrical data were recorded. In the multivariable models, medium maternal first-trimester vitamin B12 levels (312 to 408 pg/mL, tertile 2) were associated with better neonatal performance in the motor, gross motor, language, and cognitive skills with respect to tertile 1 (<312 pg/mL). The probability of obtaining a neonatal motor, gross motor, and receptive language score >75th percentile was significantly higher also in the tertile 2 group. In summary, good maternal vitamin B12 status in the early stage of pregnancy appears to be associated with better infant motor, language, and cognitive performance at 40 days postpartum.

Association between neonatal near miss and infant development: the Ribeirão Preto and São Luís birth cohorts (BRISA)

AIM

To analyze the association between neonatal near miss and infant development at two years.

METHODS

Data from two birth cohorts, one conducted in Ribeirão Preto (RP)/São Paulo and the other in São Luís (SL)/Maranhão, were used. The cognitive, motor and communication development of children was evaluated using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). The following criteria were used for the definition of NNM: birth weight < 1,500 g, 5-min Apgar score < 7, gestational age < 32 weeks, and report of congenital malformations. The relationship between neonatal near miss and development was assessed using the weighted propensity score from the Inverse Probability of Treatment Weighting (IPTW). A directed acyclic graph was built to select the adjustment variables.

RESULTS

A total of 1,050 mother-newborn dyads were evaluated in SL and 1,840 in RP. Regarding outcomes in SL and RP, respectively, 2.4% and 17.3% of the children were not competent in the cognitive domain, 12.1% and 13.3% in the receptive communication domain, 39.2% and 47.1% in the expressive communication domain, 20.7% and 12.6% in the fine motor domain, and 14.3% and 13.8% in the gross motor domain. The prevalence of neonatal near miss was 5.4% in SL and 4.3% in RP. Unadjusted analysis showed an association of neonatal near miss with fine motor development in SL and RP and with the cognitive, receptive communication, expressive communication, and gross motor domains only in RP. These associations remained after adjusted analysis.

CONCLUSION

Neonatal near miss is a risk factor for developmental delays.

Average treatment effect of maternal prenatal tobacco smoking on offspring developmental vulnerability in early childhood

BACKGROUND

Early childhood developmental vulnerability has been closely related to the predictors of relatively good health, social and educational outcomes later in adulthood. However, the impacts of prenatal tobacco exposure on childhood developmental vulnerability have been rarely examined. Further, a few of the studies that have investigated maternal prenatal tobacco smoking and child developmental vulnerability have reported mixed results and there are currently no published estimates derived from causal epidemiological methods.

METHODS

We conducted a retrospective population-based cohort study on the association between maternal prenatal tobacco smoking and developmental vulnerability in children born in Western Australia (WA). De-identified individual-level maternal, infant and birth records were obtained from the Midwives Notification System (MNS), a statutory record of all births in WA. WA register for Developmental Anomalies (WARDA) were also obtained from the WA Data Linkage. Records on early childhood developmental vulnerability at the median age of 5 years were obtained from the Australian Early Development Census (AEDC). We used a doubly robust estimator to estimate the causal effects.

RESULTS

Complete data were available for 64,558 mothers-children's pairs. Approximately 16% of children were exposed to maternal prenatal tobacco smoking. Children exposed to maternal prenatal tobacco smoking were more likely to be classified as developmentally vulnerable/at-risk on the physical health and wellbeing (RR = 1.40, 95%CI:1.36-1.45), social competence (RR = 1.42, 95%CI: 1.38-1.47), emotional maturity (RR = 1.34, 95%CI:1.30-1.39), language and cognitive skills (RR = 1.50, 95%CI:1.45-1.54), and communication skills and general knowledge (RR = 1.37, 95%CI:1.33-1.42) domains.

CONCLUSION

Maternal prenatal exposure to tobacco may influence early childhood developmental vulnerability. Early intervention to quit tobacco smoking before becoming pregnant could potentially reduce later childhood developmental vulnerability on multiple domains.

Maternal-fetal attachment and social-emotional development in infants at 3 months of age: A population-based study in southern Brazil