Gross motor development in full-term Greek infants assessed by the Alberta Infant Motor Scale: Reference values and socioeconomic impact

Objective

The aims of this study were to investigate gross motor development in Greek infants and establish AIMS percentile curves and to examine possible association of AIMS scores with socioeconomic parameters.

Methods

Mean AIMS scores of 1068 healthy Greek full-term infants were compared at monthly age level with the respective mean scores of the Canadian normative sample. In a subgroup of 345 study participants, parents provided, via interview, information about family socioeconomic status. Multiple linear regression analysis was performed to evaluate the relationship of infant motor development with socioeconomic parameters.

Results

Mean AIMS scores did not differ significantly between Greek and Canadian infants in any of the 19 monthly levels of age. In multiple linear regression analysis, the educational level of the mother and also whether the infant was being raised by grandparents/babysitter were significantly associated with gross motor development (p = 0.02 and p < 0.001, respectively), whereas there was no significant correlation of mean AIMS scores with gender, birth order, maternal age, paternal educational level and family monthly income.

Conclusions

Gross motor development of healthy Greek full-term infants, assessed by AIMS during the first 19 months of age, follows a similar course to that of the original Canadian sample. Specific socioeconomic factors are associated with the infants' motor development.     

Maternal interactive behaviour as a predictor of preschoolers' attachment representations among full term and premature samples

Background

Associations between maternal sensitivity and child attachment have been established in many samples, but the strength of the association varies across populations. The sensitivity–attachment link has never been examined at the level of representations nor among premature samples.

Objective

The present study is aimed at exploring associations between maternal interactive behaviour and children's attachment representations in a population of preterm and full-term infants.

Method

Maternal interactive behaviour was assessed at 6 and 18 months (Ainsworth Sensitivity Scale & Care Index) and children's attachment representations were measured at 42 months (Attachment Story Completion Task) in a sample of preterm (N = 48) and full-term (N = 23) infants.

Results

Maternal unresponsiveness at 6 months and sensitivity at 18 months explained 54% of the variance of disorganized attachment representations in the full-term group but was not significantly related to attachment patterns in the preterm group.

Conclusion

These results corroborate previous work on the causes of disorganized attachment and also point to the need to consider the development of attachment differently for children evolving in specific developmental contexts. They especially stress the importance of distinguishing between risk factors associated with the mother as opposed to the child.     

Placental pathology and neurological morbidity in preterm infants during the first two weeks after birth

Background

The placenta plays a crucial role during pregnancy and dysfunction causes long-term neurological problems. Identifying placenta-related risks for neurological problems shortly after birth may provide clues for early interventions aiming to improve neurological outcome.

Objective

To determine the association between placental pathology and neurological morbidity in preterm infants during the first two weeks after birth.

Study design

Placentas of 52 singleton, preterm infants (GA: 25–31 weeks, BW: 560–2250 grammes) were examined for histopathology. The infants' neurological condition shortly after birth was determined by assessing the quality of their general movements (GMs): normal, abnormal, or hypokinetic, on days 5, 8, and 15. A motor optimality score (MOS) was also assigned.

Results

Examination of the placentas revealed maternal vascular underperfusion (n = 29), ascending intrauterine infection (AIUI) (n = 19), villitis of unknown aetiology (n = 6), chronic deciduitis (n = 11), foetal thrombotic vasculopathy (FTV) (n = 9), and elevated nucleated red blood cells (NRBCs) as a marker for foetal hypoxia (n = 7). None of the placental lesions were significantly associated with the quality of GMs or MOS.

Conclusions

This study indicated that placental lesions were not associated with infants' neurological condition as measured by the quality of their general movements during the first two weeks after birth.     

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.     

The Stockholm Neonatal Family-Centered Care Study: effects on salivary cortisol in infants and their mothers

Background

Parental involvement in the care of preterm infants in neonatal intensive care units (NICUs) is common, but little is known about the effect on stress responses in mothers and infants.

