The potential of four-dimensional (4D) ultrasonography in the assessment of fetal awareness

Tail movements by late-term fetal pitvipers resemble caudal luring: prenatal development of an ambush predatory behaviour

With the advent of powerful imaging instruments, the prenatal behaviour of vertebrates has been discovered to be far more complex than previously believed, especially concerning humans, other mammals and birds. Surprisingly, the fetal behaviour of squamate reptiles (lizards, snakes and amphisbaenians), a group of over 11 000 extant species, are largely understudied. Using ultrasonography, 18 late-term pregnant copperhead snakes (Agkistrodon contortrix) from a single population were inspected for fecundity (number of fetuses). Unexpectedly, during the ultrasound procedure that involved 97 fetuses, we observed sinusoidal tail movements in 11 individuals from eight different copperhead mothers. These movements were indistinguishable from caudal luring, a mimetic ambush predatory strategy which is exhibited by newborn copperheads and other snakes. Caudal luring is initiated shortly after birth and is employed to attract susceptible vertebrate prey. Using the same ultrasound equipment and methods, we tested for this behaviour in two species of rattlesnakes (genus Crotalus) not known to caudal lure and none of the late-term fetuses showed any type of tail movements. Prenatal movements in humans and other vertebrates are known to be important for musculoskeletal and sensorimotor development. The fetal behaviours we describe for copperheads, and possibly other snakes, may be similarly important and influence early survival and subsequent fitness.

Effect of psychotropic drugs on fetal behavior in the third trimester of pregnancy

AIM

To assess the effect of psychotropic drugs on fetal behavior using four-dimensional (4D) ultrasound in the third trimester of pregnancy.

METHODS

Fetal behavior was assessed using Kurjak's antenatal neurodevelopmental test (KANET) using 4D ultrasound between 28 and 36 weeks of gestation. Thirty healthy (control group) and 10 psychotropic-drug-administered pregnant (case group) women were studied. The total value of the KANET score and values of each parameter (eight parameters) were compared between the two groups.

RESULTS

The total KANET score was normal (except for one fetus in the case group: total score of 9) in both groups, and there was no significant difference in the total KANET score. When individual KANET parameters were compared, no significant differences were noted in any of the eight parameters.

CONCLUSION

Our results showed that there is no difference in fetal behavior between fetuses of normal pregnant women and those of psychotropic-drug-administered pregnant women in the third trimester of pregnancy. These results suggest that psychotropic drugs may not affect fetal behavioral development in utero. However, the data and their interpretation in the present study should be taken with some degree of caution because of the small number of subjects studied. Further studies involving a larger sample size are needed to assess the effect of psychotropic drugs on fetal neurobehavior during pregnancy.

Ultrasound study of fetal movements in singleton and twin pregnancies at 12-19 weeks

Objective To evaluate fetal behavioral differences between singleton and twin fetuses before 20 weeks of gestation using four-dimensional (4D) ultrasound. Methods 4D ultrasound was used to examine fetal movements in 58 singleton and 48 twin normal fetuses at 12-19 weeks. The frequencies of eight fetal movements were assessed through 15-min recordings. The fetuses were divided into two gestational age groups (12-13 and 14-19 weeks) to evaluate the changes with advancing gestation in twin versus singleton fetuses. Results Arm and general movements were the most frequent movements in singleton fetuses, whereas only general movement was significantly more frequent than the other seven fetal movements in twin fetuses at 12-13 weeks. At 14-19 weeks, frequencies of arm and leg movements were significantly higher than those of the other six movements in singleton fetuses, while only arm movement was significantly more frequent than the other fetal movements in twin fetuses. Comparisons of fetal movements between singleton and twin fetuses revealed that only arm movement showed a significant difference at 12-13 weeks, while the frequencies of all movements in singleton fetuses were significantly higher than those in twin fetuses at 14-19 weeks. Conclusion Our results suggest that the limitation of available space and crowding of twin fetuses with advancing gestation may have a marked impact on twin fetal movements compared with singleton fetuses, even in the first half of pregnancy. Further studies are needed to assess whether decreased fetal movements in twin pregnancy can affect fetal and neonatal development and maturation before and after birth.

4D ultrasound study of fetal facial expressions in the third trimester of pregnancy

OBJECTIVE

To evaluate the frequencies of fetal facial expressions in the third trimester of pregnancy, when fetal brain maturation and development are progressing in normal healthy fetuses.

METHODS

Four-dimensional (4 D) ultrasound was used to examine the facial expressions of 111 healthy fetuses between 30 and 40 weeks of gestation. The frequencies of seven facial expressions (mouthing, yawning, smiling, tongue expulsion, scowling, sucking, and blinking) during 15-minute recordings were assessed. The fetuses were further divided into three gestational age groups (25 fetuses at 30-31 weeks, 43 at 32-35 weeks, and 43 at ≥36 weeks). Comparison of facial expressions among the three gestational age groups was performed to determine their changes with advancing gestation.

RESULTS

Mouthing was the most frequent facial expression at 30-40 weeks of gestation, followed by blinking. Both facial expressions were significantly more frequent than the other expressions (p < .05). The frequency of yawning decreased with the gestational age after 30 weeks of gestation (p = .031). Other facial expressions did not change between 30 and 40 weeks. The frequency of yawning at 30-31 weeks was significantly higher than that at 36-40 weeks (p < .05). There were no significant differences in the other facial expressions among the three gestational age groups.

CONCLUSIONS

Our results suggest that 4D ultrasound assessment of fetal facial expressions may be a useful modality for evaluating fetal brain maturation and development. The decreasing frequency of fetal yawning after 30 weeks of gestation may explain the emergence of distinct states of arousal.

Is fetal analgesia necessary during prenatal surgery?

Fetal pain and fetal anesthesia are still matter of debate: some authors hypothesize that several intrauterine endocrine neuroinhibitors (ENIn) anesthetize the fetus, keeping it in a constant state of sleep, and making pharmacological fetal anesthesia useless for fetal surgery, while others argue fetal pain is possible and shoud be prevented with fetal anesthesy.

AIM

To retrieve evidences about fetal pain, fetal arousability and about the level of sedation induced by the ENIn, in order to assess the necessity of direct fetal anesthesia during prenatal fetal surgery.

