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

Longer duration of gestation in term singletons is associated with better infant neurodevelopment

BACKGROUND

Longer gestation at term and post-term age is associated with increased perinatal mortality. Nonetheless, recent neuroimaging studies indicated that longer gestation is also associated with better functioning of the child's brain.

AIMS

to assess whether longer gestation in term and post-term (in short: term) singletons is associated with better infant neurodevelopment.

STUDY DESIGN

cross-sectional observational study.

SUBJECTS

Participants were all singleton term infants (n = 1563) aged 2-18 months of the IMP-SINDA project that collected normative data for the Infant Motor Profile (IMP) and Standardized Infant NeuroDevelopmental Assessment (SINDA). The group was representative of the Dutch population.

OUTCOME MEASURES

Total IMP score was the primary outcome. Secondary outcomes were atypical total IMP scores (scores <15th percentile) and SINDA's neurological and developmental scores.

RESULTS

Duration of gestation had a quadratic relationship with IMP and SINDA developmental scores. IMP scores were lowest at a gestation of 38·5 weeks, SINDA developmental scores at 38·7 weeks. Next, both scores increased with increasing duration of gestation. Infants born at 41-42 weeks had significantly less often atypical IMP scores (adjusted OR [95 % CI]: 0·571 [0·341-0·957] and atypical SINDA developmental scores (adjusted OR: 0·366 [0·195-0·688]) than infants born at 39-40 weeks. Duration of gestation was not associated with SINDA's neurological score.

CONCLUSIONS

In term singleton infants representative of the Dutch population longer gestation is associated with better infant neurodevelopment scores suggesting better neural network efficiency. Longer gestation in term infants is not associated with atypical neurological scores.

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.

Higher risk for poor handwriting in Taiwanese children born late preterm

BACKGROUND

Late-preterm and early-term births constitute a significant proportion of live births. However, handwriting skills of these two populations remain unclear. We aimed to investigate their risk for poor Chinese handwriting in grade two.

METHODS

In this observational study, 185 second graders born late preterm (34⁺⁰-36⁺⁶ weeks' gestation, n = 54), early term (37⁺⁰-38⁺⁶ weeks' gestation, n = 56), and full term (39⁺⁰-41⁺⁶ weeks' gestation, n = 75) without any intervention or diagnosis related to developmental delays were included. Their handwriting performance was rated by class teachers using the Chinese Handwriting Evaluation Form (CHEF), which is a standardized handwriting scale including five handwriting dimensions (construction, accuracy, directionality, speed, and pencil grasp).

RESULTS

After controlling for demographic risk factors, the late-preterm born group had a greater risk of having worse performance in the full form (adjusted odds ratio [aOR] = 3.93; p = .038) and construction dimension (aOR = 4.77; p = .009) of the CHEF than peers born at full term, whereas the risks were comparable for the early- and full-term born groups (aOR = 0.14-1.90; p = .073-0.453 in the handwriting dimensions).

CONCLUSIONS

Late-preterm but not early-term born children were found to be at higher risk for poor Chinese handwriting in grade two. They particularly have difficulty with spatial construction including size, spacing, and alignment of Chinese characters and components that may influence handwriting legibility.

Effects of gestational age at birth on perinatal structural brain development in healthy term-born babies

Infants born in early term (37-38 weeks gestation) experience slower neurodevelopment than those born at full term (40-41 weeks gestation). While this could be due to higher perinatal morbidity, gestational age at birth may also have a direct effect on the brain. Here we characterise brain volume and white matter correlates of gestational age at birth in healthy term-born neonates and their relationship to later neurodevelopmental outcome using T2 and diffusion weighted MRI acquired in the neonatal period from a cohort (n = 454) of healthy babies born at term age (>37 weeks gestation) and scanned between 1 and 41 days after birth. Images were analysed using tensor-based morphometry and tract-based spatial statistics. Neurodevelopment was assessed at age 18 months using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). Infants born earlier had higher relative ventricular volume and lower relative brain volume in the deep grey matter, cerebellum and brainstem. Earlier birth was also associated with lower fractional anisotropy, higher mean, axial, and radial diffusivity in major white matter tracts. Gestational age at birth was positively associated with all Bayley-III subscales at age 18 months. Regression models predicting outcome from gestational age at birth were significantly improved after adding neuroimaging features associated with gestational age at birth. This work adds to the body of evidence of the impact of early term birth and highlights the importance of considering the effect of gestational age at birth in future neuroimaging studies including term-born babies.