Aims

The aim of this study is to evaluate the effect of family-centered care on salivary cortisol reactivity in mothers and preterm infants and the correlation between the mothers' and the preterm infants' salivary cortisol levels.

Methods

This study is part of a randomized controlled trial conducted at two level-II NICUs, including Family Care (FC), where parents were able to stay 24 h/day from admission to discharge, and Standard Care (SC). To investigate the cortisol response, saliva was collected from 289 preterm infants and their mothers before and after a diaper change at the time of discharge.

Results

No significant differences were found between the two groups in salivary cortisol reactivity, either in mothers or in infants. The results revealed a correlation between preterm infants' and their mothers' baseline and response cortisol in the FC group: r = 0.31 (p = 0.001) and r = 0.24 (p = 0.01), respectively. Such correlation was not observed in the SC group: r = 0.14 (p = 0.14) and r = 0.18 (p = 0.07), respectively.

Conclusions

Family-centered care had no effect on salivary cortisol reactivity during diaper change. However, sharing the same environment may increase the concordance between preterm infants' and their mothers' salivary cortisol levels.     

Preterm infant weight gain is increased by massage therapy and exercise via different underlying mechanisms

Objective

To compare the effects of massage therapy (moderate pressure stroking) and exercise (flexion and extension of limbs) on preterm infants' weight gain and to explore potential underlying mechanisms for those effects.

Methods

Weight gain and parasympathetic nervous system activity were assessed in 30 preterm infants randomly assigned to a massage therapy group or to an exercise group. Infants received 10 min of moderate pressure massage or passive flexion and extension of the limbs 3 times per day for 5 days, and EKGs were collected during the first session to assess vagal activity.

Results

Both massage and exercise led to increased weight gain. However, while exercise was associated with increased calorie consumption, massage was related to increased vagal activity.

Conclusion

Taken together, these findings suggest that massage and exercise lead to increased preterm infant weight gain via different underlying mechanisms.     

Assessment of motor behaviour in high-risk-infants at 3 months predicts motor and cognitive outcomes in 10 years old children

Background

The general movement assessment has mainly been used to identify children with cerebral palsy (CP). A detailed assessment of quality of infant motor repertoire using parts of the “Assessment of Motor Repertoire — 3 to 5 Months” which is based on Prechtl's general movement assessment can possibly identify later motor and cognitive problems in children without CP.

Aims

This study aims to determine whether analysis of quality of infant motor repertoire has predictive value for motor and cognitive outcomes at age 10 in children at risk for later neurological impairment.

Study design

A longitudinal study design was used.

Subjects

Video-recordings of 40 “neurologically high-risk” infants at 14 weeks post-term age were analysed with respect to motor repertoire.

Outcome measures

Fidgety movements were classified as present or absent. Quality of concurrent motor repertoire was classified as normal if smooth and fluent and abnormal if jerky, monotonous or stiff. Poor motor outcome was defined as a score ≤ 5th centile on the Movement-Assessment-Battery-2, while poor cognitive outcome as total IQ < 85 on Wechsler Intelligence Scale-III.

Results

Among the high-risk children with presence of fidgety movements, poor motor and/or cognitive outcome at 10 years was identified by abnormal concurrent motor repertoire at 14 weeks post-term age in 86% (95% CI: 0.60–0.96) of the children. On the other hand, 71% (95% CI: 0.47–0.87) of those with normal motor and cognitive outcomes were identified by presence of fidgety movements and normal motor repertoire.

Conclusions

Assessment of quality of infant motor repertoire may be a valuable early clinical marker for later impaired motor and cognitive outcomes in high-risk children who do not develop CP.     

Acute cardiovascular responses in preterm infants at 34–39 weeks of gestational age

Background

Premature infants demonstrate immature physiological control mechanisms; however their acute cardiovascular control has not yet been widely studied.

Aim

The aim of this study was to analyze heart rate (HR) and blood pressure (BP) control in preterm infants.

