Behavioral gender differences in the neonatal period according to the Brazelton scale

Effects of Mediterranean diet or mindfulness-based stress reduction on fetal and neonatal brain development: a secondary analysis of a randomized clinical trial

BACKGROUND

Maternal suboptimal nutrition and high stress levels are associated with adverse fetal and infant neurodevelopment.

OBJECTIVE

This study aimed to investigate if structured lifestyle interventions involving a Mediterranean diet or mindfulness-based stress reduction during pregnancy are associated with differences in fetal and neonatal brain development.

STUDY DESIGN

This was a secondary analysis of the randomized clinical trial Improving Mothers for a Better Prenatal Care Trial Barcelona that was conducted in Barcelona, Spain, from 2017 to 2020. Participants with singleton pregnancies were randomly allocated into 3 groups, namely Mediterranean diet intervention, stress reduction program, or usual care. Participants in the Mediterranean diet group received monthly individual sessions and free provision of extra-virgin olive oil and walnuts. Pregnant women in the stress reduction group underwent an 8-week mindfulness-based stress reduction program adapted for pregnancy. Magnetic resonance imaging of 90 fetal brains was performed at 36 to 39 weeks of gestation and the Neonatal Neurobehavioral Assessment Scale was completed for 692 newborns at 1 to 3 months. Fetal outcomes were the total brain volume and lobular or regional volumes obtained from a 3-dimensional reconstruction and semiautomatic segmentation of magnetic resonance images. Neonatal outcomes were the 6 clusters scores of the Neonatal Neurobehavioral Assessment Scale. Multiple regression analyses were conducted to assess the association between the interventions and the fetal and neonatal outcomes.

RESULTS

When compared with the usual care group, the offspring exposed to a maternal Mediterranean diet had a larger total fetal brain volume (mean, 284.11 cm3; standard deviation, 23.92 cm3 vs 294.01 cm3; standard deviation, 26.29 cm3; P=.04), corpus callosum (mean, 1.16 cm3; standard deviation, 0.19 cm3 vs 1.26 cm3; standard deviation, 0.22 cm3; P=.03), and right frontal lobe (44.20; standard deviation, 4.09 cm3 vs 46.60; standard deviation, 4.69 cm3; P=.02) volumes based on magnetic resonance imaging measures and higher scores in the Neonatal Neurobehavioral Assessment Scale clusters of autonomic stability (mean, 7.4; standard deviation, 0.9 vs 7.6; standard deviation, 0.7; P=.04), social interaction (mean, 7.5; standard deviation, 1.5 vs 7.8; standard deviation, 1.3; P=.03), and range of state (mean, 4.3; standard deviation, 1.3 vs 4.5; standard deviation, 1.0; P=.04). When compared with the usual care group, offspring from the stress reduction group had larger fetal left anterior cingulate gyri volume (1.63; standard deviation, 0.32 m3 vs 1.79; standard deviation, 0.30 cm3; P=.03) based on magnetic resonance imaging and higher scores in the Neonatal Neurobehavioral Assessment Scale for regulation of state (mean, 6.0; standard deviation, 1.8 vs 6.5; standard deviation, 1.5; P<.01).

CONCLUSION

Maternal structured lifestyle interventions involving the promotion of a Mediterranean diet or stress reduction during pregnancy were associated with changes in fetal and neonatal brain development.

Sex differences in neural processing of speech in neonates

The large majority of studies shows that girls develop their language skills faster than boys in the first few years of life. Are girls born with this advantage in language development? The present study used fNIRS in neonates to investigate sex differences in neural processing of speech within the first days of life. We found that speech stimuli elicited significantly more brain activity than non-speech stimuli in both groups of male and female neonates. However, whereas girls showed significant HbO changes to speech stimuli only within the left hemisphere, boys exhibited simultaneous neural activations in both hemispheres, with a larger and more significant fronto-temporal cluster in the right hemisphere. Furthermore, in boys, the variation in time-to-peak latencies was considerably greater than in girls. These findings suggest an earlier maturation of language-related brain areas in girls and highlight the importance of sex-specific investigations of neural language networks in infants.

