Describing the Shape of the Relationship Between Gestational Age at Birth and Cognitive Development in a Nationally Representative U.S. Birth Cohort

Sex-specific associations between maternal thyroid peroxidase antibodies and cognitive development in preschool children: A prospective cohort study

BACKGROUND

An association between maternal thyroid dysfunction throughout pregnancy and subsequent risk of neurodevelopmental abnormalities in offspring has been demonstrated. However, the potential effects of maternal thyroid autoimmunity on neurodevelopment in the absence of maternal hypothyroidism remain unclear. Therefore, in this study, we explored the association between maternal thyroid peroxidase antibody (TPOAb) positivity and cognitive development in preschool children.

METHODS

A total of 1849 mother-child pairs were recruited from the Ma'anshan Birth Cohort Study. During the follow-up period, an electrochemiluminescence immunoassay was used to retrospectively measure serum TPOAb levels in pregnant women. The cognitive development of preschool children was evaluated by using the Chinese version of the Wechsler Preschool and Primary Scale of Intelligence-Fourth Edition. A growth mixture model was used to fit the trajectory of TPOAb. Multiple linear regression and logistic regression models were used to explore the associations between the developmental trajectory of TPOAb-positivity at different gestational periods and the cognitive development of preschool children by sex.

RESULTS

A total of 1849 mother-child pairs (mean [SD] age: 26.7 [3.6] years) were enrolled in the final study. Maternal TPOAb positivity in the first trimester was associated with a risk of below-average processing speed index in girls (OR: 2.07; 95% CI 1.06-4.01) and below-average full-scale intelligence quotient (FSIQ) in boys (OR: 2.36; 95% CI: 1.10-5.05). Maternal TPOAb positivity in the third trimester was associated with below-average working memory (WMI) (OR: 2.51; 95% CI: 1.02-6.20) in girls. In girls, the WMI (β = -3.17, 95% CI: -5.82--0.52), fluid reasoning index (FRI) (β = -4.49, 95% CI: -7.18--1.80), and FSIQ score (β = -2.43, 95% CI: -4.77--0.08) decreased, whereas in mothers, the level of lgTPOAb increased during pregnancy.

CONCLUSIONS

Positive maternal thyroid peroxidase antibody levels during pregnancy may be associated with poorer cognitive development in preschool children. These findings require independent confirmation in other populations.

Spillover effects of gestational age on sibling's literacy

Adverse health events within families can harm children's development, including their early literacy. Using data from a longitudinal Wisconsin birth cohort, we estimated the spillover effect of younger siblings' gestational ages on older siblings' kindergarten-level literacy. We sampled 20,014 sibling pairs born during 2007-2010 who took Phonological Awareness Literacy Screening-Kindergarten tests during 2012-2016. Exposures were gestational age (completed weeks), preterm birth (gestational age <37 weeks), and very preterm birth (gestational age <32 weeks). We used gain-score regression-a fixed effects strategy-to estimate spillover effect. A one-week increase in younger siblings' gestational age improved the older siblings' test score by 0.011 SD (95% confidence interval: 0.001, 0.021 SD). The estimated spillover effect was larger among siblings whose mothers reported having a high school diploma/equivalent only (0.024 SD; 95% CI: 0.004, 0.044 SD). The finding underscores the networked effects of one individual's early-life health shocks on their family members.

Risk of Developmental Disorders in Children Born at 32 to 38 Weeks' Gestation: A Meta-Analysis

CONTEXT

Very preterm birth (<32 weeks) is associated with increased risk of developmental disorders. Emerging evidence suggests children born 32 to 38 weeks might also be at risk.

OBJECTIVES

To determine the relative risk and prevalence of being diagnosed with, or screening positive for, developmental disorders in children born moderately preterm, late preterm, and early term compared with term (≥37 weeks) or full term (39-40/41 weeks).

DATA SOURCES

Medline, Embase, Psychinfo, Cumulative Index of Nursing, and Allied Health Literature.

STUDY SELECTION

Reported ≥1 developmental disorder, provided estimates for children born 32 to 38 weeks.

DATA EXTRACTION

A single reviewer extracted data; a 20% sample was second checked. Data were pooled using random-effects meta-analyses.

RESULTS

Seventy six studies were included. Compared with term born children, there was increased risk of most developmental disorders, particularly in the moderately preterm group, but also in late preterm and early term groups: the relative risk of cerebral palsy was, for 32 to 33 weeks: 14.1 (95% confidence intervals [CI]: 12.3-16.0), 34 to 36 weeks: 3.52 (95% CI: 3.16-3.92) and 37 to 38 weeks: 1.44 (95% CI: 1.32-1.58).

