Movement outcomes of infants born moderate and late preterm

Influence of Preterm Birth and Low Birthweight on Physical Fitness: A Systematic Review, Meta-Analysis, and Meta-Regression

BACKGROUND

Preterm birth and low birthweight (LBW) might be associated with reduced physical fitness, although evidence remains inconclusive.

OBJECTIVE

To examine the influence of preterm birth and LBW on physical fitness, as well as to assess whether variables such as gestational age, birthweight, or age at assessment moderate these effects.

METHODS

PubMed, Scopus, and PsycINFO were systematically searched from inception to 7 December 2023 for case-control and cohort studies analyzing the association between preterm birth or LBW (or gestational age or birthweight as continuous variables) with at least one physical fitness-related outcome (i.e., cardiorespiratory fitness (CRF), muscle strength, flexibility, speed, agility). Random-effects meta-analysis and meta-regression models were used to estimate the pooled effect size, as well as to examine potential associations between the magnitude of the effect and gestational age, birthweight, or age at assessment.

RESULTS

Fifty-two studies (n = 920,603 participants, average age ranging from 4.7 to 34.4 years) were included. Preterm birth was associated with reduced CRF (standardized mean difference (SMD) = -0.38, 95% confidence interval (CI) = -0.51 to -0.25) and muscle strength (SMD = -0.44, 95% CI = -0.79 to -0.08). LBW was associated with reduced CRF (SMD = -0.40, 95% CI = -0.64 to -0.17), muscle strength (SMD = -0.18, 95% CI = -0.24 to -0.13), flexibility (SMD = -0.11, 95% CI = -0.22 to -0.01), and agility (SMD = -0.99, 95% CI = -1.91 to -0.07). Meta-regression analyses showed that a lower gestational age or birthweight were associated with larger reductions in physical fitness, whereas no consistent association was found for the age at assessment.

CONCLUSION

Both preterm birth and LBW seem associated with reduced physical fitness regardless of age, with larger reductions overall observed in individuals with lower gestational age or birthweight. These findings might support the implementation of preventive strategies (e.g., fitness monitoring and physical exercise interventions) in these populations through the life course. PROSPERO registration: CRD42021231845.

Longitudinal pilot study of oxygen saturation indices in healthy preterm infants

BACKGROUND

This study aimed to determine patterns of nocturnal pulse oximetry indices in moderate to late preterm infants, and investigate the relationship between oxygen desaturations, the apnoea hypopnoea index, and both corrected gestational and postnatal age.

METHODS

21 healthy infants born at 32 + 0 - 36 + 6 weeks gestation underwent serial nocturnal pulse oximetry studies and respiratory polygraphy studies until 40 weeks corrected gestational age (CGA). The main outcome measures were number of >3% oxygen desaturations/hour (ODI3), mean oxygen saturations, and number of apnoeas and hypopnoeas/hour.

RESULTS

Median ODI3 increased between weeks 1 and 3 from 49.9 to 85.4/hour (p = 0.017). Mean oxygen saturations reached a corresponding nadir of 96.0% in week 3, then increased to 96.8% in week 6 (p = 0.019). Mixed effects modelling demonstrated that ODI3 and mean saturations were influenced by postnatal age but not CGA (p < 0.05). Desaturations frequently occurred without an apnoea or hypopnoea.

CONCLUSION

ODI3 rises then falls during the first 8 weeks of life in moderate to late preterm infants, independently of CGA. These interesting preliminary results highlight the importance of further serial data collection to generate age-specific normal ranges, and develop a better understanding of respiratory control in preterm infants.

IMPACT

The frequency of >3% oxygen desaturations (ODI3) in healthy moderate to late preterm infants rises then falls after birth, peaking in postnatal week 3. There is a corresponding nadir in mean saturations. There were significant non-linear relationships between ODI3/mean saturations and postnatal age, but not corrected gestational age. The majority of brief oxygen desaturations occurred without an apnoea or hypopnoea. Normal ranges for oxygen saturation indices are not known in this population. These results demonstrate the need for further serial data collection to generate age-specific normal ranges and inform oxygen prescribing guidelines.