Subjects

Twenty preterm infants with a mean gestational age of 31 ± 2.4 (26–34) weeks at birth were evaluated at a gestational age of 36 ± 1.5 (34–39) weeks. Results were compared to twenty, healthy, full-term, control infants studied at the age of 12 ± 3 weeks.

Outcome measures

HR and BP responses to 45° head-up tilt and side motion tests during non-rapid eye movement sleep were analyzed. In addition, HR responses to spontaneous arousals from non-rapid eye movement sleep were evaluated.

Results

Preterm infants showed significantly smaller initial HR and BP responses compared with controls in head-up tilt (HR p = 0.0005, systolic BP p = 0.02, diastolic BP p = 0.01) and side motion tests (HR p = 0.002, systolic BP p < 0.0001, diastolic BP p < 0.0001). Furthermore, in tilt tests, preterm infants presented with greater intersubject variability in BP responses than controls (systolic BP p = 0.009, diastolic BP p = 0005). Preterm HR responses to spontaneous arousals were similar to controls.

Conclusions

This study indicates immature vestibulo-mediated cardiovascular control in preterm infants compared with term infants. This is seen as attenuated BP responses to side motion test and more labile acute BP control to postural challenge.     

Motor trajectories from 4 to 18 months corrected age in infants born at less than 30 weeks of gestation

Background

Preterm infants are recognised as developing at a significantly slower rate than their full-term peers and with different movement quality.

Aim

This study aimed to describe the longitudinal gross motor trajectories of these infants in the first 18 months of (corrected) age and investigate factors associated with gross motor development.

Study design

A longitudinal study was conducted with convenience samples of 58 preterm infants born ≤ 29 weeks of gestation and 52 control full-term infants in Australia.

Outcome measures

The infants were assessed at 4, 8, 12 and 18 months of (corrected) age using the Alberta Infant Motor Scale (AIMS).

Results

Forty-six preterm and 48 control infants completed all four assessments. The preterm group scored significantly lower on various sub-scores at all age levels. Almost half of the preterm infants demonstrated less progression in the sit sub-scale from 4 to 8 months (corrected) age, possibly due to an imbalance between flexor and extensor strength in the trunk. At 12 and 18 months of (corrected) age, lack of rotation and fluency in their movements were evident in some preterm infants. Presence of intra-ventricular haemorrhage and chronic lung disease were associated with poor motor performance at 4 months and use of postnatal steroids was associated with poor motor performance at 4, 8 and 18 months of corrected age.

Conclusion

The imbalance between flexor and extensor muscle strength in preterm infants had a stronger impact on motor development than usually expected. The AIMS appears to be a sensitive assessment tool to demonstrate the unique movement characteristics in this preterm cohort.     

Neonatal neurological examination of late preterm babies

Backgrounds

Healthy late-preterm (LP) infants examined at term equivalent age showed wider median and range of neurological scores than full-term infants; differences between infants born at 34 and those born at 35–36 weeks were also observed.

Aims

The aim of this study is to establish the range and frequency distribution of neonatal neurological scores in a cohort of low risk LP infants assessed during the first 3 days from birth.

Study design and subjects

118 low-risk infants born between 34 and 36 weeks of gestational age (GA) were assessed between 48 and 72 h from birth.

Outcome measures

The full version of the Hammersmith Neonatal Neurologic Assessment and the screening proforma were used to assess all the infants. The raw scores obtained were compared to those of full-term infants using the same examination.

Results

The distribution of neurological scores was similar among the 3 GAs for 26 items, with different median scores among LP infants born at 36 weeks and those born at 34 and 35 in only 2 items.LP infants showed a wider range of findings for each item than that of full term infants assessed soon after birth. Using the screening proforma, in our cohort, for each item the findings falling outside the 90% level were identical to those found in term-born and very preterm infants assessed at term age.

Conclusions

The neurological scores obtained in our cohort could help as reference data when examining LP infants at birth compared to age matched low risk infants.     

