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

Made to move: A review of measurement strategies to characterize heterogeneity in normal fetal movement

Fetal movement is a crucial indicator of fetal well-being. Characteristics of fetal movement vary across gestation, posing challenges for researchers to determine the most suitable assessment of fetal movement for their study. We summarize the current measurement strategies used to assess fetal movement and conduct a comprehensive review of studies utilizing these methods. We critically evaluate various measurement approaches including subjective maternal perception, ultrasound, Doppler ultrasound, wearable technology, magnetocardiograms, and magnetic resonance imaging, highlighting their strengths and weaknesses. We discuss the challenges of accurately capturing fetal movement, which is influenced by factors such as differences in recording times, gestational ages, sample sizes, environmental conditions, subjective perceptions, and characterization across studies. We also highlight the clinical implications of heterogeneity in fetal movement assessment for monitoring fetal behavior, predicting adverse outcomes, and improving maternal attachment to the fetus. Lastly, we propose potential areas of future research to overcome the current gaps and challenges in measuring and characterizing abnormal fetal movement. Our review contributes to the growing body of literature on fetal movement assessment and provides insights into the methodological considerations and potential applications for research.

Species-specific Posture of Human Foetus in Late First Trimester

The ontogeny associated with the arm-hanging posture, which is considered ape-specific, remains unknown. To examine its ontogeny, we measured foetal movements of 62 human foetuses aged 10-20 gestation weeks using four-dimensional sonography. We observed that the first-trimester foetuses show this particular species-specific posture. After 11 weeks of gestation, all foetuses showed the arm-hanging posture, and the posture was most frequently observed at 14-16 weeks of gestation. Moreover, this posture often involved extension of both arms and both legs, indicating that it is not myogenic but neurogenic. Furthermore, early ontogeny suggests that it originates because of subcortical activity. Such posture extension bias and persistence indicates that vestibulospinal tract maturation involves the ontogeny of arm-hanging posture during 14-16 weeks of gestation.

Visualization and quantitation of fetal movements by real-time three-dimensional ultrasound with live xPlane imaging in the first trimester of pregnancy

Aim

To prove whether real-time three-dimensional (3D) ultrasound with live xPlane imaging is better in observing fetal movements than standard ultrasound imaging.

Methods

50 healthy women with singleton pregnancies (22-43 years old) at 11 to 14 weeks of gestation underwent real-time 3D ultrasound examination with live xPlane imaging from July 2014 to February 2015. The incidence and frequency of 10 fetal movement patterns in 10 minutes were evaluated, including general movements (GMs), isolated arm movements, isolated leg movements, hiccup, stretching, breathing, startle, jaw opening, isolated head retroflexion, and isolated head anteflexion. The correlation between gestational age and frequency of each fetal movement pattern was analyzed.

Results

GM had the highest incidence (100%), followed by startle (84%) and isolated arm movements (68%). Their median frequency was 5 (IQR 3-6), 5 (IQR 1.75-11.5), and 1 (IQR 0-2), respectively. GM (Z = 5.875, P < 0.001) and startle (Z = 5.302, P < 0.001) had significantly higher frequency than isolated arm movements. The other 7 fetal movement patterns had much lower incidence and frequency. The frequency of GM was positively correlated with gestational age (r = 0.360, P = 0.010).

Conclusion

Real-time 3D ultrasound with live x Plane imaging was shown to be a feasible tool for observing fetal movements.

Fetal Neurology: The Role of Fetal Stress

Fetal development and growth, as well as the timing of birth is influenced by the intrauterine environment. Many environmental factors causing the fetal stress can interfere with fetal development and leave long-term and profound consequences on health. Fetal glucocorticoid overexposure has primarily significant consequences for the development of the central nervous system. In response to an adverse intrauterine conditions, the fetus is able to adapt its physiology to promote survival. However, these adaptations can result in permanent changes in tissue and organ structure and function that directly ‘program’ predisposition to disease. Cardiometabolic disorders, behavioral alterations and neuropsychiatric impairments in adulthood and/ or childhood may have their roots in the fetal period of life. Fetal response to stress and its prenatal and lifelong consequences are discussed in this review.

How to cite this article

Kadić AS. Fetal Neurology: The Role of Fetal Stress. Donald School J Ultrasound Obstet Gynecol 2015;9(1):30-39.

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 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.

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.

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.

Fetal neurophysiology according to gestational age

More than 99% of the human neocortex is fashioned during intrauterine life, resulting in the fascinating diversity of fetal functions and activities. The objective of this review is to present the most significant neurodevelopmental events, as well as new findings about prenatal motor and sensory development.