Auditory Processing of the Brain Is Enhanced by Parental Singing for Preterm Infants

As the human auditory system is highly malleable in infancy, perinatal risk factors, such as preterm birth, may affect auditory development. In comparison to healthy full-term infants, preterm infants show abnormal auditory brain responses at term age, which may have long-term detrimental outcomes. To achieve an optimal neonatal care environment for preterm-born infants, many early interventions have been developed. Musical interventions developed for neonatal intensive care units (NICUs) have shown beneficial effects on vital functions and weight gain of preterm infants and might also influence basic auditory processing and thereby enhance outcomes. In the present study, we tested the effect of parental singing during kangaroo care on auditory processing of standardized audio stimuli. Preterm infants (born between 24 and 32 weeks of gestation) were randomized to singing intervention (n = 13) or control (n = 8) groups. The auditory processing was tested using two audio paradigms assessed with magnetoencephalography (MEG) at term corresponding age. To verify that the paradigms elicit responses in MEG, we studied 12 healthy full-term infants. In the singing intervention group, parents were instructed by a music therapist twice a week for 4 weeks to sing or hum during kangaroo care in an infant-directed way. The control group received standard kangaroo care. The results show that the infants in the singing intervention group show larger neural responses than those in the control group when controlling for the total amount of singing during kangaroo care. Our findings suggest that incorporating singing into kangaroo care may be beneficial for preterm infants, but the effect may not be due to exposure to singing but instead positive parenting, improved parental self-esteem and improved caregiver sensitivity.

Using Vector Autoregression Modeling to Reveal Bidirectional Relationships in Gender/Sex-Related Interactions in Mother-Infant Dyads

Vector autoregression (VAR) modeling allows probing bidirectional relationships in gender/sex development and may support hypothesis testing following multi-modal data collection. We show VAR in three lights: supporting a hypothesis, rejecting a hypothesis, and opening up new questions. To illustrate these capacities of VAR, we reanalyzed longitudinal data that recorded dyadic mother-infant interactions for 15 boys and 15 girls aged 3 to 11 months of age. We examined monthly counts of 15 infant behaviors and 13 maternal behaviors (Seifer et al., 1994). VAR models demonstrated that infant crawling predicted a subsequently close feedback loop from mothers of boys but a subsequently open-ended, branched response from mothers of girls. A different finding showed that boys' standing independently predicted significant later increases of four maternal behaviors: rocking/jiggling, lifting, affectionate touching, and stimulation of infant gross-motor activity. In contrast, crawling by girls led mothers to later decrease the same maternal behaviors. Thus, VAR might allow us to identify how mothers respond differently during daily interactions depending on infant gender/sex. The present work intends to mainly showcase the VAR method in the specific context of the empirical study of gender/sex development.

Global and Regional Changes in Cortical Development Assessed by MRI in Fetuses with Isolated Nonsevere Ventriculomegaly Correlate with Neonatal Neurobehavior

BACKGROUND AND PURPOSE

Fetuses with isolated nonsevere ventriculomegaly (INSVM) are at risk of presenting neurodevelopmental delay. However, the currently used clinical parameters are insufficient to select cases with high risk and determine whether subtle changes in brain development are present and might be a risk factor. The aim of this study was to perform a comprehensive evaluation of cortical development in INSVM by magnetic resonance (MR) imaging and assess its association with neonatal neurobehavior.

MATERIALS AND METHODS

Thirty-two INSVM fetuses and 29 healthy controls between 26-28 weeks of gestation were evaluated using MR imaging. We compared sulci and fissure depth, cortical maturation grading of specific areas and sulci and volumes of different brain regions obtained from 3D brain reconstruction of cases and controls. Neonatal outcome was assessed by using the Neonatal Behavioral Assessment Scale at a mean of 4 ± 2 weeks after birth.

RESULTS

Fetuses with INSVM showed less profound and underdeveloped sulcation, including the Sylvian fissure (mean depth: controls 16.8 ± 1.9 mm, versus INSVM 16.0 ± 1.6 mm; P = .01), and reduced global cortical grading (mean score: controls 42.9 ± 10.2 mm, versus INSVM: 37.8 ± 9.9 mm; P = .01). Fetuses with isolated nonsevere ventriculomegaly showed a mean global increase of gray matter volume (controls, 276.8 ± 46.0 ×10 mm³, versus INSVM 277.5 ± 49.3 ×10 mm³, P = .01), but decreased mean cortical volume in the frontal lobe (left: controls, 53.2 ± 8.8 ×10 mm³, versus INSVM 52.4 ± 5.4 ×10 mm³; P = < .01). Sulcal depth and brain volumes were significantly associated with the Neonatal Behavioral Assessment Scale severity (P = .005, Nagelkerke R² = 0.732).

CONCLUSIONS

INSVM fetuses showed differences in cortical development, including regions far from the lateral ventricles, that are associated with neonatal neurobehavior. These results suggest the possible use of these parameters to identify cases at higher risk of altered neurodevelopment.