LIMITATIONS

Studies assessed children at different ages using varied criteria. The majority were from economically developed countries. All were published in English. Data were variably sparse; subgroup comparisons were sometimes based on single studies.

CONCLUSIONS

Children born moderately preterm are at increased risk of being diagnosed with or screening positive for developmental disorders compared with term born children. This association is also demonstrated in late preterm and early term groups but effect sizes are smaller.

Gestational age and socio-demographic factors associated with school performance at the age of 12 years, a population-based study

BACKGROUND

Gestational age is positively associated with cognitive development, but socio-demographic factors also influence school performance. Previous studies suggested possible interaction, putting children with low socio-economic status (SES) at increased risk of the negative effects of prematurity.

OBJECTIVES

To investigate the association between gestational age in weeks, socio-demographic characteristics, and school performance at the age of 12 years among children in regular primary education.

METHODS

Population-based cohort study among liveborn singletons (N = 860,332) born in the Netherlands in 1999-2006 at 25-42 weeks' gestation, with school performance from 2011 to 2019. Regression analyses were conducted investigating the association of gestational age and sociodemographic factors with school performance and possible interaction.

RESULTS

School performance increased with gestational age up to 40 weeks. This pattern was evident across socio-demographic strata. Children born at 25 weeks had -0.57 SD (95% confidence interval -0.79, -0.35) lower school performance z-scores and lower secondary school level compared to 40 weeks. Low maternal education, low maternal age, and non-European origin were strongly associated with lower school performance. Being born third or later and low socioeconomic status (SES) were also associated with lower school performance, but differences were smaller than among other factors. When born preterm, children from mothers with low education level, low or high age, low SES or children born third or later were at higher risk for lower school performance compared to children of mothers with intermediate education level, aged 25-29 years, with intermediate SES or first borns (evidence of interaction).

CONCLUSIONS

Higher gestational age is associated with better school performance at the age of 12 years along the entire spectrum of gestational age, beyond the cut-off of preterm birth and across socio-demographic differences. Children in socially or economically disadvantaged situations might be more vulnerable to the negative impact of preterm birth. Other important factors in school performance are maternal education, maternal age, ethnicity, birth order and SES. Results should be interpreted with caution due to differential loss to follow-up.

Associations of preterm and early-term birth with suspected developmental coordination disorder: a national retrospective cohort study in children aged 3-10 years

BACKGROUND

This study analyzed the motor development and suspected developmental coordination disorder of very and moderately preterm (< 34+0 gestational age), late preterm (34+0-36+6 gestational week), and early-term (37+0-38+6 gestational week) children compared to their full-term peers with a national population-based sample in China.

METHODS

A total of 1673 children (799 girls, 874 boys) aged 3-10 years old were individually assessed with the Movement Assessment Battery for Children-second edition (MABC-2). The association between gestational age and motor performance of children was analyzed using a multilevel regression model.

RESULTS

The global motor performance [β =  - 5.111, 95% confidence interval (CI) =  - 9.200 to - 1.022; P = 0.015] and balance (β =  - 5.182, 95% CI =  - 5.055 to - 1.158; P = 0.003) for very and moderately preterm children aged 3-6 years old were significantly lower than their full-term peers when adjusting for confounders. Late preterm and early-term children showed no difference. Moreover, very and moderately preterm children aged 3-6 years had a higher risk of suspected developmental coordination disorder (DCD) (≤ 5 percentile of MABC-2 score) when adjusting for potential confounders [odds ratio (OR) = 2.931, 95% CI = 1.067-8.054; P = 0.038]. Late preterm and early-term children showed no difference in motor performance from their full-term peers (each P > 0.05).

CONCLUSIONS

Our findings have important implications for understanding motor impairment in children born at different gestational ages. Very and moderately preterm preschoolers have an increased risk of DCD, and long-term follow-up should be provided for early detection and intervention.

Associations between early efficiency in language processing and language and cognitive outcomes in children born full term and preterm: similarities and differences

Associations between children's early language processing efficiency and later verbal and non-verbal outcomes shed light on the extent to which early information processing skills support later learning across different domains of function. Examining whether the strengths of associations are similar in typically developing and at-risk populations provides an additional lens into the varying routes to learning that children may take across development. In this follow-up study, children born full-term (FT, n = 49) and preterm (PT, n = 45, ≤32 weeks gestational age, birth weight <1800 g) were assessed in the Looking While Listening (LWL) task at 18 months (corrected for degree of prematurity in PT group). This eye-tracking task assesses efficiency of real-time spoken language comprehension as accuracy and speed (RT) of processing. At 4 ½ years, children were assessed on standardized tests of receptive vocabulary, expressive language, and non-verbal IQ. Language processing efficiency was associated with both language outcomes (r²-change: 7.0-19.7%, p < 0.01), after covariates. Birth group did not moderate these effects, suggesting similar mechanisms of learning in these domains for PT and FT children. However, birth group moderated the association between speed and non-verbal IQ (r²-change: 4.5%, p < 0.05), such that an association was found in the PT but not the FT group. This finding suggests that information processing skills reflected in efficiency of real-time language processing may be recruited to support learning in a broader range of verbal and non-verbal domains in the PT compared to the FT group.