Caffeine to prevent intermittent hypoxaemia in late preterm infants: randomised controlled dosage trial

OBJECTIVE

To establish the most effective and best tolerated dose of caffeine citrate for the prevention of intermittent hypoxaemia (IH) in late preterm infants.

DESIGN

Phase IIB, double-blind, five-arm, parallel, randomised controlled trial.

SETTING

Neonatal units and postnatal wards of two tertiary maternity hospitals in New Zealand.

PARTICIPANTS

Late preterm infants born at 34+0-36+6 weeks' gestation, recruited within 72 hours of birth.

INTERVENTION

Infants were randomly assigned to receive a loading dose (10, 20, 30 or 40 mg/kg) followed by 5, 10, 15 or 20 mg/kg/day equivolume enteral caffeine citrate or placebo daily until term corrected age.

PRIMARY OUTCOME

IH (events/hour with oxygen saturation concentration ≥10% below baseline for ≤2 min), 2 weeks postrandomisation.

RESULTS

132 infants with mean (SD) birth weight 2561 (481) g and gestational age 35.7 (0.8) weeks were randomised (24-28 per group). Caffeine reduced the rate of IH at 2 weeks postrandomisation (geometric mean (GM): 4.6, 4.6, 2.0, 3.8 and 1.7 events/hour for placebo, 5, 10, 15 and 20 mg/kg/day, respectively), with differences statistically significant for 10 mg/kg/day (GM ratio (95% CI] 0.39 (0.20 to 0.76]; p=0.006) and 20 mg/kg/day (GM ratio (95% CI] 0.33 (0.17 to 0.68]; p=0.003) compared with placebo. The 20 mg/kg/day dose increased mean (SD) pulse oximetry oxygen saturation (SpO2) (97.2 (1.0) vs placebo 96.0 (0.8); p<0.001), and reduced median (IQR) percentage of time SpO2 <90% (0.5 (0.2-0.8) vs 1.1 (0.6-2.4); p<0.001) at 2 weeks, without significant adverse effects on growth velocity or sleeping.

CONCLUSION

Caffeine reduces IH in late preterm infants at 2 weeks of age, with 20 mg/kg/day being the most effective dose.

TRIAL REGISTRATION NUMBER

ACTRN12618001745235.

Early structural connectivity within the sensorimotor network: Deviations related to prematurity and association to neurodevelopmental outcome

Consisting of distributed and interconnected structures that interact through cortico-cortical connections and cortico-subcortical loops, the sensorimotor (SM) network undergoes rapid maturation during the perinatal period and is thus particularly vulnerable to preterm birth. However, the impact of prematurity on the development and integrity of the emerging SM connections and their relationship to later motor and global impairments are still poorly understood. In this study we aimed to explore to which extent the early microstructural maturation of SM white matter (WM) connections at term-equivalent age (TEA) is modulated by prematurity and related with neurodevelopmental outcome at 18 months corrected age. We analyzed 118 diffusion MRI datasets from the developing Human Connectome Project (dHCP) database: 59 preterm (PT) low-risk infants scanned near TEA and a control group of full-term (FT) neonates paired for age at MRI and sex. We delineated WM connections between the primary SM cortices (S1, M1 and paracentral region) and subcortical structures using probabilistic tractography, and evaluated their microstructure with diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) models. To go beyond tract-specific univariate analyses, we computed a maturational distance related to prematurity based on the multi-parametric Mahalanobis distance of each PT infant relative to the FT group. Our results confirmed the presence of microstructural differences in SM tracts between PT and FT infants, with effects increasing with lower gestational age at birth. Maturational distance analyses highlighted that prematurity has a differential effect on SM tracts with higher distances and thus impact on (i) cortico-cortical than cortico-subcortical connections; (ii) projections involving S1 than M1 and paracentral region; and (iii) the most rostral cortico-subcortical tracts, involving the lenticular nucleus. These different alterations at TEA suggested that vulnerability follows a specific pattern coherent with the established WM caudo-rostral progression of maturation. Finally, we highlighted some relationships between NODDI-derived maturational distances of specific tracts and fine motor and cognitive outcomes at 18 months. As a whole, our results expand understanding of the significant impact of premature birth and early alterations on the emerging SM network even in low-risk infants, with possible relationship with neurodevelopmental outcomes. This encourages further exploration of these potential neuroimaging markers for prediction of neurodevelopmental disorders, with special interest for subtle neuromotor impairments frequently observed in preterm-born children.

