High-risk pregnancies elevate maternal stress, impacting offspring neurodevelopment and behavior. This study, involving 112 participants, aimed to compare perceived stress, neurodevelopment, and behavior in high-risk and low-risk pregnancies. Two groups, high-risk and low-risk, were assessed during pregnancy for stress using hair cortisol and psychological analysis. At 24 months post-birth, their children’s neurodevelopment and behavior were evaluated. Results revealed higher perceived stress and pregnancy-related concerns in high-risk pregnancies, contrasting with low-risk pregnancies. Offspring from high-risk pregnancies displayed elevated internalizing behavior scores, while low-risk pregnancies showed higher externalizing behavior scores. Additionally, women in low-risk pregnancies exhibited increased cortisol concentrations 24 months post-delivery. These findings underscore the necessity for early stress detection and prevention programs during pregnancy, particularly in high-risk cases, to enhance maternal and infant health.

Prenatal maternal stress and mental health problems are known to increase risk for developmental psychopathology in offspring, yet pathways leading to risk or resiliency are poorly understood. In a quasi-experimental design, we prospectively examined associations between disaster-related prenatal stress, maternal mental health symptoms, and infant temperament outcomes. Mothers who were pregnant during Hurricane Harvey (N = 527) reported on objective hardships (e.g., loss of belongings or income, evacuation, home flooding) related to the storm and subsequent mental health symptoms (anxiety/depression, posttraumatic stress) across time. At a postpartum assessment, mothers reported on their infant’s temperament (negative affect, positive affect, orienting/regulatory capacity). Greater objective hardship indirectly predicted higher levels of infant orienting/regulatory capacity through its association with increased maternal posttraumatic stress symptoms. Greater objective hardship also indirectly predicted higher levels of infant negative affect through its association with increased maternal anxiety/depression symptoms across time. Our findings suggest a psychological mechanism linking prenatal stress with specific temperamental characteristics via maternal mental health symptoms. Findings point to the importance of high-quality assessment and mental health services for vulnerable women and young children.

Attention biases to threat are considered part of the etiology of anxiety disorders. Attention bias variability (ABV) quantifies intraindividual fluctuations in attention biases and may better capture the relation between attention biases and psychopathology risk versus mean levels of attention bias. ABV to threat has been associated with attentional control and emotion regulation, which may impact how caregivers interact with their child. In a relatively diverse sample of infants (50% White, 50.7% female), we asked how caregiver ABV to threat related to trajectories of infant negative affect across the first 2 years of life. Families were part of a multi-site longitudinal study, and data were collected from 4 to 24 months of age. Multilevel modeling examined the effect of average caregiver attention biases on changes in negative affect. We found a significant interaction between infant age and caregiver ABV to threat. Probing this interaction revealed that infants of caregivers with high ABV showed decreases in negative affect over time, while infants of caregivers with low-to-average ABV showed potentiated increases in negative affect. We discuss how both high and extreme patterns of ABV may relate to deviations in developmental trajectories.

Perturbations to the gut microbiome are implicated in altered neurodevelopmental trajectories that may shape life span risk for emotion dysregulation and affective disorders. However, the sensitive periods during which the microbiome may influence neurodevelopment remain understudied. We investigated relationships between gut microbiome composition across infancy and temperament at 12 months of age. In 67 infants, we examined if gut microbiome composition assessed at 1–3 weeks, 2, 6, and 12 months of age was associated with temperament at age 12 months. Stool samples were sequenced using the 16S Illumina MiSeq platform. Temperament was assessed using the Infant Behavior Questionnaire-Revised (IBQ-R). Beta diversity at age 1–3 weeks was associated with surgency/extraversion at age 12 months. Bifidobacterium and Lachnospiraceae abundance at 1–3 weeks of age was positively associated with surgency/extraversion at age 12 months. Klebsiella abundance at 1–3 weeks was negatively associated with surgency/extraversion at 12 months. Concurrent composition was associated with negative affectivity at 12 months, including a positive association with Ruminococcus-1 and a negative association with Lactobacillus. Our findings support a relationship between gut microbiome composition and infant temperament. While exploratory due to the small sample size, these results point to early and late infancy as sensitive periods during which the gut microbiome may exert effects on neurodevelopment.

Children with cows' milk protein allergy (CMPA) are at risk of insufficient length and weight gain, and the nutritional efficacy of hypo-allergenic formulas should be carefully assessed. In 2008, a trial assessed the impact of probiotic supplementation of an extensively hydrolysed casein-based formula (eHCF) on acquisition of tolerance in 119 infants with CMPA. First analysis of the study results showed that the studied formula allowed improvement of food-related symptoms. The scoring of atopic dermatitis (SCORAD) index was assessed at randomisation and after 6 months of feeding. A post hoc analysis was performed using WHO growth software's nutritional survey module (WHO Anthro version 3.2.2). All infants who were fed the study formula tolerated it well. The SCORAD index significantly improved from randomisation to 6 months of feeding with the study formula. Anthropometric data indicated a significant improvement in the weight-for-age, length-for-age and weight-for-length z scores, as well as in the restoration of normal BMI. The probiotic supplementation did not show any impact on these parameters. The present data showed that this eHCF was clinically tolerated and significantly improved the SCORAD index and growth indices.

Bilingual advantages in memory flexibility, indexed using a memory generalization task, have been reported (Brito & Barr, 2012; 2014), and the present study examines what factors may influence memory performance. The first experiment examines the role of language similarity; bilingual 18-month-old infants exposed to two similar languages (Spanish–Catalan) or two more different (English–Spanish) languages were tested on a memory generalization task and compared to monolingual 18-month-olds. The second experiment compares performance by trilingual 18-month-olds to monolingual and bilingual infants’ performance from the first experiment. The bilingual advantage in memory flexibility was robust; both bilingual groups outperformed the monolingual groups, with no significant differences between bilingual groups. Interestingly, an advantage was not found for infants exposed to three languages. These findings demonstrate early emerging differences in memory flexibility, and have important implications for our understanding of how early environmental variations shape the trajectory of memory development.