Gestational age at term delivery and children's neurocognitive development

BACKGROUND

Preterm birth is associated with lower neurocognitive performance. However, whether children's neurodevelopment improves with longer gestations within the full-term range (37-41 weeks) is unclear. Given the high rate of obstetric intervention in the USA, it is critical to determine whether long-term outcomes differ for children delivered at each week of term.

METHODS

This secondary analysis included 39 199 live-born singleton children of women who were admitted to the hospital in spontaneous labour from the US Collaborative Perinatal Project (1959-76). At each week of term gestation, we evaluated development at 8 months using the Bayley Scales of Infant Development, 4 years using the Stanford-Binet IQ (SBIQ) domains and 7 years using the Wechsler Intelligence Scales for Children (WISC) and Wide-Range Achievement Tests (WRAT).

RESULTS

Children's neurocognitive performance improved with each week of gestation from 37 weeks, peaking at 40 or 41 weeks. Relative to those delivered at 40 weeks, children had lower neurocognitive scores at 37 and 38 weeks for all assessments except SBIQ and WISC Performance IQ. Children delivered at 39 weeks had lower Bayley Mental (β = -1.18; confidence interval -1.77, -0.58) and Psychomotor (β = -1.18; confidence interval -1.90, -0.46) scores. Results were similar for within-family analyses comparing siblings, with the addition of lower WRAT scores at 39 weeks.

CONCLUSIONS

The improvement in development scores across assessment periods indicates that each week up to 40 or 41 weeks of gestation is important for short- and long-term cognitive development, suggesting 40-41 weeks may be the ideal delivery window for optimal neurodevelopmental outcomes.

Association of Gestational Age at Birth With Subsequent Neurodevelopment in Early Childhood: A National Retrospective Cohort Study in China

BACKGROUND

The association between preterm birth and neurodevelopmental delays have been well examined, however, reliable estimates for the full range of gestational age (GA) are limited, and few studies explored the impact of post-term birth on child development.

OBJECTIVE

This study aimed to examine the long-term neuropsychological outcomes of children born in a full range of GA with a national representative sample in China.

METHODS

In this retrospective population-based cohort study, a total of 137,530 preschoolers aged 3-5 years old (65,295/47.5% females and 72,235/52.5% males) were included in the final analysis. The Ages and Stages Questionnaires-Third Edition (ASQ-3) was completed by parents to evaluate children's neurodevelopment. The associations between GA and neurodevelopment were analyzed by a generalized additive mixed model with thin plate regression splines. Logistic regression was also conducted to examine the differences in children's development with different GAs.

RESULTS

There was a non-linear relationship between GA and children's neurodevelopmental outcomes with the highest scores at 40 weeks gestational age. The adjusted risks of GAs (very and moderately preterm, late-preterm, early-term, and post-term groups) on suspected developmental delays were observed in communication (OR were 1.83, 1.28, 1.13, and 1.21 respectively, each p < 0.05), gross motor skill (OR were 1.67, 1.38, 1.10, and 1.05 respectively, each p < 0.05), and personal social behavior (OR were 1.01, 1.36, 1.12, and 1.18 respectively, each p < 0.05). The adjusted OR of very and moderately preterm, late-preterm, and early-term were observed in fine motor skills (OR were 1.53, 1.22, and 1.09 respectively, each p < 0.05) and problem-solving (OR were 1.33, 1.12, and 1.06 respectively, each p < 0.05).

CONCLUSION

GAs is a risk factor for neurodevelopmental delays in preschoolers after controlling for a wide range of covariates, and 40-41 weeks may be the ideal delivery GA for optimal neurodevelopmental outcomes. Close observation and monitoring should be considered for early- and post-term born children as well as pre-term children.

[Neuropsychological development of late preterm infants and early term infants at the age of 1 year: a follow-up study]

OBJECTIVE

To study the level of neuropsychological development in late preterm infants and early term infants at the age of 1 year.

METHODS

A total of 1 257 children with a corrected age of 1 year were enrolled as subjects. According to gestational age at birth, they were divided into an early preterm group (28-33+6 weeks), a late preterm group (34-36+6 weeks), an early term group (37-38+6 weeks), and a full-term group (39-41+6 weeks). Gesell Developmental Schedules were used to assess the neuropsychological development of the children, and the groups were compared in terms of neuropsychological development at the age of 1 year.