Bone status and associated factors measured by quantitative ultrasound in preterm and full-term newborn infants

Background

A clear understanding of the factors associated with bone status in newborn infants is essential for devising strategies for preventing osteoporotic fracture in future generations.

Objective

The aims of this study were to perform bone speed of sound (SOS) to assess the status of the tibia in preterm and full-term newborns, and to evaluate factors associated with bone status at birth.

Study designs

Bone SOS was measured by quantitative ultrasonography on the left tibia in full-term and preterm newborn infants immediately after birth. A birth chart and maternal history were recorded. Univariate and multivariate analyses were performed to identify factors affecting bone SOS at birth.

Subjects

The study analyzed 667 infants, including 370 males and 297 females, during study period.

Results

Univariate analysis revealed that gender, gestational age (GA) and birth anthropometrics significantly affected tibial bone SOS at birth whereas maternal factors did not. Multivariate multiple regression analysis revealed that gender (male-to-female coefficient of 45.71 and 32.52 in premature and full-term infants, respectively), GA (coefficient of 32.55 and 31.27 in premature and full-term infants, respectively, for every 1-week increase), and birth weight (coefficient of − 0.11 and − 0.103 in premature and full-term infants, respectively, for every 1-gram increase) were important factors affecting tibial bone SOS in both preterm and full-term newborn infants at birth.

Conclusions

Male gender and advanced GA have a positive effect on increasing tibial bone SOS at birth, while birth weight had a negative effect on increasing tibial bone SOS. Tibial bone SOS is higher in small-for-gestational-age infants than in those of appropriate-for-gestational-age infants.     

Change in cognitive abilities over time during preschool age in low risk preterm children

Background

More information is needed on ‘low-risk’ preterm infants' neurological outcome so that they can be included in follow-up programs at least until school age.

Objective

To examine the neuropsychological outcome in a group of low-risk low birth weight (LBW) children without neurological impairment followed from birth to 5 years of age.

Patients

26 intellectually normal children born preterm (30–34 weeks gestation) without major neurological disabilities and 23 control children born at term and matched for age, sex, and parental educational and occupational status.

Methods

Subjects already evaluated at 3 years of age underwent assessment again at 5 years using as neuropsychological outcome measures a wide range of tests including perceptual and visual–motor function, language comprehension and expression, and attention skills.

Results

When tested at 5 years, children born preterm still obtained significantly lower mean scores than controls on visual motor integration test (57 vs 64, p = 0.01), visual perception test (41 vs 43, p = 0.002) and a trend toward a lower score in the picture vocabulary test (81 vs 85.5, p = 0.07). The group of premature infants and controls improved their performance over time in the neuropsychological abilities investigated and, in some skills such as visual perception. Children born preterm took longer than those born at term to reach similar performance levels, 5 versus 3 years.

Conclusion

Ex low-risk children born preterm achieve lower scores over time in visual–motor and perceptual ability scales and in some language tests than children born at term. Like high-risk premature infants even those at low risk deserve regular follow-up with long-term programs.     

Cerebral palsy in children: Movements and postures during early infancy, dependent on preterm vs. full term birth

Background

A deviant motor behaviour at age 3 to 5 months is predictive of cerebral palsy (CP). Particular features of the early motor repertoire even proved predictive of the degree of functional limitations as classified on the Gross Motor Function Classification System (GMFCS) in children with CP, born preterm.

Aims

We aimed to determine whether an association between the early motor repertoire and the GMFCS also holds true for children born at term.

Study design

Longitudinal study.

Subjects

79 infants (60 boys and 19 girls; 47 infants born at term; video recorded for the assessment of movements and posture at age 9 to 20 weeks postterm age) who developed CP.

Outcome measures

The GMFCS was applied at age 2 to 5 years.

