Assessment of gestational age and neuromaturation

Multiscale Coupling of Uterine Electromyography and Fetal Heart Rate as a Novel Indicator of Fetal Neural Development

Fetal nerve maturation is a dynamic process, which is reflected in fetal movement and fetal heart rate (FHR) patterns. Classical FHR variability (fHRV) indices cannot fully reflect their complex interrelationship. This study aims to provide an alternative insight for fetal neural development by using the coupling analysis of uterine electromyography (UEMG) and FHR acceleration. We investigated 39 normal pregnancies with appropriate for gestational age (AGA) and 19 high-risk pregnancies with small for gestational age (SGA) at 28-39 weeks. The UEMG and FHR were recorded simultaneously by a trans-abdominal device during the night (10 p.m.-8 a.m.). Cross-wavelet analysis was used to characterize the dynamic relationship between FHR and UEMG. Subsequently, a UEMG-FHR coupling index (UFCI) was extracted from the multiscale coupling power spectrum. We examined the gestational-age dependency of UFCI by linear/quadratic regression models, and the ability to screen for SGA using binary logistic regression. Also, the performances of classical fHRV indices, including short-term variation (STV), averaged acceleration capacity (AAC), and averaged deceleration capacity (ADC), time- and frequency- domain indices, and multiscale entropy (MSE), were compared as references on the same recordings. The results showed that UFCI provided a stronger age predicting value with R² = 0.480, in contrast to the best value among other fHRV indices with R² = 0.335, by univariate regression models. Also, UFCI achieved superior performance for predicting SGA with the area under the curve (AUC) of 0.88, compared with 0.79 for best performance of other fHRV indices. The present results indicate that UFCI provides new information for early detection and comprehensive interpretation of intrauterine growth restriction in prenatal diagnosis, and helps improve the screening of SGA.

Accurate prediction of gestational age using newborn screening analyte data

BACKGROUND

Identification of preterm births and accurate estimates of gestational age for newborn infants is vital to guide care. Unfortunately, in developing countries, it can be challenging to obtain estimates of gestational age. Routinely collected newborn infant screening metabolic analytes vary by gestational age and may be useful to estimate gestational age.

OBJECTIVE

We sought to develop an algorithm that could estimate gestational age at birth that is based on the analytes that are obtained from newborn infant screening.

STUDY DESIGN

We conducted a population-based cross-sectional study of all live births in the province of Ontario that included 249,700 infants who were born between April 2007 and March 2009 and who underwent newborn infant screening. We used multivariable linear and logistic regression analyses to build a model to predict gestational age using newborn infant screening metabolite measurements and readily available physical characteristics data (birthweight and sex).

RESULTS

The final model of our metabolic gestational dating algorithm had an average deviation between observed and expected gestational age of approximately 1 week, which suggests excellent predictive ability (adjusted R-square of 0.65; root mean square error, 1.06 weeks). Two-thirds of the gestational ages that were predicted by our model were accurate within ±1 week of the actual gestational age. Our logistic regression model was able to discriminate extremely well between term and increasingly premature categories of infants (c-statistic, >0.99).

CONCLUSION

Metabolic gestational dating is accurate for the prediction of gestational age and could have value in low resource settings.

Changes of amplitude integration electroencephalogram (aEEG) in different maturity preterm infant

BACKGROUND

With the improvement of perinatal care and neonatal intensive care technology in recent years, a preterm infant, especially with small gestational age and very low birth weight, survives more and more. At the same time, adverse neurodevelopmental prognosis caused by brain damage in preterm infant also increased significantly. Preterm infant brain injury has become the most important factor for early death and neurodevelopment of preterm infant.

METHODS

Amplitude integration electroencephalogram (aEEG) has an important clinical value in the assessment of brain development in the maturity of preterm infant. With the application of a neonatal brain function monitor, we value the aEEG graphic continuity, periodicity, narrowband lower margin amplitude, and bandwidth score and analyze wide- and narrowband on the lower bounds of voltage and bandwidth.

RESULTS

The graphics of preterm infant aEEG become mature with the growth of the gestational age (1). With the growth of corrected gestational age, the aEEG graphics of preterm infant has the following feature: lower bound voltage of narrowband rising and width narrowing of narrowband (2). Extrauterine life can speed up the maturation of aEEG graphics (3).

CONCLUSIONS

The aEEG technology is a noninvasive, operable, and simple analysis and suitable for application in the newborn intensive care unit.