Associations of early-life exposures and socioeconomic status with cognitive development at preadolescence

BACKGROUND

The long-term relations of socioeconomic status (SES) and early-life exposures with cognitive development at preadolescence are not fully understood, especially in low SES populations. We examined associations of SES and early-life exposures including feeding practices, physical growth and infections with cognitive development among preadolescents from underprivileged communities.

METHODS

A prospective study was conducted among 146 healthy children from two relatively low SES Arab villages in Israel, who were recruited at age 1-9 weeks and followed until age 18 months. Information was obtained on their feeding practices, health status and growth indicators. Cognitive development at age 10-12 years was assessed using the Wechsler Intelligence Scale, including the full-scale intelligence quotient (FSIQ) and scores of four cognitive domains. Multiple linear regression models were performed.

RESULTS

Nearly all the children (98%) were breastfed in infancy. Bivariate correlations were found of SES, growth indices and rates of diarrheal and respiratory illnesses in infancy, but not of feeding practices, with cognitive scores. In multivariable models, SES was positively (p < 0.001) associated with all the cognitive domains (beta coefficient ranges 4.3 to 8.2). Birthweight was positively associated with FSIQ (p = 0.039) and the perceptual reasoning index (p = 0.002). Weight for age Z score at age 10-14 months was positively associated with the verbal comprehension index (p = 0.003). The rate of respiratory illnesses was negatively associated with the perceptual reasoning index (p = 0.05).

CONCLUSION

SES is strongly associated with cognitive development even in relatively low SES communities. Birthweight, weight indicators and respiratory illness in infancy might affect cognitive development through preadolescence.

Association of Gestational Age at Birth With Subsequent Suspected Developmental Coordination Disorder in Early Childhood in China

IMPORTANCE

It remains unknown whether children born at different degrees of prematurity, early term, and post term might have a higher risk of developmental coordination disorder (DCD) compared with completely full-term children (39-40 gestational weeks).

OBJECTIVE

To differentiate between suspected DCD in children with different gestational ages based on a national representative sample in China.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study was conducted in China from April 1, 2018, to December 31, 2019. A total of 152 433 children aged 3 to 5 years from 2403 public kindergartens in 551 cities of China were included in the final analysis. A multilevel regression model was developed to determine the strength of association for different gestational ages associated with suspected DCD when considering kindergartens as clusters.

MAIN OUTCOMES AND MEASURES

Children's motor performance was assessed using the Little Developmental Coordination Disorder Questionnaire, completed by their parents. Gestational age was determined according to the mother's medical records and divided into 7 categories: completely full term (39 to 40 weeks' gestation), very preterm (<32 weeks), moderately preterm (32-33 weeks), late preterm (34-36 weeks), early term (37-38 weeks), late term (41 weeks), and post term (>41 weeks).

RESULTS

A total of 152 433 children aged 3 to 5 years (mean [SD] age, 4.5 [0.8] years), including 80 370 boys (52.7%) and 72 063 girls (47.3%), were included in the study. There were 45 052 children (29.6%) aged 3 years, 59 796 (39.2%) aged 4 years, and 47 585 (31.2%) aged 5 years. Children who were born very preterm (odds ratio [OR], 1.35; 95% CI, 1.23-1.48), moderately preterm (OR, 1.18; 95% CI, 1.02-1.36), late preterm (OR, 1.24; 95% CI, 1.16-1.32), early term (OR, 1.11; 95% CI, 1.06-1.16), and post term (OR, 1.17; 95% CI, 1.07-1.27) were more likely to be classified in the suspected DCD category on the Little Developmental Coordination Disorder Questionnaire than completely full-term children after adjusting for the same characteristics. Additionally, there was no association with suspected DCD in younger (aged 3 years) early-term and postterm children by stratified analyses.

CONCLUSIONS AND RELEVANCE

In this cohort study, every degree of prematurity at birth, early-term birth, and postterm birth were associated with suspected DCD when compared with full-term birth. These findings have important implications for understanding motor development in children born at different gestational ages. Long-term follow-up and rehabilitation interventions should be considered for children born early and post term.