Results

Motor optimality at age 3 to 5 months showed a significant correlation with functional mobility and activity limitation as classified on the GMFCS at age 2 to 5 years in both children born at term (Spearman rho = − 0.66, p < 0.001) and born preterm (rho = − 0.37, p < 0.05). Infants born preterm were more likely to show normal movement patterns than infants born at term. A normal posture and an abnormal, jerky (yet not monotonous) movement character resulted in better levels of function and mobility. With the exception of one, none of the infants showed fidgety movements. A cramped-synchronised movement character, repetitive opening and closing of the mouth, and abnormal finger postures characterised children who would show a poor self-mobility later.

Conclusions

Assessing the quality of motor performance at 9 to 20 weeks postterm age (irrespective of the gestational age) improves our ability to predict later functional limitations in children with CP.     

Twin birth: An additional risk factor for poorer quality maternal interactions with very preterm infants?

Background

Twin birth can be considered an additional risk factor for poor interactions between mothers and their very preterm (VP; < 32 weeks' gestation) infants.

Aims

To explore if mothers of (VP) twins experience higher levels of stress than mothers of singletons and if mother–twin infant dyads experience poorer quality interactions.

Method

Mothers of VP twin infants (N = 17) were closely matched to mothers of VP singleton infants (N = 17). Mother–infant interaction was assessed before discharge from hospital and during a home visit at three months corrected age using the Nursing Child Assessment Teaching Scale (NCATS). Mothers' responsiveness to their infants was assessed using the Responsivity subscale of the Home Observation for Measurement of the Environment (HOME) and mothers completed the Parenting Stress Index short form (PSI-SF).

Results

Mothers of twins had significantly lower HOME responsiveness scores (median 9 vs. 10) at three months corrected age and were more likely to have total PSI-SF scores in the clinical range (> 90th percentile) compared to mothers of singletons (Fishers exact probability = 0.05). Twin infants had lower mean Total Child Domain NCATS scores than singletons both at discharge (9.07 vs. 11.33) and at three months corrected age (13.18 vs. 15.71) indicating they were less responsive communicators.

Conclusions

VP twins present a greater challenge than singletons as their mothers experience high levels of parenting stress. Although mothers appear to compensate for twin infants' poorer clarity of cues in a structured, one to one task, mothers of twins were less responsive than mothers of singletons in an unstructured setting.     

Placental pathology is associated with illness severity in preterm infants in the first twenty-four hours after birth

Background

Placental pathology is associated with long-term neurological morbidity. Little is known about the association of placental pathology and illness severity directly after birth in preterm infants.

Objective

To determine the association between placental pathology and illness severity in preterm infants during the first 24 h after birth.

Study design

Placentas of 40 preterm infants, born after singleton pregnancies (gestational age 25.4-31.7 weeks, birth weight 560-2250 g) were assessed for histopathology. Illness severity was measured using the Score of Neonatal Acute Physiology Perinatal Extension (SNAPPE). A high SNAPPE reflects high illness severity.

Results

Examination of the 40 placentas revealed: pathology consistent with maternal vascular underperfusion (MVU) (n = 24), ascending intrauterine infection (AIUI) (n = 17), villitis of unknown aetiology (VUE) (n = 6), foetal thrombotic vasculopathy (FTV) (n = 6), elevated nucleated red blood cells (NRBCs) (n = 6), and chronic deciduitis (n = 10). SNAPPE ranged from 1 to 53 (median 10). Infants with elevated NRBCs had a higher SNAPPE than infants without elevated NRBCs (median 30 vs. 10, p = 0.014). The same was found for the presence of FTV (median 30 vs. 10, p = 0.019). No relation existed between SNAPPE and the other placental pathologies.

Conclusions

Elevated NRBCs and FTV were associated with higher illness severity during the first 24 h after birth in preterm infants. Ascending intrauterine infection was not associated with high illness severity.     

A comparison of executive function in very preterm and term infants at 8 months corrected age

Background

Executive function (EF) emerges in infancy and continues to develop throughout childhood. Executive dysfunction is believed to contribute to learning and attention problems in children at school age. Children born very preterm are more prone to these problems than their full-term peers.

Aim

To compare EF in very preterm and full-term infants at 8 months after expected date of delivery.