METHODS

We performed a careful literature review (1990-2016) on fetal arousability, and on the possibility that ENIn at the average fetal blood levels induce actual anesthesia. We retrieved the papers that fulfilled the research criteria, with particular attention to the second half of pregnancy, the period when most fetal surgery is performed.

RESULTS

Fetuses are awake about 10% of the total time in the last gestational weeks, and they can be aroused by external stimuli. ENIn have not an anesthetic effect at normal fetal values, but only when they areartificialy injected at high doses; their blood levels in the last trimester of average pregnancies are not dissimilar either in the fetus or in the mother.

CONCLUSIONS

During the second half of the pregnancy, external stimuli can awake the fetuses, although they spend most of the time in sleeping state; the presence of ENIn is absolutely not enough to guarantee an effective anesthesia during surgery. Thus, direct fetal analgesia/anesthesia is mandatory, though further studies on its possible drawbacks are necessary.

The organization and reorganization of audiovisual speech perception in the first year of life

The period between six and 12 months is a sensitive period for language learning during which infants undergo auditory perceptual attunement, and recent results indicate that this sensitive period may exist across sensory modalities. We tested infants at three stages of perceptual attunement (six, nine, and 11 months) to determine 1) whether they were sensitive to the congruence between heard and seen speech stimuli in an unfamiliar language, and 2) whether familiarization with congruent audiovisual speech could boost subsequent non-native auditory discrimination. Infants at six- and nine-, but not 11-months, detected audiovisual congruence of non-native syllables. Familiarization to incongruent, but not congruent, audiovisual speech changed auditory discrimination at test for six-month-olds but not nine- or 11-month-olds. These results advance the proposal that speech perception is audiovisual from early in ontogeny, and that the sensitive period for audiovisual speech perception may last somewhat longer than that for auditory perception alone.

Current status of fetal neurodevelopmental assessment: Four-dimensional ultrasound study

With the latest advent of four-dimensional (4-D) ultrasound, fetal neurobehavioral or neurodevelopmental assessment can be easily and readily performed. Using this technique, typical fetal movements and behavioral patterns have become apparent in all three trimesters of pregnancy. In twin pregnancy, 4-D ultrasound facilitates the precise evaluation of inter-twin contact and intra-pair stimulation. New fetal neurobehavioral assessment tests, such as Kurjak's Antenatal Neurodevelopmental Test and the Fetal Observable Movement System, may reflect the normal and abnormal neurological development of the fetus, and will facilitate more precise assessments of fetal neurobehavior or neurodevelopment, and fetal brain and central nervous system functions. In this review article, I also discuss interesting topics regarding maternal and fetal stress, fetal pain, and fetal consciousness. Four-dimensional ultrasound has opened the door to new scientific fields, such as 'fetal neurology' and 'fetal psychology,' and fetal neurobehavioral science is at the dawn of a new era. Knowledge on fetal neurobehavior and neurodevelopment will be advanced through fetal behavioral research using this technique.

Antenatal and Postnatal Assessment of Neurobehavior: Which One should be used?

It is obvious that this environment is quite different from one man is experiencing after birth, but, although different, intrauterine environment is ideal at that stage of human development. There is a question of the environmental discontinuity between intrauterine conditions characterized by existence of microgravity (baby astronaut hypothesis), and extrauterine life with gravity as developmental condition sine qua non. The human brain is one of the organs which is very sensitive to environmental changes affecting its growth and development. The brain of very tiny prematurely born babies is unable to follow the genetically determined growth pattern in extrauterine environment, even when postnatal nutrition and nurturing of the babies according to our best knowledge are appropriate. Is this fact of any significance to make distinction between normal and abnormal neurodevelopment pre- and postnatally is still unclear?

Kurjak antenatal neurodevelopmental test (KANET) using four-dimensional ultrasound (4D US) has been introduced using ten parameters and after attempt of standardization only eight parameters remained for neurodevelopmental assessment of low- and high-risk fetuses. We believe that at present level of knowledge, KANET test could be considered as a good test for the detection of fetuses with high neurological risk, without the possibility to define reliable long-term neurodevelopmental outcome. This is also hardly possible based on postnatal neurological assessment with 27 different postnatal tests. They were primarily neurobehavioral or neuromotor assessments that were suitable for use with preterm infants, and were discriminative, predictive or evaluative.

There was a high willingness of clinician to find postnatal neurodevelopmental test which could be predictive for short- term and long-term outcome of low and high-risk infants.

Although, there are many tests available for prenatal and postnatal assessment of neurodevelopment, none of them is reliable in the prediction of neurodevelopmental outcome in low-risk population, while many could be used with fairly acceptable predictivity in high-risk population. Although, many studies have been conducted in order to solve this problem, still there is a space for improvement. In postnatal period we are dealing with infant in front of the clinician with direct observation, while pretnatally we are dealing with quite different environment and less mature brain.

How to cite this article

Stanojevic M. Antenatal and Postnatal Assessment of Neurobehavior: Which One should be used? Donald School J Ultrasound Obstet Gynecol 2015;9(1):67-74.

Fetal Consciousness: Four-dimensional Ultrasound Study

How to cite this article

Hata T, Kanenishi K, AboEllail MAM, Marumo G, Kurjak A. Fetal Consciousness: Four-dimensional Ultrasound Study. Donald School J Ultrasound Obstet Gynecol 2015;9(4):471-474.

Fetal Neurology: Past, Present and Future

Neurological failure is the most apprehension complication of pregnancy, labor and the neonatal period. The origin and outcome correlation is frequently doubtful. The arrival of four-dimensional ultrasonography (4D US) and its function to study fetal behavior patterns have initiated to offer insight into the structural and functional fetal brain development. Although many fetal behavioral studies have been conducted, it is still questionable whether the assessment of continuity from fetal to neonatal behavior could improve our ability of early detection of brain pathology. Neurological assessment of fetus in utero is extremely difficult even having such sophisticated equipment like 4D ultrasound. As it is well known that quantity of GMs is not so informative and predictive for neurological impairment, their quality should be assessed. Gestalt perception of premature GMs we are dealing with in utero and several weeks postnatally are not as predictive for the detection of neurologically abnormal fetuses or newborns as fidgety GMs. Therefore, some additional parameters should be added to the prenatal neurological examination in order to improve our ability to make the distinction between normal and abnormal fetuses.