Moderately and Late Preterm Infants: Short- and Long-Term Outcomes From a Registry-Based Cohort

Background: While most studies on the association of preterm birth and cerebral palsy (CP) have focused on very preterm infants, lately, attention has been paid to moderately preterm [32 to <34 weeks gestational age (GA)] and late preterm infants (34 to <37 weeks GA).

Methods: In order to report on the outcomes of a cohort of moderately and late preterm infants, derived from a population-based CP Registry, a comparative analysis of data on 95 moderately preterm infants and 96 late preterm infants out of 1,016 with CP, was performed.

Results: Moderately preterm neonates with CP were more likely to have a history of N-ICU admission (p = 0.001) and require respiratory support (p < 0.001) than late preterm neonates. Birth weight was significantly related to early neonatal outcome with children with lower birth weight being more likely to have a history of N-ICU admission [moderately preterm infants (p = 0.006)/late preterm infants (p < 0.001)], to require ventilator support [moderately preterm infants (p = 0.025)/late preterm infants (p = 0.014)] and not to have neonatal seizures [moderately preterm infants (p = 0.044)/late preterm infants (p = 0.263)]. In both subgroups, the majority of children had bilateral spastic CP with moderately preterm infants being more likely to have bilateral spastic CP and less likely to have ataxic CP as compared to late preterm infants (p = 0.006). The prevailing imaging findings were white matter lesions in both subgroups, with statistically significant difference between moderately preterm infants who required ventilator support and mainly presented with this type of lesion vs. those who did not and presented with gray matter lesions, maldevelopments or miscellaneous findings. Gross motor function was also assessed in both subgroups without significant difference. Among late preterm infants, those who needed N-ICU admission and ventilator support as neonates achieved worse fine motor outcomes than those who did not.

Conclusions: Low birth weight is associated with early neonatal problems in both moderately and late preterm infants with CP. The majority of children had bilateral spastic CP and white matter lesions in neuroimaging. GMFCS levels were comparable in both subgroups while BFMF was worse in late preterm infants with a history of N-ICU admission and ventilator support.

(Rad 8)Caffeine prophylaxis to improve intermittent hypoxaemia in infants born late preterm: a randomised controlled dosage trial (Latte Dosage Trial)

INTRODUCTION

Infants born late preterm (34+0 to 36+6 weeks' gestational age) have frequent episodes of intermittent hypoxaemia compared with term infants. Caffeine citrate reduces apnoea and intermittent hypoxaemia and improves long-term neurodevelopmental outcomes in infants born very preterm and may have similar effects in late preterm infants. Clearance of caffeine citrate increases with gestational age and late preterm infants are likely to need a higher dose than very preterm infants. Our aim is to determine the most effective and best-tolerated dose of caffeine citrate to reduce transient intermittent hypoxaemia events in late preterm infants.

METHODS AND ANALYSIS

A phase IIB, double-blind, five-arm, parallel, randomised controlled trial to compare the effect of four doses of oral caffeine citrate versus placebo on the frequency of intermittent hypoxaemia. Late preterm infants will be enrolled within 72 hours of birth and randomised to receive 5, 10, 15 or 20 mg/kg/day caffeine citrate or matching placebo daily until term corrected age. The frequency of intermittent hypoxaemia (events/hour where oxygen saturation concentration is ≥10% below baseline for ≤2 min) will be assessed with overnight oximetry at baseline, 2 weeks after randomisation (primary outcome) and at term corrected age. Growth will be measured at these timepoints, and effects on feeding and sleeping will be assessed by parental report. Data will be analysed using generalised linear mixed models.

ETHICS AND DISSEMINATION

This trial has been approved by the Health and Disability Ethics Committees of New Zealand (reference 18/NTA/129) and the local institutional research review committees. Findings will be disseminated to peer-reviewed journals to clinicians and researchers at local and international conferences and to the public. The findings of the trial will inform the design of a large multicentre trial of prophylactic caffeine in late preterm infants, by indicating the most appropriate dose to use and providing information on feasibility.