Neonatal Behavioral Assessment Scale (NBAS): Confirmatory factor analysis of the six behavioral clusters

The Neonatal Behavioral Assessment Scale (NBAS) is a widely used in the neurobehavioral assessment of neonates in clinical practice and research. Lester's data reduction system for the NBAS items is the most often used in research, but the few factor analytic studies carried out with it leave gaps in its validation. The current study aimed to test and compare (a) the factorial structure of the Lester's data reduction system for the NBAS and (b) an alternative data reduction system, slightly modified from Lester's system. The NBAS was administered to 196 healthy Portuguese full-term infants (51% male) in the first 72 h of life (M = 43.63 h). Construct validity of the data reduction systems was tested through confirmatory factor analysis (CFA). Lester's original system was compared to three alternative models, two of which included a revision of the scoring rules for three items and the exclusion of five items. The CFA generally supported the six-factor structure. However, fit indices for Lester's original model were only fair. An alternative, revised model with a second-order factor - Self-Organizing System - demonstrated a better fit. The results provide evidence to support a modified form of Lester's six behavioral clusters as a data reduction model for the NBAS items.

Impact of Demographic and Obstetric Factors on Infant Brain Volumes: A Population Neuroscience Study

Individual differences in neuroanatomy are associated with intellectual ability and psychiatric risk. Factors responsible for this variability remain poorly understood. We tested whether 17 major demographic and obstetric variables were associated with individual differences in brain volumes in 756 neonates assessed with MRI. Gestational age at MRI, sex, gestational age at birth, and birthweight were the most significant predictors, explaining 31% to 59% of variance. Unexpectedly, earlier born babies had larger brains than later born babies after adjusting for other predictors. Our results suggest earlier born children experience accelerated brain growth, either as a consequence of the richer sensory environment they experience outside the womb or in response to other factors associated with delivery. In the full sample, maternal and paternal education, maternal ethnicity, maternal smoking, and maternal psychiatric history showed marginal associations with brain volumes, whereas maternal age, paternal age, paternal ethnicity, paternal psychiatric history, and income did not. Effects of parental education and maternal ethnicity are partially mediated by differences in birthweight. Remaining effects may reflect differences in genetic variation or cultural capital. In particular late initiation of prenatal care could negatively impact brain development. Findings could inform public health policy aimed at optimizing child development.

Prenatal Depressive Symptoms and Toddler Behavior Problems: The Role of Maternal Sensitivity and Child Sex

Increasing evidence suggests that maternal depression during pregnancy is associated with child behavioral outcomes even after accounting for later maternal depression. The purpose of this study was to examine various mechanisms, including maternal sensitivity, neonatal problems, and concurrent maternal depression, that might explain the association between prenatal maternal depressive symptoms and toddler behavior problems. Young, low income, African American mothers (n = 196) were interviewed during pregnancy and at 24-months postpartum, medical records were collected at the birth, and mother-child interactions were video-recorded at 24 months. Path analyses revealed that the association between prenatal depression and toddler behavior problems was mediated by maternal sensitivity and maternal depressive symptoms at 24 months. No evidence was found for a mediating effect of neonatal problems. Path models examining sex differences suggested that different mediating factors may be important for boys and girls, with boys being particularly susceptible to the effects of maternal sensitivity.

How else can we study sex differences in early infancy?

This paper revisits group difference and individual variability in birth weight, head size, Apgar score, and motor performance in neonatal and 8-month-old males and females using a large existing data set. The goal is primarily theoretical--to reframe existing analyses with an eye toward designing and executing more predictive analyses in the future. 3D graphing to visualize both the areas of overlap and regions of disparity between boys and girls has been used. A two-step cluster analysis of boys and girls together revealed three clusters. One was almost equally divided between boys and girls, but a second was highly enriched for boys and the third highly skewed toward girls. The relationship between cluster membership and Bayley motor scores at 8 months tested the hypothesis that initial differences that have no sex-related behavioral content might start processes that produce later sex-related differences. Initially, parental belief systems may be less important than infant care patterns evoked by basic size and health characteristics, even though later parental behaviors assume a decidedly gendered pattern.

The effects of olfactory stimulation and gender differences on pain responses in full-term infants

AIM

Studies have reported conflicting findings on whether different smells can reduce distress when infants undergo painful procedures. Our study assessed the impact of vanilla on infants' responses to a painful toe lance, including possible gender differences.