How to cite this article

Kurjak A, Antsaklis P, Stanojevic M. Fetal Neurology: Past, Present and Future. Donald School J Ultrasound Obstet Gynecol 2015;9(1):6-29.

Is in utero Fetal Neurological Assessment Comparable to Postnatal Neurological Assessment?

The traditional concept that brain damage is caused during birth or early neonatal period has been challenged. This is supported by the fact that the incidence of cerebral palsy stayed unchanged despite the global increase of cesarean sections. Consequently, the medicolegal importance of fetal neurological research is essential and needed. Years of research have provided us with important knowledge about association of fetal movements with brain development. The basic studies were done by two-dimensional ultrasound. The implementation of four-dimensional ultrasound in evaluation of fetal behavior has opened new and unexplored possibilities of evaluating the quality of fetal movements and a detailed assessment of fetal facial expressions. It is known that early postnatal neurological assessment, regarding future prediction of neurological optimality, has great limitations do to wonderful brain plasticity. Taking this very important limitation in to the account we could conclude that the preliminary studies comparing prenatal and postnatal neurological assessment are comparable. More importantly they emphasize the fact that the study of fetal behavior is most probably the right path in the study of fetal neurological development.

How to cite this article

Vasilj O. Is in utero Fetal Neurological Assessment Comparable to Postnatal Neurological Assessment? Donald School J Ultrasound Obstet Gynecol 2015; 9(1):91-95.

HDlive and 4D Ultrasound in the Assessment of Fetal Facial Expressions

Four-dimensional (4D) sonographic assessment of fetal facial expressions is considered to reflect normal and abnormal fetal neurological developments, and may be an important clue to predict the fetal brain function and well-being before and after birth. HDlive is a new surface-rendering mode, which uses an adjustable light source that facilitates the ability to create lighting and shadowing effects, thereby increasing depth perception. This technique facilitates extraordinarily realistic imaging of the fetal face, making it almost impossible to differentiate between actual photographs and HDlive images. In this article, we discuss recent topics regarding fetal facial expressions assessed by 4D ultrasound and HDlive, focusing on mouthing, sucking, yawning, blinking, tongue expulsion, scowling (pain/distress), and smiling. Moreover, we consider possibility of the existence of fetal emotion or awareness.

How to cite this article

Hata T, Kanenishi K, Hanaoka U, Marumo G. HDlive and 4D Ultrasound in the Assessment of Fetal Facial Expressions. Donald School J Ultrasound Obstet Gynecol 2015;9(1):44-50.

Assessment of fetal behavior using four-dimensional ultrasonography: current knowledge and perspectives

In the last decades, the development of real-time ultrasonography has allowed the direct view of the fetus in the uterus, as well as assessing its activity. The advent of three-dimensional ultrasonography (3D) at the end of the 80s initiated a new era in diagnostic imaging for Obstetrics, dramatically increasing the possibility of studying the fetus. Recently, a new technique allowing the 3D image to be transformed into real-time was introduced: the four-dimensional (4D) ultrasonography. It allows the continuous monitoring of fetal face and other surface areas, such as the extremities. Some studies have already assessed this new methodology for fetal behavior observation during different stages of pregnancy, trying to understand better the relationship between fetal central nervous system maturation and the implications for its behavior. In this article, the authors review the current use of 4D ultrasonography in the assessment of fetal behavior, and discuss the possibilities of the technique to show the neurological development of the fetus, by means of watching movement and facial expressions. They also highlight the potential applicability of this new method in this new research area of fetal medicine.

Can healthy fetuses show facial expressions of "pain" or "distress"?

BACKGROUND

With advances of research on fetal behavioural development, the question of whether we can identify fetal facial expressions and determine their developmental progression, takes on greater importance. In this study we investigate longitudinally the increasing complexity of combinations of facial movements from 24 to 36 weeks gestation in a sample of healthy fetuses using frame-by-frame coding of 4-D ultrasound scans. The primary aim was to examine whether these complex facial movements coalesce into a recognisable facial expression of pain/distress.

METHODOLOGY/FINDINGS

Fifteen fetuses (8 girls, 7 boys) were observed four times in the second and third trimester of pregnancy. Fetuses showed significant progress towards more complex facial expressions as gestational age increased. Statistical analysis of the facial movements making up a specific facial configuration namely "pain/distress" also demonstrates that this facial expression becomes significantly more complete as the fetus matures.

CONCLUSIONS/SIGNIFICANCE

The study shows that one can determine the normal progression of fetal facial movements. Furthermore, our results suggest that healthy fetuses progress towards an increasingly complete pain/distress expression as they mature. We argue that this is an adaptive process which is beneficial to the fetus postnatally and has the potential to identify normal versus abnormal developmental pathways.

Four-dimensional HDlive rendering image of fetal facial expression: a pictorial essay

BACKGROUND

Our objective was to present our experience of fetal facial expressions reconstructed employing the four-dimensional (4D) HDlive rendering mode.

METHODS

A total of 23 normal fetuses at 18-36 weeks' gestation were studied using the 4D HDlive rendering mode.

RESULTS

The 4D HDlive rendering mode provided extraordinarily realistic features of the fetal face. In particular, blinking, mouthing, swallowing, yawning, tongue expulsion, and sucking were clearly noted. Moreover, various realistic fetal emotional expressions such as smiling-like and crying-like movements were recognized. The 4D HDlive rendered images of fetal facial expressions seem to be more readily discernible than those obtained by conventional 4D ultrasonography.

CONCLUSION

Observation of facial expressions using the 4D HDlive rendering mode is considered to reflect the normal and abnormal neurological development of the fetus. Therefore, the 4D HDlive rendering mode may assist in evaluation of fetal brain function, and offer potential advantages relative to conventional 4D ultrasonography.

4D Ultrasound - Medical Devices for Recent Advances on the Etiology of Cerebral Palsy

Children cerebral palsy (CCP) encompasses a group of nonprogessive and noninfectious conditions, which cause light, moderate, and severe deviations in neurological development. Diagnosis of CCP is set mostly by the age of 3 years. The fact that a large number of cerebral damage occurs prenatally and the fact that early intervention in cases of neurological damage is successful, prompted some researchers to explore the possibility of detecting neurologically damaged fetus in the uterus. This research was made possible thanks to the development of two-dimensional ultrasound technology in a real time, which enabled the display of the mobility of the fetus. Advancement of the ultrasound technology has enabled the development of 4D ultrasound where a spontaneous fetal movement can be observed almost in a real time. Estimate of the number and quality of spontaneous fetal movements and stitches on the head, the neurology thumb and a high palate were included in the prenatal neurological screening of the fetus. This raises the question, as to does the fetal behavior reflect, (which was revealed in 2D or 4D ultrasound), fetal neurological development in a manner that will allow the detection of the brain damage.