TRIAL REGISTRATION NUMBER

ACTRN12618001745235; Pre-results.

Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.

Intermittent Hypoxemia in Infants Born Late Preterm: A Prospective Cohort Observational Study

OBJECTIVE

To determine if late preterm infants are at increased risk of intermittent hypoxemic events compared with term infants.

STUDY DESIGN

Prospective, cohort, observational study of late preterm infants (34^0/7-36^6/7 weeks gestational age) and term infants (39^0/7-41^6/7 weeks gestational age). Overnight pulse oximetry recordings were performed on days 2-3 after birth, at term equivalent age, and at 45 weeks postmenstrual age. The primary outcome was the frequency of intermittent hypoxemic events per hour (desaturation ≥10% below the preceding baseline SpO₂) on the oximetry recording on days 2-3 after birth. Data were analyzed by the Student t test and general linear mixed model.

RESULTS

Eighty-five infants were enrolled (late preterm n = 43; term infants n = 42). On days 2-3 after birth, late preterm infants had more intermittent hypoxemic events than term infants (events per hour, mean ± standard error of the mean, 2.5 ± 1.2 vs 1.0 ± 1.2; P < .0001). On mixed model analysis, late preterm infants had a higher frequency of intermittent hypoxemic events at term equivalent age, which decreased to a similar frequency as in term infants by 45 weeks postmenstrual age (events per hour; term equivalent age, late preterm: least squares mean, 3.7 [95% CI, 2.7-5.1] vs term: least squares mean, 1.7 [95% CI, 1.2-2.3]; 45 weeks postmenstrual age, late preterm: least squares mean, 1.5 [95% CI, 1.1-2.1] vs term: least squares mean, 1.9 [95% CI, 1.4-2.6]; P < .0005).

CONCLUSIONS

Late preterm infants are at greater risk of intermittent hypoxemia than term infants soon after birth. We speculate that preventing intermittent hypoxemia in late preterm infants may improve neurodevelopmental outcomes.

Risk of developmental delay: Comparison of late preterm and full term Canadian infants at age 12 months

BACKGROUND

Late preterm (34(0/7) to 36(6/7)weeks gestation) infants may experience developmental delays greater than those found in term (≥ 37(0/7)weeks gestation) infants.

AIM

The aim of this study was to compare the risk of developmental delay between late preterm and full-term Canadian born infants at age 12months, and to determine infant and maternal factors associated with risk of delay.

METHODS

A descriptive comparative study was conducted from data available from the All Our Babies community-based, prospective, pregnancy cohort in Calgary, Alberta. Participants were a sample of mothers of 52 infants born late preterm and 156 randomly selected mothers of term infants, matched for infant sex; eligible infants were singleton births. Mothers completed a developmental screening tool, the Ages and Stages Questionnaire, version 3 (ASQ-3), when their infant was age 12months. Corrected age (CA) was used for preterm infants.

RESULTS

Both late preterm and term infants who required neonatal intensive care (NICU) were more likely to demonstrate risk of developmental delay. Compared to term infants, there was a trend for late preterm infants to be at risk of communication and gross motor delay at age 12months CA that was attenuated to the null when adjustments were made for NICU admission and other covariates.

CONCLUSIONS

Infants born between 34 and 41weeks who are admitted to NICU are at increased risk of developmental delay. Early identification of risk provides an opportunity for referral for developmental assessment and early intervention programming.

Brain Volumes at Term-Equivalent Age Are Associated with 2-Year Neurodevelopment in Moderate and Late Preterm Children

OBJECTIVE

To explore the association between brain maturation, injury, and volumes at term-equivalent age with 2-year development in moderate and late preterm children.

STUDY DESIGN

Moderate and late preterm infants were recruited at birth and assessed at age 2 years using the Bayley Scales of Infant and Toddler Development, Third Edition. Brain magnetic resonance imaging (MRI) was performed at term-equivalent age and qualitatively assessed for brain maturation (myelination of the posterior limb of the internal capsule and gyral folding) and injury. Brain volumes were measured using advanced segmentation techniques. The associations between brain MRI measures with developmental outcomes were explored using linear regression analyses.