METHODS

We measured the pain responses of 69 full-term infants - 34 girls and 35 boys - during toe lance, using two multidimensional scales - the Neonatal Facial Coding System and Behavioural Indicators of Infant Pain - together with crying duration and hand movements. Three sets of data were collected during baseline, toe lance and recovery, while the babies were exposed to the odour of vanilla (n = 39) or odourless water (n = 30).

RESULTS

Pain responses increased significantly during toe lance, then declined during recovery. Crying duration correlated significantly with finger splaying/fisting and both pain scale scores, with boys displaying higher pain scores than girls. Vanilla had no impact on pain levels.

CONCLUSION

Crying and finger splaying/fisting were observable responses that may be useful for screening pain or distress in healthy neonates. Increased pain reactions by boys may reflect higher irritability. Exposure to an unfamiliar odour did not have a calming effect on full-term neonates.

Neurobehavioral development of preterm and full term children: biomedical and environmental influences

BACKGROUND

Previous studies indicate that VLBW preterm children obtain significantly lower scores than full-term children in all the NBAS clusters. However the samples studied usually presented additional medical complications.

AIMS

The present study aims to compare the results obtained by low-risk preterm and full term children in the NBAS, and relate possible differences to biological and contextual factors.

METHOD

Early neurobehavioral development of 150 preterm (PR) children is compared to that of 49 full term children (FT). The children were assessed at the age of 15 days (corrected age for preterm children) with the NBAS. Biological and environmental variables were collected through an extended interview with the mothers as well as medical data.

RESULTS

Significant differences were found between preterm and full term children in the following areas: motor, range of state, and regulation of state. Differences were also found in relation to birth weight in these same three areas, following a parallel pattern. These differences between the two groups were not, however, necessarily more favorable for the FT group; the PR group had higher results in the motor and range of state areas, and lower results in the regulation of state area. The mothers' smoking habit had a negative effect on infants' regulation and orientation.

CONCLUSIONS

No general maturation delay in this particular sample of preterm children was found.

Impact of sex and gonadal steroids on neonatal brain structure

There are numerous reports of sexual dimorphism in brain structure in children and adults, but data on sex differences in infancy are extremely limited. Our primary goal was to identify sex differences in neonatal brain structure. Our secondary goal was to explore whether brain structure was related to androgen exposure or sensitivity. Two hundred and ninety-three neonates (149 males) received high-resolution structural magnetic resonance imaging scans. Sensitivity to androgen was measured using the number of cytosine, adenine, guanine (CAG) triplets in the androgen receptor gene and the ratio of the second to fourth digit, provided a proxy measure of prenatal androgen exposure. There was a significant sex difference in intracranial volume of 5.87%, which was not related to CAG triplets or digit ratios. Tensor-based morphometry identified extensive areas of local sexual dimorphism. Males had larger volumes in medial temporal cortex and rolandic operculum, and females had larger volumes in dorsolateral prefrontal, motor, and visual cortices. Androgen exposure and sensitivity had minor sex-specific effects on local gray matter volume, but did not appear to be the primary determinant of sexual dimorphism at this age. Comparing our study with the existing literature suggests that sex differences in cortical structure vary in a complex and highly dynamic way across the human lifespan.

What lies behind postnatal depression: is it only a mood disorder?

Postnatal depression (PND) is a common condition that has been extensively researched specifically because of its negative impact on the mother-infant relationship. Psychiatric research has looked at comorbidity of major depressive disorder and found it to be strongly associated with Axis II disorders. This study's principal aim was to investigate whether there is a greater incidence of personality disorder (PD) among a PND population than among a non-PND population at 3 months postpartum. A secondary aim was to define the different types of PD. Depression was assessed with the Montgomery and Asberg Depression Rating Scale (MADRS), and PD was assessed with the Structured Interview for DSM-IV Personality Disorders (SIDP-IV) in 109 women with their 12-week-old infants. Twice as many depressed mothers had PD. The PND group presented a greater number of severe clinical symptoms than the nondepressed group (p < .002). Further research is necessary to reexamine the heterogeneity of PND and reassess its impact on infant development.

Neurobehavioral outcomes in preterm, growth-restricted infants with and without prenatal advanced signs of brain-sparing

OBJECTIVE

To evaluate the neurobehavioral outcomes of preterm infants with intrauterine growth restriction (IUGR), with and without prenatal advanced brain-sparing.