RESULTS

There were significant differences in the developmental quotients of the five functional areas (adaptability, gross motor, fine motor, language and social ability) between the four groups at the age of 1 year (P<0.05), and the full-term infants had the highest development quotients, followed by the early term infants, the late preterm infants, and the early preterm infants (P<0.05). The full-term infants had the lowest rate of developmental delay in each functional area, while the early preterm infants had the highest rate (P<0.05). Compared with the full-term infants, the early term infants had a higher risk of developmental delay in adaptability (OR=1.796, P<0.05), and the late preterm infants had a higher risk of developmental delay in adaptability (OR=2.651, P<0.05) and fine motor (OR=2.679, P<0.05), while the early preterm infants had a higher risk of developmental delay in adaptability (OR=4.069, P<0.05), fine motor (OR=3.710, P<0.05), and social ability (OR=3.515, P<0.05).

CONCLUSIONS

The risk of neuropsychological developmental delay decreases with the increase in gestational age in children at the age of 1 year, with a dose-response effect. There are varying degrees of developmental delay in early term infants and late preterm infants, and health care follow-up for early term infants and late preterm infants should be taken seriously.

[Neuropsychological development of late preterm infants and early term infants at the age of 1 year: a follow-up study]

OBJECTIVE

To study the level of neuropsychological development in late preterm infants and early term infants at the age of 1 year.

METHODS

A total of 1 257 children with a corrected age of 1 year were enrolled as subjects. According to gestational age at birth, they were divided into an early preterm group (28-33⁺⁶ weeks), a late preterm group (34-36⁺⁶ weeks), an early term group (37-38⁺⁶ weeks), and a full-term group (39-41⁺⁶ weeks). Gesell Developmental Schedules were used to assess the neuropsychological development of the children, and the groups were compared in terms of neuropsychological development at the age of 1 year.

RESULTS

There were significant differences in the developmental quotients of the five functional areas (adaptability, gross motor, fine motor, language and social ability) between the four groups at the age of 1 year (P<0.05), and the full-term infants had the highest development quotients, followed by the early term infants, the late preterm infants, and the early preterm infants (P<0.05). The full-term infants had the lowest rate of developmental delay in each functional area, while the early preterm infants had the highest rate (P<0.05). Compared with the full-term infants, the early term infants had a higher risk of developmental delay in adaptability (OR=1.796, P<0.05), and the late preterm infants had a higher risk of developmental delay in adaptability (OR=2.651, P<0.05) and fine motor (OR=2.679, P<0.05), while the early preterm infants had a higher risk of developmental delay in adaptability (OR=4.069, P<0.05), fine motor (OR=3.710, P<0.05), and social ability (OR=3.515, P<0.05).

CONCLUSIONS

The risk of neuropsychological developmental delay decreases with the increase in gestational age in children at the age of 1 year, with a dose-response effect. There are varying degrees of developmental delay in early term infants and late preterm infants, and health care follow-up for early term infants and late preterm infants should be taken seriously.

Higher tactile sensitivity in preterm infants at term-equivalent age: A pilot study

Despite a growing body of research on perinatal sensory abilities, data on the extent of tactile sensitivity and more particularly passive touch (i.e. sensitivity to a stimulation imposed on the skin) are relatively limited, and the development and processing of tactile function are still thus little known. This question is particularly of high importance for infants with atypical early development such as those born prematurely who are exposed to many sensory (including tactile) stimulations (being in a hospital setting) during a critical period of brain development and those born at early term whose birth occurs at the precise time of cortical reorganization, in particular in the sensory areas. Some parents and health-care providers have for instance reported that children born prematurely exhibit atypical (e.g. higher) sensitivity to “benign” tactile stimuli. In the present study, we hypothesized that preterm and early-term infants may show altered tactile sensitivity. We compared the behavioral responses around term-equivalent age of infants born either pre-term, early-term or at term to the application of a light (0.008 grams) mechanical stimulus. We found that almost all preterm infants perceive this tactile stimulus, contrarily to the two other groups of infants. This extreme tactile sensitivity may be due to experiential, maturational or more likely both processes. We also compared the tactile sensitivity of these infants to that of adults. We found that adults were irresponsive to the light mechanical stimulus. This finding opens not only new insights in understanding development of tactile processing, but also new lines of thought about the particular sensory world of premature and early-term infants and hence about the potential impact of early care practices.