Magnetic resonance methods in fetal neurology

Fetal magnetic resonance imaging (MRI) has become an established clinical adjunct for the in-vivo evaluation of human brain development. Normal fetal brain maturation can be studied with MRI from the 18th week of gestation to term and relies primarily on T2-weighted sequences. Recently diffusion-weighted sequences have gained importance in the structural assessment of the fetal brain. Diffusion-weighted imaging provides quantitative information about water motion and tissue microstructure and has applications for both developmental and destructive brain processes. Advanced magnetic resonance techniques, such as spectroscopy, might be used to demonstrate metabolites that are involved in brain maturation, though their development is still in the early stages. Using fetal MRI in addition to prenatal ultrasound, morphological, metabolic, and functional assessment of the fetus can be achieved. The latter is not only based on observation of fetal movements as an indirect sign of activity of the fetal brain but also on direct visualization of fetal brain activity, adding a new component to fetal neurology. This article provides an overview of the MRI methods used for fetal neurologic evaluation, focusing on normal and abnormal early brain development.

4D Sonographic Assessment of Intertwin Contacts

Objective

To assess the onset and frequency of first interfetal contacts by 4D sonography.

Subjects and methods

Twenty twin pregnancies were scanned transvaginally between 56 (8 weeks) and 69 postmenstrual days (9+6 weeks) and onward transabdominally, at weekly intervals until 112 postmenstrual days (16 weeks). Scans were recorded on DVD and analyzed retrospectively. The moment of onset, type and frequency of intertwin contacts were assessed.

Results

First interhuman contacts were observed between 61 (8+5 weeks) and 68 (9+5 weeks) postmenstrual days. The frequency of different movements varied according to the gestational age. ‘Touch no reaction’ and ‘First reaction’ were common and frequent from 70 postmenstrual days (10 weeks) onward. ‘Slow body movements’ were more common than ‘Fast body movements’. ‘Complex contacts’ were more frequent at 94 postmenstrual days (13+3 weeks). Simple contacts diminished around 100 postmenstrual days (14+2 weeks). ‘Complex contacts’ and ‘diffuse interactions’ were more commonly observed between 105 (15 weeks) and 112 postmenstrual days (16 weeks). No significant differences were found when different gender combinations were compared.

Conclusion

Intertwin contacts start as soon as 8+5 weeks of gestation and complex or diffuse interactions are already seen at 15 to 16 weeks of gestation.

How to cite this article

Prats P, Serra B, Fournier S, Baulies S, Andonotopo W, Kurjak A. 4D Sonographic Assessment of Intertwin Contacts. Donald School J Ultrasound Obstet Gynecol 2012;6(2):154-159.

Intrauterine growth restriction and cerebral palsy

Intrauterine growth restriction (IUGR) can be described as condition in which fetus fails to reach his potential growth. It is common diagnosis in obstetrics, and carries an increased risk of perinatal mortality and morbidity. Moreover, IUGR has lifelong implications on health, especially on neurological outcome. There is a need for additional neurological assessment during monitoring of fetal well-being, in order to better predict antenatally which fetuses are at risk for adverse neurological outcome. Studies have revealed that the behavior of the fetus reflects the maturational processes of the central nervous system (CNS). Hence, ultrasound investigation of the fetal behavior can give us insight into the integrity and functioning of the fetal CNS. Furthermore, investigations carried out using modern method, four-dimensional (4D) sonography, have produced invaluable details of fetal behavior and its development, opening the door to a better understanding of the prenatal functional development of the CNS. Based on previous observations and several years of investigation, our reaserch group has proposed a new scoring system for the assessment of fetal neurological status by 4D sonography named Kurjak antenatal neurodevelopmental test (KANET). The value of KANET in distinguishing fetal brain and neurodevelopmental alterations due to the early brain impairment in utero is yet to be assessed in large population studies. However, preliminary results are very encouraging.

4D Sonography in Assessment of Fetal Neurobehavior

‘Observation of fetal behavior reflects the functioning of the central nervous system, and behavioral assessment of the fetus enables the function of the brain to be examined’.1 The introduction of four-dimensional (4D) sonography techniques would facilitate fetal behavioral assessment in three dimensions in real time during pregnancy. We describe the latest 4D sonographic studies on fetal neurobehavior in all three trimesters of pregnancy. 4D sonography also facilitated the evaluation of interhuman contact and intrapair stimulation in twin pregnancies in utero. This novel technique may assist in the evaluation of fetal neurobehavior and intertwin contact and intrapair stimulation and offer potential advantages relative to conventional two-dimensional sonography. 4D sonography may become an important modality in future research on fetal neurobehavioral development and the prenatal identification of severely brain-damaged infants.

How to cite this article

Hata T, Sato M, Kanenishi K, Hanaoka U, Tanaka H. 4D Sonography in Assessment of Fetal Neurobehavior. Donald School J Ultrasound Obstet Gynecol 2012;6(2):121-131.

Ultrasound Assessment of Fetal Neurobehavior in High-risk Pregnancies

Objectives

Assessment of the fetal behavior in normal and high-risk pregnancy during second and third trimesters.

Materials and methods

The study group included 61 healthy pregnant women and 135 pregnant women with high-risk pregnancy between 24 and 38 weeks of gestation for a period of 3 years (January 2009-May 2011). After 4D ultrasound examination we applied antenatal neurological score KANET 1. Score is considered normal between 14 and 20, borderline between 6 and 13 and abnormal between 0 and 5.

Results

The Kurjak antenatal neurological test (KANET) scores have significant differences, when applied on the two groups of pregnant women. Most fetuses who obtained normal KANET score were found in normal pregnancies, those who obtained borderline score were fetuses with intrauterine growth restriction (IUGR) with increased resistance index (RI) of middle cerebral artery (ACM) and the most fetuses with abnormal KANET score came from pregnancies complicated by threatened preterm delivery with PPROM.