Association between early-term birth and delayed neurodevelopment at the age of 2 years: results from a cohort study in China

A growing body of evidence indicates that early-term births (37-38 weeks of gestational age) have an increased risk of short-term and long-term complications. Here, we sought to explore the association between early-term births and the risk of delayed neurodevelopment at age 2 years. Pregnant women and their live singleton birth were recruited from a single tertiary hospital between October 2013 and February 2017. Mental and Psychomotor Development Indexes (MDI and PDI) were assessed using the Bayley Scales of Infant Development (BSID). Delayed neurodevelopment was defined as scores of PDI or MDI less than -1SD relative to the mean score of the study population. In total, 1678 full-term infants and 727 early-term infants were assessed when they were 2 years old. After adjustment for potential confounders, early-term birth was related to 43% increased odds of neurodevelopmental delay in the PDI domain as compared with full-term birth (OR: 1.43; 95% CI: 1.12, 1.82). The observed associations were more prominent among those infants born by cesarean (OR: 1.44; 95% CI: 1.03, 2.00) and among males (OR: 1.66; 95% CI: 1.20, 2.28). No statistical difference in the MDI domain was found between early-term and full-term births.Conclusions: Our findings suggest that early-term birth was associated with increased odds of delayed neurodevelopment in the PDI domain as measured by BSID assessments at age 2 years. Health professionals should be aware of the influence of early-term birth on the risk of delayed neurodevelopment. What is Known: • Evidence indicates that early-term births have an increased risk of short-term and long-term complications. • The association between early-term births and delayed neurodevelopment at their early childhood has not been widely studied. What is New: • Early-term birth was associated with increased odds of delayed neurodevelopment in PDI domain as measured by BSID assessments at age 2 years. • The observed associations were more prominent among infants born by cesarean section and among male infants.

Gestational Age at Term and Educational Outcomes at Age Nine

OBJECTIVES

To estimate associations between gestational age (GA) and teacher-reported academic outcomes at age 9 years among children born at term (37-41 weeks).

METHODS

A secondary data analysis of 1405 children participating in a national US birth cohort study was conducted. At age 9 years, students were evaluated by their teachers in the areas of mathematics, science and social studies, and language and literacy. Unadjusted and adjusted logistic regression models of associations between GA and teacher-reported academic outcomes were estimated and neonatal morbidities were explored as potential pathways.

RESULTS

A continuous measure of GA in weeks was significantly associated with above-average rankings in all areas. The associations were similar across outcomes (eg, mathematics [odds ratio (OR): 1.13; confidence interval (CI): 1.02-1.25], science and social studies [OR: 1.13; CI: 1.01-1.26], and language and literacy [OR: 1.16; CI: 1.05-1.28]) in a model that adjusted for child sex, maternal characteristics, and obstetric risk factors and delivery complications. Other specifications indicate a positive association between late term (41 weeks) and mathematics and a negative association between early term (37-38 weeks) and language and literacy, compared with term (39-40). The associations did not appear to operate through neonatal morbidity.

CONCLUSIONS

The findings highlight the importance of GA, even at term. Whereas current guidelines suggest waiting until at least 39 weeks to deliver when possible, our findings add to a small group of studies suggesting that GA through 41 weeks is associated with improvements in some educational outcomes.

Gestational Age at Birth and Risk of Developmental Delay: The Upstate KIDS Study

OBJECTIVE

The aim of this study is to model the association between gestational age at birth and early child development through 3 years of age.

STUDY DESIGN

Development of 5,868 children in Upstate KIDS (New York State; 2008-2014) was assessed at 7 time points using the Ages and Stages Questionnaire (ASQ). The ASQ was implemented using gestational age corrected dates of birth at 4, 8, 12, 18, 24, 30, and 36 months. Whether children were eligible for developmental services from the Early Intervention Program was determined through linkage. Gestational age was based on vital records. Statistical models adjusted for covariates including sociodemographic factors, maternal smoking, and plurality.

RESULTS

Compared with gestational age of 39 weeks, adjusted odds ratios (aOR) and 95% confidence intervals of failing the ASQ for children delivered at <32, 32-34, 35-36, 37, 38, and 40 weeks of gestational age were 5.32 (3.42-8.28), 2.43 (1.60-3.69), 1.38 (1.00-1.90), 1.37 (0.98-1.90), 1.29 (0.99-1.67), 0.73 (0.55-0.96), and 0.51 (0.32-0.82). Similar risks of being eligible for Early Intervention Program services were observed (aOR: 4.19, 2.10, 1.29, 1.20, 1.01, 1.00 [ref], 0.92, and 0.78 respectively for <32, 32-34, 37, 38, 39 [ref], 40, and 41 weeks).