RESULTS

A total of 197 children underwent MRI and assessed using the Bayley Scales of Infant and Toddler Development, Third Edition. Larger total brain tissue volumes were associated with higher cognitive and language scores (adjusted coefficients per 10% increase in brain size; 95% CI of 3.2 [0.4, 5.6] and 5.6 [2.4, 8.8], respectively). Similar relationships were documented for white matter volumes with cognitive and language scores, multiple cerebral structures with language scores, and cerebellar volumes with motor scores. Larger cerebellar volumes were independently associated with better language and motor scores, after adjustment for other perinatal factors. There was little evidence of relationships between myelination of the posterior limb of the internal capsule, gyral folding, or injury with 2-year development.

CONCLUSIONS

Larger total brain tissue, white matter, and cerebellar volumes at term-equivalent age are associated with better neurodevelopment in moderate and late preterm children. Brain volumes may be an important marker for neurodevelopmental deficits described in moderate and late preterm children.

Delayed growth, motor function and learning in preterm pigs during early postnatal life

Preterm birth interrupts normal fetal growth with consequences for postnatal growth and organ development. In preterm infants, many physiological deficits adapt and disappear with advancing postnatal age, but some may persist into childhood. We hypothesized that preterm birth would induce impaired organ growth and function during the first postnatal week in pigs, while motor abilities and behavioral characteristics would show more persistent developmental delay. Cesarean-delivered preterm ( n = 112, 90% gestation) or term ( n = 56, 100% gestation) piglets were reared under identical conditions and euthanized for blood and organ collection on postnatal days 0, 5, or 26. Body weight gain remained lower in preterm vs. term pigs up to day 26 (25.5 ± 1.5 vs. 31.0 ± 0.5 g·kg−1·day−1, P < 0.01) when relative weights were higher for brain and kidneys and reduced for liver and spleen. Neonatal preterm pigs had reduced values for blood pH, Po2, glucose, lactate, hematocrit, and cortisol, but at day 26, most values were normalized, although plasma serotonin and IGF 1 levels remained reduced. Preterm pigs showed delayed neonatal arousal and impaired physical activity, coordination, exploration, and learning, relative to term pigs (all P < 0.05). Supplementation of parenteral nutrition during the first 5 days with an enteral milk diet did not affect later outcomes. In preterm pigs, many physiological characteristics of immaturity disappeared by 4 wk, while some neurodevelopmental deficits remained. The preterm pig is a relevant animal model to study early dietary and pharmacological interventions that support postnatal maturation and neurodevelopment in preterm infants.

Self-reported sleep in late pregnancy in relation to birth size and fetal distress: the E Moe, Māmā prospective cohort study

OBJECTIVES

To explore associations between features of sleep during pregnancy and adverse outcomes for the infant.

SETTING

E Moe, Māmā is a cohort study in Aotearoa/New Zealand that investigates self-reported sleep and maternal health in late pregnancy and the postpartum period.

PARTICIPANTS

Women (N=633; 194 Māori) reported detailed information on their sleep duration, quality, disturbances, disorders (snoring, breathing pauses, twitching legs, restless legs) and daytime sleepiness between 35 and 37 weeks gestation.

OUTCOME MEASURES

Birthweight and fetal distress during labour were extracted from medical records. Associations between each sleep variable and small or large for gestational age (SGA/LGA) using customised birthweight centile or fetal distress were estimated using multinomial/logistic regression, controlling for potential confounders. Secondary analyses considered differences in associations between Māori and non-Māori women.

RESULTS

There was some indication that breathing pauses (a measure of sleep apnoea) were associated with both SGA (OR 2.8, 95% CI 0.9 to 9.0, p=0.08) and LGA (OR 2.0, 95% CI 0.7 to 5.7, p=0.20), with the association for LGA being stronger when only pregnancy-onset breathing pauses were considered (OR 3.5, 95% CI 1.3 to 9.6, p=0.01). There was also some evidence that pregnancy-onset leg twitching (OR 3.3, 95% CI 1.1 to 10.0, p=0.03) and frequent sleep disturbance due to feeling too hot or too cold (OR 1.7, 95% CI 0.9 to 3.6, p=0.13) were associated with higher risk of fetal distress. Other sleep measures, including snoring, were not associated with SGA, LGA or fetal distress. Many of the associations we observed were considerably stronger in Māori compared with non-Māori women.