Conclusion

Dynamic evaluation of fetal behavior reflects directly the processes of maturation and development of the central nervous system. This can make the difference between normal and abnormal brain development and may be used for early diagnosis of neurological disorders that become manifest in perinatal and postnatal periods.

How to cite this article

Vladareanu R, Lebit D, Constantinescu S. Ultrasound Assessment of Fetal Neurobehavior in High-risk Pregnancies. Donald School J Ultrasound Obstet Gynecol 2012;6(2):132-147.

Neurobehavioral continuity from fetus to neonate

Neurobehavior represents development of the central nervous system (CNS). Fetuses and newborns exhibit a large number of endogenously generated motor patterns, among which general movements are often investigated pre- and post-natally. Spontaneous activity is probably a more sensitive indicator of brain dysfunction than reactivity to sensory stimuli while testing reflexes. Nutritional stress at critical times during fetal development can have persistent and potentially irreversible effects particularly on brain growth and function. Unfavorable intrauterine environment can affect adversely brain growth. All endogenously generated movement patterns from un-stimulated CNS might be observed as early as from the seven to eight weeks' gestation, with a rich repertoire of movements within the next two or three weeks, continuing for five to six months postnatally. It is still uncertain whether a new scoring system for prenatal neurological assessment will be adequate for the distinction between normal and abnormal fetuses in low-risk pregnancies. The continuity of behavioral patterns from prenatal to postnatal life might answer these intriguing questions.

An Attempt to Standardize Kurjak's Antenatal Neurodevelopmental Test: Osaka Consensus Statement

Analysis of the dynamics of fetal behavior in comparison with morphological studies has led to the conclusion that fetal behavioral patterns are directly reflecting developmental and maturational processes of fetal central nervous system (CNS). Four-dimensional ultrasound (4D US) offers a practical means for assessment of both the brain function and structure. The visualization of fetal activity in utero by 4D US could allow distinction between normal and abnormal behavioral patterns which might make possible the early recognition of fetal brain impairment. That new technology enabled introduction of Kurjak's antenatal neurodevelopmental test (KANET) in low- and high-risk pregnancies. In order to make the test reproducible, the standardization of the test was proposed in Osaka, Japan, during the International Symposium on Fetal Neurology of International Academy of Perinatal Medicine.

The KANET should be performed in the 3rd trimester from 28th to 38th week of gestation. The assessment should last from 15 to 20 minutes, and the fetuses should be examined when awake. If the fetus is sleeping, the assessment should be postponed for 30 minutes or for the next day between 14 and 16 hours. In cases of definitely abnormal or borderline score, the test should be repeated every two weeks till delivery. New modified KANET test should be used with eight instead of 10 parameters: Facial and mouth movements are combined in one category, isolated hand movements and hand to face movements are combined in one category. The score should be the same for abnormal fetuses 0 to 5, borderline score is from 6 to 13 and normal score is 14 or above.

After 4D US assessment of behavioral patterns in the fetuses from high-risk pregnancies, it is very important to continue with follow-up after delivery in infants who were borderline or abnormal as fetuses. Postnatal assessment of neonates includes initial neurological assessment according to Amiel-Tison's methodology (Amiel-Tison Neurological Assessment at Term, ATNAT) in the early neonatal period and every two weeks in preterm infants till discharge and at the postmenstrual age (PMA) between 37 and 40 weeks. If ATNAT is borderline or abnormal, initial assessment of general movements at the age of 36 to 38 weeks of PMA should be performed, than at writhing age (between 46 and 52 weeks), and at the fidgety age after 54 weeks of PMA. If the finding of fidgety movements is mildly abnormal or definitely abnormal, then one more assessment should be done in 2 to 4 weeks till PMA of 58 weeks. Brain ultrasonography should be performed in the first week of life and every 2 weeks afterward till discharge. In severely affected infants with grade 3 and above intraventricular hemorrhage, and those highly suspicious of hypoxic ischemic brain damage, magnetic resonance (MR) should be done if available. Infants should be followed until the age of at least 24 months when diagnosis of disabling or nondisabling cerebral palsy can be ultimately made. Infants with CP should be reassessed at the age of 6 years.

Four-dimensional Ultrasound Evaluation of Fetal Neurobehavioral Development

The introduction of four-dimensional (4D) ultrasound techniques would facilitate fetal behavioral assessment in three-dimensions in realtime during pregnancy. We describe the latest 4D sonographic studies on fetal behavior, especially fetal whole-body movements and facial expressions in all three trimesters of pregnancy and the continuation of behavior from the fetal to neonatal period. Moreover, we introduce a new scoring system (KANET, Kurjak Antenatal Neurological Test) for assessment of the fetal neurological status using 4D ultrasound. 4D ultrasound also facilitated the evaluation of inter-human contact in twin pregnancies in utero. This novel technique may assist in the evaluation of fetal behavior and inter-twin contact, and offer potential advantages relative to conventional two-dimensional ultrasound. 4D ultrasound should become an important modality in future research on fetal neurobehavioral development and the prenatal identification of severely brain-damaged infants. Further studies involving a larger sample size are needed to ascertain the role of 4D ultrasound in the evaluation of fetal neurobehavioral development.

Further Experience in the Clinical Assessment of Fetal Neurobehavior

Recent development of three-dimensional (3D) and four-dimensional ultrasound (4D) provided us with new possibilities to study fetal movements and behavior. Many studies have been conducted in order to provide information on specific movement pattern appearance in normal and high-risk fetus. This was the base for multicenter study on use of new scoring system for fetal neurobehavior which purpose is to recognize fetuses with increased risk for poor neurological outcome. The purpose of this paper is to give brief review on the use of 3D and 4D ultrasound in the assessment of fetal behavior.

Objectives

Define possibilities to study fetal movements and behavior by 3D and 4D ultrasound

Decribe new scoring system for neurobehavior in fetuses with increased risk for poor neurological outcome

Summarize behavioral perinatology research and potential clinical applications

Four-dimensional sonographic assessment of inter-twin contact late in the first trimester

OBJECTIVE

To evaluate the total number of inter-twin contacts between monochorionic diamniotic (MD) and dichorionic diamniotic (DD) twins using four-dimensional (4D) sonography late in the first trimester of pregnancy.