CONCLUSION

Gestational age was inversely associated with developmental delays for all gestational ages. Evidence from our study is potentially informative for low-risk deliveries at 39 weeks, but it is notable that deliveries at 40 weeks exhibited further lower risk.

Postpartum depression and infant development up to 24 months: A nationwide population-based study

AIMS

Postpartum depression (PPD) is the most common complication women experience after delivery. We aimed to examine the association of maternal PPD with delays in child development, in a population-based study, in the first two years of life.

METHODS

A nation-wide population-based historical cohort study in the setting of the Mother and Child Health Clinics in Israel, where infants are routinely evaluated for growth and development. Data were retrieved on 96,623 infants born in 2014-2015 whose mothers had PPD screening. Logistic regressions were used to estimate the associations of PPD with the achievements of developmental milestones, controlling for potential confounders.

RESULTS

PPD was identified in 4,268 mothers (4.7%). PPD was associated with delays in language skills, including the production of voices in dialogue (OR=1.88, 95% CI: 1.41-2.52) and speaking 2-3 words (OR=1.24, 95% CI: 1.13-1.37). PPD was associated with about 1.5 times increased odds of delays in personal-social skills, including reacting to voices (OR=1.43, 95% CI: 1.22-1.67) and pointing to selected objects (OR=1.47 95% CI: 1.10-1.97). Associations were also seen with delays in fine motor and adaptive skills, such as pinching (OR=1.50, 95% CI: 1.20-1.86), and gross motor skills, such as ground crawling (OR=1.36, 95% CI: 1.15-1.60).

CONCLUSIONS

In this population-based large cohort study, PPD as estimated in a national screening program, was associated with delays in early child development, which were shown in all assessed domains. Future studies should confirm our results and intervention programs should be developed to effectively minimize these gaps.

Early-term elective Caesarean sections did not increase the risk of behavioural problems at six to eight years of age

AIM

Our aim was to explore the under-researched associations between an elective Caesarean section (C-section) at early-term or full-term gestation and behaviour at 6-8 years of age.

METHODS

We identified 1220 eligible children born by elective C-sections at Danish hospital from 2009 to 2011. Their mothers were randomised to elective C-sections at either 38+3 (early-term) or 39+3 (full-term) weeks of gestation. From December 2017 to August 2018, the parents completed the Strengths and Difficulties Questionnaire. The results were adjusted for maternal education, parity and the child's sex.

RESULTS

Of the 574 (45%) children followed up, 288 were delivered early-term and 286 were delivered full-term. The groups had similar baseline characteristics. There were no differences in the total difficulties score, subscale scores or the risk of being classified as having a possible or probable psychiatric disorder. Early-term boys had a lower risk of being classified as having a possible or probable psychiatric disorder and early-term girls had higher risk, but the results were not statistically significant.

CONCLUSION

We found no difference in behaviour at 6-8 years of age between children born by elective C-section at early- versus full-term gestation.

Neonatal Adverse Outcomes, Neonatal Birth Risks, and Socioeconomic Status: Combined Influence on Preterm Infants' Cognitive, Language, and Motor Development in Brazil

BACKGROUND

This study extended previous research by investigating the combined effects of neonatal birth risks, neonatal adverse outcomes, and socioeconomic status on preterm neurodevelopment.

METHOD

A total of 184 preterm infants were assessed using the Bayley Scales of Infant Development III in a follow-up clinic in southern Brazil. Structural equation modeling was conducted with 3 latent variables (neonatal birth risks, neonatal adverse outcomes, and socioeconomic status) and 3 outcomes (cognitive, language, and motor development).

RESULTS

The analyses showed that neonatal adverse outcomes were associated with infants' cognitive (b = -0.45, P < .001), language (b = -0.23, P = .001), and motor (b = -0.51, P < .001) development. Socioeconomic status also explained the variances (cognitive: b = 0.20, P = .006; language: b = 0.28, P = .001; and motor: b = 0.21, P = .004), whereas neonatal birth risks remained significant only in the motor development (b = 0.15, P = .040).

CONCLUSION

This study suggests that the most evident contributors to poor neurodevelopment were adverse outcomes and socioeconomic risk factors.

Gestational age, kindergarten-level literacy, and effect modification by maternal socio-economic and demographic factors

BACKGROUND

Shorter gestational age at birth is associated with worse academic performance in childhood. Socio-economic and demographic factors that affect a child's development may modify the relationship between gestational age and later academic performance.