CONCLUSIONS

We did not find evidence of previously reported associations between snoring and SGA. Our findings tentatively suggest that self-reported breathing pauses and leg twitching in late pregnancy are associated with infant outcomes, and highlight ethnic inequalities.

Macro preemies: no thresholds for risks or concerns

PURPOSE OF REVIEW

To provide an overview of the literature regarding medical and developmental risks for moderate to late preterm infants (32-36 weeks gestation), with particular attention to the pediatrician's role in care during both inpatient and outpatient periods.

RECENT FINDINGS

Although the risks of medical issues and developmental delays decrease with increasing gestational age, research suggests that infants born after 32 weeks' gestation often exhibit significant morbidities associated with prematurity. These infants, often referred to as 'macro preemies', have been found to be at a greater risk for medical complications secondary to immature organ systems including impairments in temperature regulation, respiratory functioning, feeding coordination, bilirubin excretion, glucose control, and infection susceptibility. Recent studies of macro preemies also suggest a higher incidence of significant deficits noted in gross and fine motor skills, speech and communication, and learning and behavior compared to their full-term counterparts. Without careful attention from birth, macro preemie infants could be susceptible to both medical issues and developmental delays.

SUMMARY

Physicians should be aware of the research regarding increased medical and developmental risks for all infants born before term in order to provide their patients with comprehensive medical and neurodevelopmental follow-up care.

Movement recognition technology as a method of assessing spontaneous general movements in high risk infants

Preterm birth is associated with increased risks of neurological and motor impairments such as cerebral palsy. The risks are highest in those born at the lowest gestations. Early identification of those most at risk is challenging meaning that a critical window of opportunity to improve outcomes through therapy-based interventions may be missed. Clinically, the assessment of spontaneous general movements is an important tool, which can be used for the prediction of movement impairments in high risk infants. Movement recognition aims to capture and analyze relevant limb movements through computerized approaches focusing on continuous, objective, and quantitative assessment. Different methods of recording and analyzing infant movements have recently been explored in high risk infants. These range from camera-based solutions to body-worn miniaturized movement sensors used to record continuous time-series data that represent the dynamics of limb movements. Various machine learning methods have been developed and applied to the analysis of the recorded movement data. This analysis has focused on the detection and classification of atypical spontaneous general movements. This article aims to identify recent translational studies using movement recognition technology as a method of assessing movement in high risk infants. The application of this technology within pediatric practice represents a growing area of inter-disciplinary collaboration, which may lead to a greater understanding of the development of the nervous system in infants at high risk of motor impairment.

Differences between late preterm and full-term infants: comparing effects of a short bout of practice on early reaching behavior

This study compared the effects of a short bout of practice on reaching behavior between late preterm and full-term infants at the onset of goal-directed reaching. Twelve late preterm infants and twelve full-term infants received reaching practice based on a serial schedule. Late preterm and full-term infants were assessed in 3.3±1.4 and 2.6±1.0 days after the onset of goal-directed reaching in two measures in a single day: immediately before practice (pre-test) and immediately after practice (post-test). During the assessments, the infants were placed in a baby chair and a rubber toy was presented at their midline within reaching distance for 2 min. Between assessments, the infants received practice of toy-oriented reaching in 3 activities repeated for approximately 4 min. The activities were elicited in a pre-established serial sequence and were applied by a physical therapist. During the pre-test, late preterm infants presented lower range of proximal adjustments, greater proportion of reaches with semi-open hand, and greater proportion of reaches without grasping than the full-term infants. During the post-test, late preterm infants presented greater motor variability of proximal adjustments, but explored and selected distal control and grasping outcomes less compared to the full-term group. Differences in reaching and gross motor behavior between late preterm and full-term infants can be found at the age of reaching onset. Practice provided new opportunities for late preterm infants to improve perception-action coupling to reach; however, relative to full-terms, they seemed less advanced in benefiting from the experience for more refined manual tasks.