Challenges in defining and classifying the preterm birth syndrome

In 2009, the Global Alliance to Prevent Prematurity and Stillbirth Conference charged the authors to propose a new comprehensive, consistent, and uniform classification system for preterm birth. This first article reviews issues related to measurement of gestational age, clinical vs etiologic phenotypes, inclusion vs exclusion of multifetal and stillborn infants, and separation vs combination of pathways to preterm birth. The second article proposes answers to the questions raised here, and the third demonstrates how the proposed system might work in practice.

[Challenges in definition of gestational age in population studies on birth preterm: the case of a study in Campina Grande (PB), Brazil]

INTRODUCTION

The prevalence of preterm birth has increased in recent years and it is currently a worldwide public health problem. In any epidemiological study, the greatest challenge facing the study of preterm delivery is to standardize the measurement of gestational age births.

OBJECTIVE

To describe the methods used to define the sample under study and selection of events in case-control studies of risk factors for preterm birth in hospital births by mothers living in the city of Campina Grande (PB), Brazil.

METHODS

The design was a case-control population-based, which was conducted from June 2008 to May 2009. The cases were born at less than 37 weeks of gestation and controls at 37 weeks or more. Gestational age in weeks was defined using selection criteria based on the accuracy of the estimate. Interviews were conducted with mothers and collection of hospital records.

RESULTS

It was selected 341 cases and 424 controls, 13.19% were classified as extremely preterm (<28 weeks), 34.87% as very preterm (<33 weeks) and 65.10% as moderate preterm (33 to 36 weeks of gestation). Among controls, the percent of children born 37-39 weeks was 58.02 to 5.90% was born post term (>42 weeks).

CONCLUSION

The strategies shown to be viable, even in a context with major limitations in obtaining the necessary information, given that the profile of preterm infants, the distribution of gestational age were comparable to studies with more accurate methods.

Outcomes of preterm infants: morbidity replaces mortality

Over the last 50 years in the United States a rising preterm birth rate, a progressive decrease in preterm mortality, and a lowering of the limit of viability have made preterm birth a significant public health problem. Neuromaturation, the functional development of the central nervous system (CNS), is a dynamic process that promotes and shapes CNS structural development. This article reviews preterm outcomes, recognizing that multiple factors influence neuromaturation and lead to a range of neurodevelopmental disabilities, dysfunctions, and altered CNS processing. Ways to protect preterm infants and support their growth and development in and beyond intensive care are examined.

Extremely low birth weight preterm infants lack vasomotor response in relationship to cold body temperatures at birth

OBJECTIVE

This study evaluated peripheral vasoconstriction in extremely low birth weight (ELBW) infants when body temperature decreased during the first 12 h of life.

STUDY DESIGN

An exploratory, within-subjects design with 10 ELBW infants. Abdominal and foot temperatures were measured every minute. Peripheral vasoconstriction (abdominal>peripheral temperature by 2 degrees C) and abdominal-peripheral temperature difference were also evaluated.

RESULTS

Abdominal and peripheral temperatures were significantly correlated within each infant. One 880 g infant exhibited isolated peripheral vasoconstriction; a 960-g infant had abdominal temperatures >1 degrees C higher than peripheral temperatures. Eight smaller infants exhibited no peripheral vasoconstriction and spent most of their observations with peripheral greater than abdominal temperatures. In eight infants, mean temperature difference was significantly higher when abdominal temperature was <36.5 degrees C.

CONCLUSION

Most ELBW infants did not exhibit peripheral vasoconstriction during their first 12 h of life, despite low temperatures. ELBW infants' vasomotor control may be immature during this period.

Parental bilingualism is associated with slower cognitive development in very low birth weight infants

BACKGROUND

Speech development is frequently impaired in very low birth weight (VLBW) infants. Few and controversial data have been published on concepts regarding the influence of bilingual education.

AIMS

The objectives of the current study were to assess the influence of parental bilingualism on speech development and neurodevelopmental outcome in low risk VLBW infants.

STUDY DESIGN

Monocentric prospective controlled cohort study with standardized follow-up.

SUBJECTS

We recruited 50 singleton VLBW infants each from monolingual and bilingual families as well as 90 term control infants. The infants were free of disease and congenital malformation.

OUTCOME MEASURES

Griffiths scales of infant development at the corrected ages of 6 and 12 months, Bayley Scales of Infant Development II (BSID II) with 22 months.