OBJECTIVE

The purpose of this study was to investigate socio-economic and demographic effect modification of gestational age's association with kindergarten-level literacy skills in a longitudinal Wisconsin birth cohort.

METHODS

We sampled 153 145 singleton births (2007-2010) that linked to Phonological Awareness Literacy Screening-Kindergarten (PALS-K) scores (2012-2016 school years). PALS-K outcomes included meeting the screening benchmark (≥28 points, range 0-102 points) and the standardised score. Multivariable linear regressions of PALS-K outcomes on gestational age (completed weeks) included individual interactions for five maternal attributes measured at delivery: Medicaid coverage, education, age, race/ethnicity, and marital status.

RESULTS

Each additional completed gestational week was associated with a 0.5 percentage point increase in the probability of meeting the PALS-K literacy benchmark. The benefit of an additional week of gestational age was 0.5 percentage points (95% confidence interval 0.3, 0.7 percentage points) greater for Medicaid-covered births (0.8 percentage points) relative to non-Medicaid births (0.3 percentage points). Relative to only completing high school, having college education weakened this association by 0.3-0.6 percentage points, depending on years in college. Similar but modest relations emerged with standardised scores.

CONCLUSIONS

Socio-economic advantage as indicated by non-Medicaid coverage or higher levels of completed maternal education may diminish the cost of preterm birth on a child's kindergarten-level literacy skills.

Sitting Matters! Differences Between Sitters and Nonsitters at 6 Months' Adjusted Age in Infants At-Risk and Born Preterm

PURPOSE

Sitting delays in infants born preterm compound cognitive and language deficits. This retrospective study examines differences in prematurity-related risk and compares developmental outcomes between sitters and nonsitters at 6 months' adjusted age.

METHODS

A total of 105 graduates of the neonatal intensive care unit met inclusion criteria. Infant demographic and medical risk profiles and 6-month Bayley Scales of Infant Development-3rd edition (BSID-III) cognitive and language scores were retrieved. Infants who sat with hands free greater than 60 seconds were classified as "sitters."

RESULTS

Sixty-nine percent of the sample were nonsitters and were born earlier, had lower birth weights, were chronologically older at follow-up, and spent more days with respiratory support. BSID-III scores were significantly higher in sitters but did not differ by gender, multiple birth, head ultrasound results, payment type, or race/ethnicity.

CONCLUSION

Sitting abilities at 6 months' adjusted age are associated with prematurity risk factors. Cognitive and language scores differ significantly between sitters and nonsitters.

Differentiating the cognitive development of early-term births in infants and toddlers: a cross-sectional study in China

OBJECTIVES

This study aimed to explore the cognitive development of low-risk children during early childhood for early-term births at 37 and 38 weeks of gestation compared with full term births at 39-41 weeks of gestation.

SETTING AND PARTICIPANTS

We conducted a cross-sectional study in Shanghai, one of the largest cities in China. A total of 1444 children from singleton pregnancies born at term gestation were included in the study.

MEASURES

The cognitive outcomes of the subjects were measured using the cognitive subtest of Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III) across three cities in China. We analysed the association between gestational age and cognitive development during infancy and toddler stages using multivariate linear modelling.

RESULTS

The cognitive development scores for infants born at 37 gestational weeks were significantly lower than those born at 39-41 gestational weeks (β=-2.257, 95% CI -4.280 to -0.235; p<0.05) after adjusting for children's and maternal characteristics, as well as socio-economic factors. However, there were no significant differences in cognitive ability between infants born at 38 gestational weeks compared with their full-term counterparts (p>0.05). Moreover, these effects were not found in toddlers (between 17 and 48 months of age) after adjusting for the possible confounders (p>0.05).

CONCLUSIONS

Infants born at 37 weeks of gestation exhibited weaker cognitive ability compared with those born at 39-41 weeks of gestation. Our findings provide evidences for the close monitoring of potential developmental problems in early-term children, especially those born at 37 gestational weeks.

Is it possible to safely prevent late preterm and early term births?

Late preterm and early term birth is associated with adverse short- and long-term consequences, particularly for neurodevelopment. A clear reduction in these births can be achieved by avoidance of non-medically indicated births prior to 39 weeks gestation, as shown following the introduction of prohibitive policies in the USA. However, clinicians and policy-makers must always consider the potential for unintended adverse consequences of such action, such as a potential for an increase in term stillbirth. Finding the balance between optimising long-term neurological outcomes and avoiding rare but devastating term stillbirths is one of the challenges of modern maternity care. In this article we review the current evidence for whether this balance can be found, where early births can be safely prevented, and what remains to be addressed to optimise this balance safely.