METHODS

A cohort of IUGR infants (birth weight < 10(th) percentile with abnormal umbilical artery Doppler) born before 34 weeks of gestation was compared with a control group of appropriate-for-gestational age infants matched for gestational age at delivery. MCA pulsatility index was determined in all cases within 72 hours before delivery. Neonatal neurobehavior was evaluated at 40 weeks' ( ± 1) corrected age using the Neonatal Behavioral Assessment Scale. The effect of abnormal MCA pulsatility index (< 5(th) percentile) on each neurobehavioral area was adjusted for maternal smoking status and socioeconomic level, mode of delivery, gestational age at delivery, pre-eclampsia, newborn illness severity score and infant sex by multiple linear and logistic regression.

RESULTS

A total of 126 preterm newborns (64 controls and 62 IUGR) were included. Among IUGR fetuses, the proportion of abnormal MCA Doppler parameters was 53%. Compared with appropriate-for-gestational age infants, newborns in the IUGR subgroup with abnormal MCA Doppler had significantly lower neurobehavioral scores in the areas of habituation, motor system, social-interactive and attention. Similarly, the proportion of infants with abnormal neurobehavioral scores was significantly higher in the IUGR subgroup with abnormal MCA Doppler parameters in the areas of habituation, social-interactive, motor system and attention.

CONCLUSION

Abnormal MCA Doppler findings are predictive of neurobehavioral impairment among preterm newborns with IUGR, which suggests that this reflects an advanced stage of brain injury with a higher risk of abnormal neurological maturation.

Neonatal neurobehavioral organization after exposure to maternal epidural analgesia in labor

OBJECTIVE

To explore relationships between maternal epidural analgesia and two measures of neurobehavioral organization in infants at the initial feeding 1 hour after birth.

DESIGN

Prospective comparative design.

SETTING

Inner-city community hospital, Chicago, Illinois.

PARTICIPANTS

Convenience sample of 52 low-risk, mainly Black and Latino, mother/infant dyads.

METHODS

Mothers self-selected to labor with epidural or no labor pain medication. Neonatal neurobehavioral organization was measured in term infants at the initial feeding 1 hour after birth. A nutritive sucking apparatus generated data on total number of sucks and sucking pressure. Video recordings of infants (before and after the initial feeding) were coded for behavioral states, with analysis on frequency of alertness.

RESULTS

Total number of sucks and sucking pressure were not related to epidural exposure, although an epidural drug dosage effect on total number of sucks was evident when gender was a factor. Unmedicated girls demonstrated more sucks than girls in the high-dosage epidural group (p=.027). Overall, girls exhibited stronger sucking pressure than boys (p=.042). Frequency of alertness was not related to epidural exposure, although longer labor was related to greater alertness (p=.003), and Latino infants were more alert than Black infants (p=.002).

CONCLUSIONS

Results suggest attenuated neonatal nutritive sucking organization in girls after exposure to high maternal epidural dosages. In comparison to boys, girls may have enhanced neurobehavioral organization at birth. Race/ethnicity and alertness may have spurious associations in which hidden factors drive the relationship.

Does maternal anxiety affect neonatal behaviour differently in boys and girls?

The aim of this work is to study whether maternal anxiety is related to different neonatal behaviour in boys and girls. In boys (n=128), maternal anxiety is related to lower state organization and to increased autonomic stability. Girls' (n=131) behaviour is not related to maternal anxiety.

Cerebral blood perfusion and neurobehavioral performance in full-term small-for-gestational-age fetuses

OBJECTIVE

The purpose of this study was to evaluate changes in cerebral blood perfusion and middle cerebral artery (MCA) Doppler in full-term small-for-gestational-age fetuses (SGA) and to explore their association with neonatal neurobehavioral performance.

STUDY DESIGN

Frontal brain perfusion that was measured by fractional moving blood volume (FMBV) and MCA Doppler pulsatility index were assessed in 60 SGA fetuses with normal umbilical artery Doppler results that were matched with adequate-for-gestational-age fetuses. Neonates were evaluated with the Neonatal-Behavioral-Assessment-Scale (NBAS).

RESULTS

The proportion of SGA fetuses with increased FMBV (35% vs 5%; P < .001) and decreased MCA Doppler pulsatility index (15% vs 1.7%; P < .01) was significantly higher. SGA fetuses showed poorer NBAS scores in all areas. Increased FMBV identified SGA fetuses with the highest risks of abnormal NBAS in social-interactive (odds ratio, 7.8), attention (odds ratio, 22.8), and state-organization (odds ratio, 25.0). Abnormal MCA Doppler identified SGA with abnormal scores in motor area (odds ratio, 10.7).

CONCLUSION

Increased brain blood perfusion discriminates SGA fetuses that are at risk for abnormal neurobehavior.