METHOD

Six MD and 8 DD pregnancies were studied for 30 minutes with 4D sonography at 10-11 and 12-13 weeks of gestation. A total of 10 types of inter-twin contact was evaluated.

RESULTS

There was a significant difference in the total number of all contacts between MD and DD twins at the 10-11 weeks of gestation (P<0.05). There was also a significant difference in the total number of contacts between 10-11 and 12-13 weeks of gestation in DD twins (P<0.05).

CONCLUSION

Four-dimensional sonography provides a means of evaluating inter-twin contact in the first trimester of pregnancy and could be an accurate and reliable tool in studies of inter-twin behavior.

Three-dimensional ultrasound in prenatal diagnosis

PURPOSE OF REVIEW

Several technological advances have greatly improved three-dimensional sonography, which have improved acquisition and display capabilities. This review describes these technical changes as well as current applications of 3D sonography in prenatal diagnosis.

RECENT FINDINGS

Recently published papers have emphasized the potential of getting a precise 'any plane of choice' from a three-dimensional volume, as a new way of scanning, based on the off-line analysis of a volume dataset. Surface mode has been used to demonstrate malformations and genetic diseases. The maximum rendering mode, which highlights bones, has great potential for imaging the nasal bones and the frontal bones with the metopic suture. Organ volume can be measured, but the utility of this in clinical practice remains to be determined. Three-dimensional ultrasound needs to be standardized.

SUMMARY

Three-dimensional ultrasonography is the most rapidly developing technique in fetal imaging. New features will permit the transition from the era of 'sonography in two-dimensional planes' to 'volume ultrasound'.

New scoring system for fetal neurobehavior assessed by three- and four-dimensional sonography

AIM

To produce a new scoring system for fetal neurobehavior based on prenatal assessment by 3D/4D sonography. We identified severely brain damaged infants and those with optimal neurological findings and compared fetal with neonatal findings.

RESULTS

The new scoring system was retrospectively applied in a group of 100 low-risk pregnancies. After delivery, postnatal neurological assessment was performed, and all neonates assessed as normal reached a score between 14 and 20, which we assumed to be a score of optimal neurological development. Subsequently, the same scoring system was applied in the group of 120 high-risk pregnancies in which, based on postnatal neurological findings, three subgroups of newborns were found: normal, mildly or moderately abnormal, and abnormal. Normal neonates had a prenatal score between 14 and 20, mildly or moderately abnormal neonates had a prenatal score of 5-13, whereas those infants who were assigned as neurologically abnormal had a prenatal score from 0-5.

CONCLUSION

A new scoring system for the assessment of neurological status for antenatal application is proposed, similar to the neonatal optimality test of Amiel-Tison. This preliminary work may help in detecting fetal brain and neurodevelopmental alterations due to in utero brain impairment.

Human Motor Behavior

The spontaneous movements of the newborn infant have a long prenatal history. From 8 weeks postmenstrual age onward the fetus moves in distinct motor patterns. There is no period of amorphic and random movements. The patterns are easily recognizable, as all of them can be seen after birth. The human neonate demonstrates a continuum of motor patterns from prenatal to early postnatal life. Around the 3rd month a major transformation of motor and sensory patterns occurs. This makes the infant more fit to meet the requirements of the extra-uterine environment. The developmental course of spontaneous movements during the first 20 weeks postterm age shows the emergence and disappearance of various movement patterns. The so-called general movements deserve special interest as they are in their altered quality a most reliable indicator of brain (dys)function with a specific prediction of later developing cerebral palsy.

An Attempt to Introduce Neurological Test for Fetus Based on 3D and 4D Sonography

Fetal neurology is a new challenging field. Brain damage often originates in fetal life. Early identification of this damage has implications for perinatal management; moreover documentation of such lesions is essential in case of litigation. In the last two decades, fetal imaging with 2-dimensional ultrasounds and conventional magnetic resonance imaging have made a major contribution in the identification of classic brain lesions and malformations. However, it is only recently with diffusion weight imaging that the whole spectrum of perinatal white matter injuries has been described in the neonate. The recent advances of 3DUS and 4DUS in exploring fetal motor behavior should support a better clinical description of the full spectrum of fetal damage. New neurological test (KANET) of the fetus recently suggested by us (Kurjak et al 2008) might be helpful in the assessment of fetal neurobehavior.

Continuity between Fetal and Neonatal Neurobehavior

As the development of the brain is unique and continuing process throughout the gestation and after birth, it is expected that there is also continuity of fetal and neonatal movements which are the best functional indicator of developmental processes of the brain. Understanding the relation between fetal and infant behavior and developmental processes of the brain in different periods of gestation may make achievable the distinction between normal and abnormal brain development. Epidemiological studies revealed that many neurologically impaired infants belong to low risk population, which means that they seemed to be developmentally normal as fetuses and as infants, while later childhood neurological disability was diagnosed. Which methods of neurological assessment are available for that purpose? Prenatally we have not many possibilities for neurological assessment, while postnatally the repertoire of diagnostic possibilities is increasing. Among the postnatally available methods for neurological assessment, the most important are: clinical neurological assessment, neuroimaging methods, assessment of general movements (GMs) and combinations. Postnatal neurological assessment is probably easier to perform than prenatal, by using a simple and suitable for everyday work screening clinical test with good reliability, specificity and sensitivity.

There is a possibility for the early and simple neurological assessment of the term and preterm newborns with the aim to detect associated risks and anticipate long-term outcome of the infant, and to establish a possible causative link between pregnancy course and neurodevelopmental outcome. The evaluation of infant's developmental optimality should be assessed in order to investigate whether the infant is neurologically normal or damaged. Neurological assessment at term by Amiel-Tison (ATNAT) is taking into account neurological maturation exploring so called lower subcortical system developing earlier from the reticular formation, vestibular nuclei and tectum, and upper cortical system developing from the corticospinal pathways.

Conventional acquisition neuroimaging techniques together with modern diffusion neuroimaging techniques can identify typical patterns of brain injury, even in the early course of the disease. However, even though highly suggestive, these patterns cannot be considered as pathognomonic. Nevertheless neuroimaging methods alone are not sufficient to predict the neurological outcome in neonates from highrisk population.