According to the literature about developmental changes, periods of instability and disorganization in the social and emotional behavior in both human and non-human primate, infancy precedes major developmental achievements or transitions (Heimann, 2003; Sparrow & Brazelton, 2006). Developmental investigators have observed a more frequent and prolonged crying, clinging and bids for physical contact with mother during these periods of instability and disorganization. Some authors, according to Horwich (1974), called these periods regression periods. Rijt-Plooij and Plooij (1992) claimed that 10 regression periods could be identified during the first 20 months of human life. In an early study, Sadurní and Rostan (2002) confirmed the presence of 8 such regression periods during the first year of life of 18 Catalan babies. Their 8 regression periods were comparable to the first 8 of the 10 regression periods found by Van de Rijt Plooij and Plooij. The aim of the present study is to see whether the regression periods that we found are temporally related to some transition. We define a transition as the occurrence of a new developmental change in a child. In the present study we have used non-analyzed data from the same 18 Catalan babies (10 boys and 8 girls) as mentioned in our earlier published study on regression periods. The age of these babies was between 3 weeks and 14 months. Using a microgenetic methodology we have found 8 transitions periods in the first year of life. We have also observed a temporal relation between the regressions periods found earlier and the transition periods reported here.

Children growing up bilingual face a unique linguistic environment. The current study investigated whether early bilingual experience influences the developmental trajectory of associative word learning, a foundational mechanism for lexical acquisition. Monolingual and bilingual infants (N = 98) were tested on their ability to learn dissimilar-sounding words (lif and neem) in the Switch task. Twelve-month-olds from both language backgrounds failed to detect a violation of a previously taught word–object pairing. However, both monolinguals and bilinguals succeeded at 14 months, and their performance did not differ. The results indicate that early bilingual experience does not interfere with the development of the fundamental ability to form word–object associations, suggesting that this mechanism is robust across different early language environments.

Is parental language mixing related to vocabulary acquisition in bilingual infants and children? Bilingual parents (who spoke English and another language; n = 181) completed the Language Mixing Scale questionnaire, a new self-report measure that assesses how frequently parents use words from two different languages in the same sentence, such as borrowing words from another language or code switching between two languages in the same sentence. Concurrently, English vocabulary size was measured in the bilingual children of these parents. Most parents reported regular language mixing in interactions with their child. Increased rates of parental language mixing were associated with significantly smaller comprehension vocabularies in 1.5-year-old bilingual infants, and marginally smaller production vocabularies in 2-year-old bilingual children. Exposure to language mixing might obscure cues that facilitate young bilingual children's separation of their languages and could hinder the functioning of learning mechanisms that support the early growth of their vocabularies.

Human milk provides all the dietary essential fatty acids, linoleic acid (LA; 18:2n-6) and α-linolenic acid (18:3n-3), as well as their longer-chain more-unsaturated metabolites, including arachidonic acid (20:4n-6) and DHA (22:6n-3) to support the growth and development of the breast-fed infant. Human milk levels of LA have increased in Westernized nations from mean levels (g/100 g total fatty acids) of 6 to 12–16 over the last century, paralleling the increase in dietary intake of LA-rich vegetable oils. DHA levels (g/100 g total milk fatty acids) vary from <0·1 to >1% and are lowest in countries in which the intake of DHA from fish and other animal tissue lipids is low. The role of DHA in infant nutrition is of particular importance because DHA is accumulated specifically in the membrane lipids of the brain and retina, where it is important to visual and neural function. An important question is the extent to which many human diets that contain low amounts of n-3 fatty acids may compromise human development. The present paper reviews current knowledge on maternal diet and human milk fatty acids, the implications of maternal diet as the only source of essential fatty acids for infant development both before and after birth, and recent studies addressing the maternal intakes and milk DHA levels associated with risk of low infant neural system maturation.

The overall goal of this target article is to demonstrate a mechanism for an embodied cognition. The particular vehicle is a much-studied, but still widely debated phenomenon seen in 7–12 month-old-infants. In Piaget's classic “A-not-B error,” infants who have successfully uncovered a toy at location “A” continue to reach to that location even after they watch the toy hidden in a nearby location “B.” Here, we question the traditional explanations of the error as an indicator of infants' concepts of objects or other static mental structures. Instead, we demonstrate that the A-not-B error and its previously puzzling contextual variations can be understood by the coupled dynamics of the ordinary processes of goal-directed actions: looking, planning, reaching, and remembering. We offer a formal dynamic theory and model based on cognitive embodiment that both simulates the known A-not-B effects and offers novel predictions that match new experimental results. The demonstration supports an embodied view by casting the mental events involved in perception, planning, deciding, and remembering in the same analogic dynamic language as that used to describe bodily movement, so that they may be continuously meshed. We maintain that this mesh is a pre-eminently cognitive act of “knowing” not only in infancy but also in everyday activities throughout the life span.

Studies of developmental progress in high-risk twins have disparate findings. In this study, we report the outcome of 45 twin pairs born between 26 and 37 weeks gestation, and whose birthweights ranged from 840 to 2000 g. No significant differences were found for weight, risk and birth order. However, earlier preterm infants were found to have significantly lower mental scores on the Bayley Scales of Infant Development at 24 months, and lower IQ scores on the Stanford Binet Intelligence Scale at 36 months. These findings imply that gestational age is a powerful variable in determining developmental outcome.