Neuropsychological assessment of Chilean children with a history of extreme prematurity: An exploratory study

This study was conducted to explore the neuropsychological abilities of premature Chilean children. Two groups (Premature and Control, 10 children each, age ranging from 5 to 7.11) were established based on weeks of gestation and/or weight at birth. Relevant variables such as age, gender, schooling, and socioeconomic level were matched considering Chile's particular demographic context. Children were assessed by means of the Evaluación Neuropsicológica Infantil (ENI-2) battery, measuring nine cognitive domains encompassing 23 subscales. In turn, subscales are grouped in two scales: Cognitive Functions and Executive Functions. Since the ENI-2 battery provides norms for Spanish-speaking children, obtained data were inspected both for possible between-group differences and either adjustment or deviance from average range. Results show that premature children perform within typical ranges in all subscales except for Visual attention and Graphic fluency. When comparing both groups, some differences emerged. These differences are most prominent in subscales related to visuoperceptual skills. Interestingly, between-group linguistic performance is very similar. The point is made that early linguistic interventions conducted on premature children seem to positively impact on oral language expression and comprehension. On the contrary, early interventions focused on visuospatial abilities did not seem to attain the same impact. This may be a consequence of visual-information processing problems derived from cortical dorsal stream's vulnerability, which literature correlates with prematurity.

Investigating the association between post-term birth and long term cognitive, developmental and educational impacts: a systematic review and Meta-analysis

Purpose: Infants who remain in-utero after their due date are exposed to increasing risk of infection, late stillbirth and delivery complications. Much of the current literature on post-term outcomes is based on short term observations and the impacts may be substantially greater in the long term. The aim of this work is to perform a systematic review and meta-analysis to quantify the cognitive or educational impacts of post term delivery.Methods: Systematic review was performed by the two authors using Medline database (1960-2017). A title search was performed to identify likely relevant literature. Exposure terms were clarified to identify papers where the exposure was related to delivery after the infants' due date. Primary outcome was cognitive score. A quality assessment and data extraction pro forma was completed by both reviewers for all studies deemed to satisfy the inclusion and exclusion criteria. Meta-analysis used adjusted results where available. Small-study bias was assessed visually using a funnel plot and then formally tested using Egger's regression asymmetry test.Results: Medline was searched on the 4 July 2018; and produced a list of 1318 publications. Of these, 43 abstracts were screened, and of these a total of 10 full-text papers were reviewed. A further three papers were identified during this review and contributed to a total of 13 papers. The publications dated from 1969 to 2017. Two studies presented a binary outcome for cognitive measures and combined estimates found that the risk of a low cognitive score was higher in post-term infants compared to term infants (odds ratio [OR] 1.06 [1.04-1.08]). Four papers presented the association with mean cognitive measures and post-term delivery, and all demonstrated a mean reduction in scores in the post-term group. A combined estimate showed strong evidence of a reduction in cognitive scores across the four studies (-1.90 [-3.50 to -0.31]). There was little evidence of heterogeneity in the studies which reported cognitive outcomes (other p-values >.2).Conclusion: This meta-analysis has found that post term birth (>41 + 6 weeks) is associated with small but significant negative effects on cognitive outcomes when compared with delivery at, or around term. The effect, while small, is compounded by a common exposure and appears consistent in the studies identified. Less evidence was found for a measurable impact on early developmental measures or educational outcomes. This may further help inform the debate on the timing of otherwise uncomplicated pregnancies and further trials in this area.

Gestational Age and Child Development at Age Five in a Population-Based Cohort of Australian Aboriginal and Non-Aboriginal Children

BACKGROUND

Preterm birth and developmental vulnerability are more common in Australian Aboriginal compared with non-Aboriginal children. We quantified how gestational age relates to developmental vulnerability in both populations.

METHODS

Perinatal datasets were linked to the Australian Early Development Census (AEDC), which collects data on five domains, including physical, social, emotional, language/cognitive, and general knowledge/communication development. We quantified the risk of developmental vulnerability on ≥1 domains at age 5, according to gestational age and Aboriginality, for 97 989 children born in New South Wales, Australia, who started school in 2009 or 2012.

RESULTS

Seven thousand and seventy-nine children (7%) were Aboriginal. Compared with non-Aboriginal children, Aboriginal children were more likely to be preterm (5% vs. 9%), and developmentally vulnerable on ≥1 domains (20% vs. 36%). Overall, the proportion of developmentally vulnerable children decreased with increasing gestational age, from 44% at ≤27 weeks to 20% at 40 weeks. Aboriginal children had higher risks than non-Aboriginal children across the gestational age range, peaking among early term children (risk difference [RD] 19.0, 95% confidence interval [CI] 16.3, 21.7; relative risk [RR] 1.91, 95% CI 1.77, 2.06). The relation of gestational age to developmental outcomes was the same in Aboriginal and non-Aboriginal children, and adjustment for socio-economic disadvantage attenuated the risk differences and risk ratios across the gestational age range.