Fetal habituation in assisted conception

BACKGROUND

Neurodevelopment outcomes of children conceived by Assisted Reproductive Technology (ART)have been the subject of much recent attention. To date there are no reports of neurodevelopmental performance before birth in this group.

AIMS

To compare habituation (a measure of brain function) in fetuses conceived by assisted reproduction techniques (ART) with naturally conceived (NC) fetuses.

STUDY DESIGN

Case control study.

SUBJECTS

Women with singleton pregnancies matched for maternal age, parity and smoking were recruited in 2 groups: ART (n=20) and NC (n=20).

OUTCOME MEASURES

Sound stimuli (250 Hz, 110 dB) at 10 second intervals lasting 2 s were administered to the fetus. The end point was habituation (cessation of movement for five consecutive stimuli) or a maximum of 30 stimuli. Responses of the fetus were observed with ultrasound at 28, 32 and 36 weeks' gestation, video-recorded and anonymised for analysis.

RESULTS

At 28 weeks' gestation significantly more ART fetuses responded to sound of 250 Hz, 110 dB (p=0.02) but this difference did not persist at 32 and 36 weeks'. There was a significant increase in nonresponders as gestation advanced in the ART group. There was no difference in habituation or mean number of trials to habituate at all three gestations.

CONCLUSIONS

ART fetuses demonstrated no differences in habituation suggesting that there is no neurodevelopment delay. However, a decrease in response to sound as gestation advances might be a harbinger for poor perinatal outcomes and needs exploration.

What We have Learned from Fetal Neurophysiology?

The nervous system is one of the earliest emerging systems in fetal development. Due to progress of modern imaging technologies, such as ultrasound, a growing pool of information on the development of the central nervous system (CNS) and fetal behavioral patterns has been made available. The major events in the development of the CNS, fetal motor and sensory development as well as fetal response to stress are discussed in this review. The fetus is not entirely protected from harmful influence of the external factors. Postnatal follow-up studies have showed that many environmental influences causing the fetal stress can interfere with the fetal neurodevelopment and leave long-term and profound consequences on brain structure and function.

How to cite this article

SalihagićKadić A, Predojevic M. What We have Learned from Fetal Neurophysiology? Donald School J Ultrasound Obstet Gynecol 2012;6(2):179-188.

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.

Mother's anxiety and depression and associated risk factors during early pregnancy: effects on fetal growth and activity at 20-22 weeks of gestation

To examine effects of mother's anxiety and depression and associated risk factors during early pregnancy on fetal growth and activity. Repeated measures of mother's anxiety (State-Anxiety Inventory (STAI-S)) and depression (Edinburgh Postnatal Depression Scale (EPDS)) and related socio demographics and substance consumption were obtained at the 1st and 2nd pregnancy trimesters, and fetus' (N = 147) biometric data and behavior was recorded during ultrasound examination at 20-22 weeks of gestation. Higher anxiety symptoms were associated to both lower fetal growth and higher fetal activity. While lower education, primiparity, adolescent motherhood, and tobacco consumption predicted lower fetal growth, coffee intake predicted lower fetal activity. Vulnerability of fetal development to mother's psychological symptoms as well as to other sociodemographic and substance consumption risk factors during early and mid pregnancy is suggested.

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.

Twins' temperament: early prenatal sonographic assessment and postnatal correlation

OBJECTIVE

To study inter-twin differences in activity during early pregnancy and to examine their relationship to subsequent infant twins' temperament.

STUDY DESIGN

Measures of fetal motor activity (frequency, duration and number of movements) were collected from 26 twin pairs during ultrasound nuchal translucency scan at late first trimester and early second trimester (11 to 14 weeks gestation). In twenty-two patients, the twins were dizygotic (dichorionic); of them, 13 twin pairs were of different sexes, five were both females and four were both males. Of the four monozygotic twin pregnancies, two were dichorionic and two were monochorionic, three were both females.The more active fetus in each pair was noted according to the position and/or sex without reporting to parents. Reported maternal perception of the more active twin was documented at the mid-trimester anatomical scan. Maternally reported postnatal temperament data of the infants were collected at 3 and 6 months, using Rothbarts' Infant Behavior Questionnaire (IBQ).

RESULTS

After birth, maternal reports on infants' temperament and the more active twin in each pair were in good correlation with prenatal inter-twin differences in activity. The receiver operating characteristic (ROC) curves shows a better performance of ultrasound compared with maternal perception in prediction of the more active twin.