Prechtl stated that spontaneous motility, as the expression of spontaneous neural activity, is a marker of brain proper or disturbed function. The observation of unstimulated fetus or infant which is the result of spontaneous behavior without sensory stimulation is the best method to assess its central nervous system capacity. All endogenously generated movement patterns from un-stimulated central nervous system could be observed as early as from the 7-8 weeks of postmenstrual age, with developing a reach repertoire of movements within the next two or three weeks, continuing to be present for 5 to 6 months postnatally. This remarkable fact of the continuity of endogenously generated activity from prenatal to postnatal life is the great opportunity to find out those high-risk fetuses and infants in whom development of neurological impairment is emerging. The most important among those movements are GMs involving the whole body in a variable sequence of arm, leg, neck and trunk movements, with gradual beginning and the end. They wax and wane in intensity, force and speed being fluent and elegant with the impression of complexity and variability. Assessment of GMs in high-risk newborns has significantly higher predictive value for later neurological development than neurological examination. Kurjak and co-workers conducted a study by 4D ultrasound and confirmed earlier findings made by 2D ultrasonography, that there is behavioral pattern continuity from prenatal to postnatal life. Assessment of neonatal behavior is a better method for early detection of cerebral palsy than neurological examination alone.

Are we approaching the era when there will be applicable neurological test for fetus and assessment of neonate will be just the continuation? This is still not easy question to answer, because even postnatally there are several neurological methods of evaluation, while in utero we are dealing with more complicated situation and less mature brain. Could neonatal assessment of neurologically impaired fetuses bring some new insights into their prenatal neurological status is still unclear and to be investigated. New scoring system for prenatal neurological assessment of the fetus proposed by Kurjak et al will give some new possibilities to detect fetuses at high neurological risk, although it is obvious that dynamic and complicated process of functional CNS development is not easy to investigate.

The aim of this review is to present continuity of the functional central nervous system assessment from prenatal to postnatal life.

How useful is 3D and 4D ultrasound in perinatal medicine?

AIM

The purpose of this paper is to review and analyze the published literature on the use of three-dimensional (3DUS) and four-dimensional (4DUS) ultrasound in perinatal medicine.

METHODS

We systematically searched Medline through PubMED (January 2000-January 2006), including EMBASE/Excerpta Medica database as well as the Cochrane Database of Systematic Reviews. The search terms used to identify clinical application of 3DUS and 4DUS studies in perinatal medicine were technical development, special features, and recommendation for fetal imaging, research on 3DUS or 4DUS, and the usage of invasive 3DUS or 4DUS procedures. The reference bibliographies of relevant books were also manually searched for supplementary citations. Inclusion criteria were as follows: (1) studies related to the use of 3DUS or 4DUS in perinatal medicine; (2) full text were available in English; (3) publication format of original scientific articles, case reports, editorials or literature reviews and chapters in the books.

RESULTS

Five hundred and seventy-five articles were identified, and among those, 438 were relevant to this review.

CONCLUSIONS

3DUS and 4DUS provided additional information for the diagnosis of facial anomalies, evaluation of neural tube defects, and skeletal malformations. Additional research is needed to determine the clinical utility of 3DUS and 4DUS for the diagnosis of congenital heart disease, central nervous system (CNS) anomalies and detection of fetal neurodevelopmental impairment assessed by abnormal behavior in high-risk fetuses.

Three and four-dimensional ultrasound in obstetrics and gynecology

PURPOSE OF REVIEW

Developments in ultrasound in general, but even more so in three-dimensional ultrasound, parallel the growth in computing power and speed of computer technology. It is not surprising, therefore, that three-dimensional ultrasound technology is constantly evolving at a fast pace. The purpose of this article is to provide enhanced diagnostic capabilities for the obstetrical and gynecologic provider.

RECENT FINDINGS

The most recent advances in three-dimensional ultrasound have to do with two main features. First, an increasingly fast acquisition speed, enabling quick sequences of fast moving organs such as the heart to be captured. Second, the increasing number of different display modalities, making understanding and analysis of normal anatomy and pathology easier for clinicians.

SUMMARY

This article highlights a selected number of clinical situations in which three-dimensional ultrasound meaningfully enhances the contribution of this fast evolving diagnostic imaging tool.

Neurosonography in the second half of fetal life: a neonatologist's point of view

This article reviews the interpretation of the fetal motor repertoire in the light of neurophysiology and clinical neurology. The continuity of the maturative process from the fetus to the neonate allows us to speculate on the predictive value of optimal and non-optimal neurological function as observed in the fetus and their morphological consequences. Neonatologists know that early prediction concerning outcome is reliable only at the two ends of the spectrum, e.g., optimal and very abnormal situations. However, in intermediate situations the quality of observations achieved by 3D-4D ultrasonography already allows to demonstrate the prenatal onset of brain damage, based on morphologic and functional signs. Their identification during the second half of pregnancy may serve as a retrospective marker of a prenatal insult.

The assessment of fetal behavior of growth restricted fetuses by 4D sonography

AIM

To find out whether the quantity of fetal facial expression and quality of body movements can be used as an additional diagnostic criterion for prenatal brain impairment in fetuses with growth restriction.

SUBJECT AND METHODS

A prospective study was conducted in 50 uncomplicated healthy women as control group with reliably dated pregnancies and 50 pregnant women with a growth restricted fetus as study group in the third trimester of pregnancy. 4D ultrasound observation is specially designed to assess whether functional brain impairment and fetal growth restriction had prenatally occurred by the utilization of several behavioral patterns.

RESULTS

The median value of all movement patterns in the normal fetuses differed from fetuses with intrauterine growth restriction (IUGR). Statistical evaluation revealed significant differences in the distribution of the movements between these groups (P<0.05). We noted a tendency that IUGR fetuses have less behavioral activity than normal fetuses in all observed movement patterns. Correlation reached statistical significance between normal and IUGR fetuses in the third trimester in hand to head, hand to face and head retroflexion. Statistically significant differences could be shown in the distribution of the median values of observation over the five qualitative categories of head and hand movements (P<0.05).

CONCLUSIONS

Recent data on IUGR fetuses obtained by 4D sonography are stimulating and might result in a more effective strategy to assess development before birth. The results of this study may encourage future use of 4D ultrasound for quantitative and qualitative assessment of fetal behavior as possible indicators of the neurological condition in IUGR fetuses.