CONCLUSIONS

Although the relation of gestational age to developmental vulnerability was similar in Aboriginal and non-Aboriginal children, Aboriginal children had a higher risk of developmental vulnerability at all gestational ages, which was largely accounted for by socio-economic disadvantage.

Gestational age at birth and behavioral problems from four to 11 years of age: birth cohort study

BACKGROUND

Studies conducted mainly in high-income countries have shown that preterm births are associated with increased risk of behavioral problems and psychiatric disorders. The aim of this study was to assess the prevalence of behavioral problems from middle-childhood to early-adolescence according to gestational age at birth in a middle-income setting.

METHODS

A population-based birth cohort (n = 4231) in Pelotas, Brazil, was followed-up in several occasions from birth to 11 years. Estimated GA was based on last menstrual period or, when unknown or inconsistent, on the Dubowitz method. Behavioral problems were assessed at 4 (Child Behavior Checklist - CBCL), and at 6 and 11 years (Development and Well-Being Assessment - DAWBA) tool. Maternal socio-economic characteristics and depression at 2, 4 and 6 years post-partum, child perinatal characteristics and breastfeeding duration were used as confounders. Analyses were run by linear and logistic regression.

RESULTS

Three thousand two hundred four children had full information on gestational age, CBCL and DAWBA. At 4 years, mean total (42.9 ± 24.0) and mean externalizing (18.8 ± 9.1) CBCL scores were higher among preterm girls born at <34 weeks than among full term girls (33.2 ± 15.1 and 15.0 ± 6.6, respectively). After controlling for confounders the association was no longer significant. At the age of 6 years there was no association between gestational age and behavior, neither in crude nor in adjusted analyses. Odds ratio for any psychiatric disorders at 11 years was 60% (1.6; 1.1-2.1) higher among those born at 34-36 weeks than in full-term children, but the association disappeared in adjusted analyses.

CONCLUSION

At this large cohort, behavioral problems from middle-childhood to early-adolescence are more related to family socio-economic characteristics and to other child perinatal conditions than to gestational age at birth.

Educational Performance of Children Born Prematurely

IMPORTANCE

Survivors of preterm birth often present with medical morbidities; however, variation in their long-term educational performance has not been well described.

OBJECTIVE

To estimate the association between gestational age and 4 outcomes in school-aged children: readiness to enter kindergarten, scores on standardized tests in elementary and middle school, gifted status, and low performance.

DESIGN, SETTING, AND PARTICIPANTS

In a retrospective cohort study, children born in Florida between 1992 and 2002 at 23 to 41 weeks' gestation who entered Florida's public schools between 1995 and 2012 were assessed for kindergarten readiness and tested in mathematics and reading in grades 3 through 8. Data analysis was performed from January 12, 2016, to March 1, 2017.

EXPOSURES

Gestational age at birth.

MAIN OUTCOMES AND MEASURES

Kindergarten readiness, scores on the Florida Comprehensive Achievement Test (FCAT), classified as gifted, and classified as low performance.

RESULTS

A total of 1 527 113 singleton infants with gestational ages of 23 to 41 weeks born between 1992 and 2002 were matched to Florida public school records. Of these, 1 301 497 children were included in the analysis; 641 479 (49.3%) were girls. A total of 301 (65.0%) Florida children born at 23 to 24 weeks' gestation were designated as ready to start kindergarten. When the FCAT test scores were adjusted for potentially confounding maternal and infant variables, children born at 23 to 24 weeks' gestation performed 0.66 SD (95% CI, -0.73 to -0.59) lower compared with those born at full term. A total of 123 554 (9.5%) of all Florida-born public school students were considered gifted, including 17 (1.8%) of those born at 23 to 24 weeks' gestation. In comparison, 75 458 (5.8%) of all Florida-born public school students were low performing; 310 (33.5%) of these children had been born at 23 to 24 weeks' gestation. Kindergarten readiness, FCAT scores, and gifted status were positively related to gestational age, whereas low performance was inversely related to gestational age.

CONCLUSIONS AND RELEVANCE

Although gestational age has long been associated with poor educational performance, a sufficient proportion of children born near the limits of viability performed within expected school norms, warranting further investigation into how and why certain children are able to overcome the educational burdens that may follow preterm birth.