RESULTS

In general, both bilingual and monolingual VLBW infants achieved age-specific milestones at the corrected age of 6, 12 and 22 months. However, bilingual VLBW infants achieved significantly lower scores than their monolingual peers in all cognitive subscales. The influence of maternal education on the neurodevelopmental outcome of the preterm infants was not significant; the subscales' correlation with socioeconomic or biological parameters was poor. However, a clear differentiation between social status and bilingual environment importance for speech development was not possible.

CONCLUSIONS

In the setting of the present investigation, parental bilingualism is associated with slower neurodevelopment in VLBW infants during the first 2 years of life.

Extrauterine neuromaturation of low risk preterm infants

The objective of the study was to follow neuromaturation in preterm infants. From serial exams in 90 low risk very low birthweight infants, each infant's Maturity Scores (the sum of tone, reflex, and response items) were plotted against postmenstrual age (PMA) when examined. Each infant's estimated line of best fit provides two descriptors of that infant's neuromaturation: slope (Individual Maturity Slope) and y-value (Predicted Maturity Score at 32-wk PMA). We found that Maturity Scores increased with PMA; 96% had correlation coefficients >0.8. Mean Actual and Predicted Maturity Scores at 32-wk PMA were 60 and 58, respectively, in 65 infants. When stratified by gestational age, Mean Actual Maturity Score at 30-wk PMA were 50 whether infants were 1 or several weeks old when examined. Therefore, low risk preterm infants demonstrated individual variability in rate of neuromaturation. Tone, reflexes, and responses nonetheless emerged in a predictable pattern, whether neuromaturation was intrauterine or extrauterine. This unique tool that measures preterm neuromaturation requires expertise but no technology. It has an exciting potential for providing insight into how emerging central nervous system function and structure influence each other, as well as how the central nervous system recovers from injury.

Ontogeny of EEG-sleep from neonatal through infancy periods

Serial neonatal and infant electroencephalographic (EEG)-polysomnographic studies document the ontogeny of cerebral and noncerebral physiologic behaviors based on visual inspection or computer analyses. EEG patterns and their relationship to other physiologic signals serve as templates for normal brain organization and maturation, subserving multiple interconnected neuronal networks. Interpretation of serial EEG-sleep patterns also helps track the continuity of brain functions from intrauterine to extrauterine time periods. Recognition of the ontogeny of behavioral and electrographic patterns provides insight into the developmental neurophysiological expression of neural plasticity. Sleep ontogenesis from neonatal and infancy periods documents expected patterns of postnatal brain maturation, which allows for alterations from genetically programmed neuronal processes under stressful and/or pathological conditions. Automated analyses of cerebral and noncerebral signals provide time- and frequency-dependent computational phenotypes of brain organization and maturation in healthy or diseased states. Research pertaining to the developmental origins of health and disease can use these computational phenotypes to design longitudinal studies for the assessment of gene-environment interactions. Computational strategies may ultimately improve our diagnostic skills to identify special-needs children and to track the neurorehabilitative care of the high-risk fetus, neonate, and infant.

Gestational age estimation on United States livebirth certificates: a historical overview

Gestational age on the birth certificate is the most common source of population-based gestational age data that informs public health policy and practice in the US. Last menstrual period is one of the oldest methods of gestational age estimation and has been on the US Standard Certificate of Live Birth since 1968. The 'clinical estimate of gestation', added to the standard certificate in 1989 to address missing or erroneous last menstrual period data, was replaced by the 'obstetric estimate of gestation' on the 2003 revision, which specifically precludes neonatal assessments. We discuss the strengths and weaknesses of these measures, potential research implications and challenges accompanying the transition to the obstetric estimate.

Towards creation of a unified view of the neurodevelopment of the infant

During the twentieth century, study of the neurologic development of the fetus and infant has resulted in multiple neurodevelopmental assessments. They have been used both for determination of the integrity of the neonate as well as for assessment of the child's outcome from prenatal and neonatal medical interventions. These models of assessment have broadened our view and understanding of the development of functions such as movement, posture, attention, oromotor skills, and behavior. The link between these areas and the traditional areas of neurologic and psychiatric examination of older children and adults is explored through discussion of the maturation of movement, cranial nerve function, sensory, cognitive, and behavioral responses. Gaps in knowledge remain about the relationship between early neurodevelopmental assessments and later findings. A single unified means of examining the infant is also lacking.