Subjects

37 very preterm infants without identified disabilities, and 74 gender and age matched healthy full-term infants. The very preterm infants were all ≤ 32 weeks gestation and < 1250 g birthweight.

Outcome measures

EF tasks which measured working memory, inhibition of distraction, and planning at 8 months after expected date of delivery.

Results

The very preterm infants performed significantly more poorly than the full-term infants on all measures of executive function. No significant differences were found between very preterm and full-term infants on any of potentially confounding variables of, infant temperament, maternal education, family income and maternal psychological wellbeing. Very preterm infants had significantly lower scores on the Mental Development Index (MDI) and Psychomotor Development Index (PDI) on the Bayley Scales of Infant Development (BSID II), however when this was partialled out the differences in EF scores remained. Medical complications, lower birthweight and lower gestation age were all found to adversely affect the performance of very preterm infants on executive function tasks.

Conclusion

Very preterm infants performed more poorly than full-term infants on measures of EF. Further follow up studies are required to investigate whether EF measures in infancy can predict learning and attention outcome at school age.     

The effect of postnatal age on the early tactile manual abilities of preterm infants

Background

Although preterm infants possess early tactile manual abilities, the influence of the postnatal experience has not yet been systematically examined.

Aims

To investigate whether early tactile manual habituation, discrimination and recognition (following interference) of shape in preterm infants are modified by postnatal age.

Study design

Prospective study.

Subjects

Forty preterm infants were assessed from the post-conceptional age (PCA) of 34 weeks. Two groups were made up according to postnatal age (PNA): low PNA (PNA ≤ 10 days of life) and high PNA (PNA ≥ 12 days of life).

Outcome measures

An object (prism or cylinder) was presented repeatedly in the left hand, and holding times of the object were recorded during each trial.

Results

Holding time was shorter for all preterm infants following successive presentation of the same object irrespective of postnatal age range. In the discrimination phase, the mean holding time for the novel object was longer than holding times in the last two habituation trials, in both PNA groups. Finally, the mean holding time of the familiar object presented in the recognition phase was shorter than the holding time of the novel object presented previously, but only in the low PNA group.

Conclusions

Tactile manual habituation and discrimination of shape information is present in preterm infants at a post-conceptional age of 34 weeks, independently of postnatal age. However, tactile manual recognition of familiar shapes following interference is affected by length of postnatal experience. The significance of this last result is discussed in detail.     

Heart rate variability during caregiving and sleep after massage therapy in preterm infants

Background

Preterm birth impairs the infant's stress response due to interruption of autonomic nervous system (ANS) development. Preterm infants demonstrate a prolonged and aberrant sympathetic response to stressors. ANS development may be promoted by massage therapy (MT), which has been shown to improve stress response in preterm infants.

Aims

The aim of this study was to compare preterm infant ANS function and stress response during sleep and caregiving epochs, as measured by heart rate variability (HRV), after two weeks of twice-daily MT.

Study design

A subset of participants from a larger randomized, masked, controlled trial was used.

Subjects

Twenty-one infants (8 males and 13 females) from a larger study of 37 medically stable preterm infants were studied. The infants were receiving full volume enteral feedings with a mean post-menstrual age of 31.4 (MT) and 30.9 (control) weeks.

Outcome measures

Low to high frequency (LF:HF) ratio of HRV was the outcome of interest.

Results

There was a significant group × time × sex interaction effect (p < .05). Male control infants demonstrated a significant decline in LF:HF ratio from baseline to the second caregiving epoch, suggesting decreased mobilization of sympathetic nervous system response when exposed to stressors. Male MT infants demonstrated increased LF:HF ratio during caregiving and decreased LF:HF ratio during sleep epochs, suggesting improved ANS function, although this was not statistically significant. LF:HF ratio was similar in female MT and female control infants during caregiving and sleep.

Conclusions

Control males had decreased HRV compared to MT males. There was no difference in HRV between MT and control females.