CONCLUSIONS

The features of fetal neurobehavioral activity provide the basis for individual differences in twins' activity in infancy. Differences in activity in early pregnancy even before the emergence of fetal behavioral patterns were followed by temperamental differences postnatally.

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.

Magnetographic assessment of fetal hiccups and their effect on fetal heart rhythm

Fetal hiccups emerge as early as nine weeks post-conception, being the predominant diaphragmatic movement before 26 weeks of gestation. They are considered as a programmed isometric inspiratory muscle exercise of the fetus in preparation for the post-natal respiratory function, or a manifestation of a reflex circuitry underlying the development of suckling and gasping patterns. The present paper provides the first evidence of non-invasive biomagnetic measurements of the diaphragm spasmodic contractions associated with fetal hiccups. The magnetic field patterns generated by fetal hiccups exhibit well-defined morphological features, consisting of an initial high frequency transient waveform followed by a more prolonged low frequency component. This pattern is consistent across recordings obtained from two fetal subjects, and it is confirmed by signals recorded in a neonatal subject. These results demonstrate that fetal biomagnetometry can provide insights into the electrophysiological mechanisms of diaphragm motor function in the fetus. Additionally, we study the correlation between hiccup events and fetal cardiac rhythm and provide evidence that hiccups may modulate the fetal heart rate during the last trimester of pregnancy.

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.

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 of fetal behavior assessed by four-dimensional sonography

OBJECTIVE

In this prospective randomized study, fetal behavior was investigated in order to determine the standard parameters of fetal movements and facial expressions in all three trimesters of normal pregnancy.

METHODS

Sixty-three pregnant women with singleton pregnancies in all trimesters were included in the investigation. Four-dimensional (4D) ultrasound was performed for each patient over a 30-minute period. Variables of maternal and fetal characteristics including gestational age, eight fetal movement patterns in the first trimester, and sixteen parameters of fetal movement and fetal facial expression patterns in the second and third trimesters were recorded for the construction of fetal neurological charts.

RESULTS

In the first trimester, a tendency towards an increased frequency of fetal movement patterns with increasing gestational age was noticed. Only the startle movement pattern seemed to occur stagnantly during the first trimester (p > 0.05). At the beginning of the second trimester, the frequency of fetal movement patterns tended to increase. During the second and third trimester, multiple regression and polynomial regression revealed statistically significant changes in tongue expulsion (p < 0.05), smiling (p < 0.05), grimacing (p < 0.05), swallowing (p < 0.05), eye blinking (p < 0.01), head movements, and all hand to body contact movements (p < 0.01), except for head anteflexion (p > 0.05). There were no statistically significant changes during the second and third trimesters in mouthing, yawning, and sucking (p > 0.05). At the middle of the third trimester, the fetuses displayed decreasing or stagnant incidence of fetal facial expressions except for eye blinking, which showed increased frequency with increasing gestational age. A statistically significant correlation was found between all head movements and hand to body contact patterns during the second and third trimesters except for head anteflexion (r = -0.231; p > 0.05).

CONCLUSIONS

The full range of quantitative fetal facial expressions and fetal movement patterns can be assessed successfully by 4D sonography. It is important to be able to assess normal fetal behavior throughout gestation to identify abnormal behavior before birth.

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.

New data about embryonic and fetal neurodevelopment and behavior obtained by 3D and 4D sonography

The development of the human central nervous system (CNS) begins in the early embryonic period and proceeds through a sequence of very complicated processes long after delivery. Although the neurodevelopmental processes are genetically determined, their complexity and intensity implicates the vulnerability of the CNS to number of environmental factors. There is substantial evidence to show that many neurological problems, from minor cerebral dysfunction to the cerebral palsy, originate form the prenatal, rather than perinatal or postnatal periods of life. A variety of neurological and neuropsychiatric diseases is nowadays considered to originate, at least partly, from the prenatal incidents. In most of these conditions, there is no reliable parameter for detection or prediction of cerebral lesions and there is an urgent need to develop strategies that would enable the early detection of cerebral lesions or indications that such lesions might occur. The new, advanced, imaging techniques such as 3-dimensional and 4-dimensional sonography, opened a new perspective for the investigation of structural and functional development of fetal CNS. The application of these techniques might improve our understanding of the prenatal neurodevelopmental events and possibly facilitate the development of diagnostic strategies for early detection or prevention of brain dysfunctions and damage.