Normal standards for fetal neurobehavioral developments--longitudinal quantification by four-dimensional sonography

AIM

To construct normal standards for fetal neurobehavioral development using longitudinal observations through all trimesters by four-dimensional sonography.

SUBJECT AND METHODS

A group of 100 healthy normal singleton pregnancies were recruited for longitudinal 4D US examinations to evaluate fetal neurodevelopmental parameters between 7 to 40 weeks' gestation. Variables of maternal and fetal characteristics including gestational age, eight fetal movements patterns in the first trimester and 14 parameters of fetal movement and fetal facial expression patterns recorded thereafter for the construction of fetal neurological charts.

RESULTS

Measurement of 7 parameters in the first trimester and 11 parameters in the second and third trimesters correlated with gestational age (P<0.05). Those parameters have been followed longitudinally through all trimesters and showed increasing frequency of fetal movements during the first trimester. A tendency towards decreased frequency of facial expressions and movement patterns with increasing gestational age from second to third trimesters has been noticed.

CONCLUSION

With 4D sonography, it is possible to quantitatively assess normal neurobehavioral development. There is urgent need for further multicentric studies until a sufficient degree of normative data is available and the predictive validity of the specific relationship between fetal neurobehavior and child developmental outcome is better established.

Three- and four-dimensional ultrasonography for the structural and functional evaluation of the fetal face

Ultrasonographic examination of the fetal face can provide information that may lead to the diagnosis of anomalies in other organs or systems. Thus, the fetal face represents a "diagnostic window" for fetal diseases and syndromes. Three-dimensional ultrasonography (3DUS) improves the evaluation of anatomic fetal facial anomalies over what is possible by 2-dimensional ultrasonography (2DUS). Four-dimensional ultrasonography (4DUS), by adding the temporal component to the examination, allows visualization of facial expressions that might be useful in the study of fetal behavior and maternal-fetal bonding. In this article, we evaluate the potential of 3D/4DUS for the study of structural and functional development of the fetal face.

Approach to the fetal movements: a pilot study of six cases

The aim of this study was to verify developmental aspects of fetal movements through 2D ultrasonic recordings of normal fetuses, product of low risk pregnancies. A qualitative analysis of the several types of movements was performed in a sample of six fetuses, each four weeks, from 12th to 40th gestational week. In the close period to 20th gestational week was registered the largest prevalence of movements. It was observed that certain movements disappear, and others stay or appear through period. Complex movements (breathing, deglutition and suction) were more frequent after the 20th week than before. In spite of the fetuses have presented a general motor pattern, individual variations were observed. These findings are in consonance with literature, toward the existence of certain motor patterns, with emergence and disappearance of the several types of movements according to the gestational age, and individual variations that suggest specificity.

Four-dimensional sonographic assessment of fetal facial expression early in the third trimester

OBJECTIVE

To evaluate the characteristic patterns of facial expression in fetuses aged from 28 to 34 weeks using 4-dimensional (4-D) ultrasonography.

METHODS

The faces of 10 healthy fetuses aged from 28 to 34 weeks were recorded continuously for 15 min with a 4-D ultrasonographic machine performing up to 25 frames per second. The occurrence rates of blinking, mouthing, yawning, tongue expulsion, smiling, scowling, and sucking were evaluated.

RESULTS

Mouthing was the most frequent facial expression (median, 6.5; range, 2-19) whereas the least frequent were scowling (median, 1; range, 0-9) and sucking (median, 1; range, 0-2). Mouthing was evident in all fetuses and significantly more frequent than any other movement (P<.05). Yawning (median, 3; range, 0-6), smiling (median, 2; range, 0-9), and blinking (median, 1.5; range, 0-6) were observed in most cases. Tongue expulsion (median, 1.5; range, 0-5), scowling, and sucking were each observed in 6 cases.

CONCLUSION

4-D sonography provides a means of evaluating fetal facial expression early in the third trimester. It may be a key to predicting fetal brain function and well-being and an important modality in future fetal neurophysiologic research.

The assessment of fetal behavior in early pregnancy: comparison between 2D and 4D sonographic scanning

AIM

To determine the accuracy of 4D sonography in the assessment of embryonic and early fetal motor activity in the first trimester of normal pregnancy, in comparison to the 2D sonography.

METHODS

Fifty pregnant women between 6-14 weeks of gestation with singleton pregnancy were assigned for the investigation. Two dimensional and four dimensional recordings were displayed on the screen and recorded on the videotape during the 15 minutes observation period.

RESULTS

General body, head and limb movements recorded by 2D sonography were notable by 4D technique in the same gestational age. These movements were presented collectively with maximum, minimum, and median frequencies during 15 minutes observation period. Spearman rank order correlation reached statistical significance (P<0.05) between the frequencies of all observed movement patterns assessed by two different techniques. Several movement patterns, such as sideway bending, hiccup, breathing movements, mouth opening and facial movements could be observed only by 2D sonographic technique in this period of gestation.

CONCLUSION

Presently, both 2D and 4D methods are required for the assessment of early fetal motor development and motor behavior. It is reasonable to expect that such technological improvement may provide some new information about the intrauterine motor activity and facilitate the prenatal detection of some neurological disorders.

Structural and functional early human development assessed by three-dimensional and four-dimensional sonography

OBJECTIVE

To summarize the role of three-dimensional and four-dimensional ultrasound in the assessment of early human development.

DESIGN

Review of literature.

SETTING

Ultrasound research center and obstetrics and gynecology department in a tertiary care facility.

RESULT(S)

The introduction of high-frequency transvaginal tranducers has resulted in remarkable progress in ultrasonographic visualization of early embryos and fetuses and the development of sonoembryology. Furthermore, recent introduction of three-dimensional and four-dimensional ultrasounds combined with the transvaginal approach has produced more objective and accurate information on embryonal and early fetal development. For the first time parallel analyses of structural and functional parameters in the first 12 weeks of gestation become possible.

CONCLUSION(S)

The anatomy and physiology of placental and embryonic development is a field where medicine exerts its greatest impact on early pregnancy at present time, and it opens fascinating aspects of embryonic differentiation. Clinical assessment of those stages of growth rely heavily on three-dimensional and four-dimensional sonography, one of the most promising forms of noninvasive diagnostics today and embryological phenomenon, once matters for textbooks are now routinely recorded with outstanding clarity.