4D ultrasound evaluation of fetal facial expressions during the latter stages of the second trimester

Frontal tangential coronal view two-dimensional ultrasonography in assessment of fetal face [mouth and nose] in comparison with four-dimensional ultrasonography

Background

The fetal face reflects strictly the development of the fetal brain during its growth. Four-dimensional (4D) examination permits continuous monitoring of the examined parts of fetal face and surface. The final performance of obstetric sonographic images depends upon multiple factors, such as fetal lie, uterine wall, abdominal wall fat, amniotic fluid, and the number of gestations which may limit the optimum performance of (4D) ultrasound. The two-dimensional (2D) ultrasound is the first choice due to its wide availability, low cost, and real-time capabilities. The tangential view obtained by (2D) ultrasound coronal sections through the face showed the nose, nostril, lips, eye, lens, and hard palate.

Results

One hundred and sixty fetuses showed straight forwards obstetric examination by both 2D and 4D examinations with identical final reports. While the total number of fetuses with clear images by 2D frontal tangential coronal examination was 191 cases, only 29 cases failed, whereas 170 cases obtained clear images by 4D examination, and 50 cases failed. Both 2D and 4D ultrasound failed to obtain clear images of 19 cases, while 4D failed for 31 cases, and 2D failed for 10 cases. 2D imaging was found to be significantly better than 4D imaging, with a P value of 0.009.

Conclusion

2D ultrasound using the frontal tangential coronal view is an essential part of the fetal examination and more superior than 4D ultrasound in assessing facial anatomy and anomalies, as well comparable to 4D ultrasound as regards fascial expression.

A new approach for quantitative assessment of fetal general movements in the early second trimester of pregnancy using four-dimensional ultrasound

PURPOSE

Complex fetal behavior involving multiple parts of the body, called general movement (GM), has been considered an essential predictor of neurological functional development because it directly reflects the integrity of the brain and central and peripheral nervous systems. We have developed a novel method for quantitative analysis of fetal behavior using four-dimensional ultrasound (4DUS) and conducted a pilot study for quantitative assessment of fetal GM in the early second trimester.

METHODS

All subjects underwent 4DUS to depict the whole fetal body, and maximum velocity (MAXV), median velocity (MV), average velocity (AV), and mode velocity (MOV) were calculated by utilizing optical flow analysis. Receiver operating characteristic (ROC) curve analysis was performed to analyze the optimal speed parameters for detecting GM in the fetus. The Mann-Whitney U test was used to validate MAXV, AV, and MV ability to detect fetal GM.

RESULTS

The presence of fetal GMs and the absence of fetal GMs were 226 and 107, respectively, based on optical flow analysis. Mann-Whitney U test revealed a significant difference in the presence or absence of fetal GM in MAXV, MV, AV, and MOV. ROC analysis showed that the area under the curve (AUC) of MAXV was 0.959; the threshold was 0.421, the sensitivity was 86%, and the specificity was 93%. In contrast, the AUC/threshold for AV and MV was 0.700/0.110 (sensitivity 71% and specificity 76%) and 0.521/0.119 (sensitivity 21% and specificity 90%), respectively. Spearman's rank correlation analysis also showed a weak negative correlation between GM and MAXV (r = - 0.235, P < 0.01) and AV (r = - 0.28, P < 0.01).

CONCLUSION

In this study, we conducted a quantitative analysis of fetal behavior based on optical flow using 4DUS and demonstrated that it was highly accurate for detecting GMs and for evaluating developmental changes in GMs. The implementation of quantitative analysis of fetal GMs in the early second trimester has been very preliminary, and there is much debate on how it will be clinically applied to perinatal assessment.

Identifying fetal yawns based on temporal dynamics of mouth openings: A preterm neonate model using support vector machines (SVMs)

Fetal yawning is of interest because of its clinical, developmental and theoretical implications. However, the methodological challenges of identifying yawns from ultrasonographic scans have not been systematically addressed. We report two studies that examined the temporal dynamics of yawning in preterm neonates comparable in developmental level to fetuses observed in ultrasound studies (about 31 weeks PMA). In Study 1 we tested the reliability and construct validity of the only quantitative measure for identifying fetal yawns in the literature, by comparing its scores with a more detailed behavioral coding system (The System for Coding Perinatal Behavior, SCPB) adapted from the comprehensive, anatomically based Facial Action Coding System for Infants and Young Children (Baby FACS). The previously published measure yielded good reliability but poor specificity, resulting in over-representation of yawns. In Study 2 we developed and tested a new machine learning system based on support vector machines (SVM) for identifying yawns. The system displayed excellent specificity and sensitivity, proving it to be a reliable and valid tool for identifying yawns in fetuses and neonates. This achievement represents a first step towards a fully automated system for identifying yawns in the perinatal period.

Twin fetal facial expressions at 30-33+6 weeks of gestation

Objective To assess the characteristics of twin fetal facial expressions at 30-33 + 6 weeks of gestation using four-dimensional (4D) ultrasound to clarify twin fetal brain development and maturation. Methods Frequencies of seven fetal facial expressions were studied using 4D ultrasound for 15 minutes in 30 singleton pregnancies and 18 twin pregnancies [four monochorionic diamniotic (MD) and 14 dichorionic diamniotic (DD) twins] at 30-33 + 6 weeks of gestation. Comparison of the frequency in each facial expression was performed between singleton and twin fetuses. Results Mouthing was the most frequent facial expression at 30-33 + 6 weeks of gestation, followed by blinking in twin and singleton fetuses. Both facial expressions were significantly more frequent than other expressions (P < 0.05). The frequencies of mouthing and scowling in twin fetuses were significantly lower than those in singleton fetuses, but there were no significant differences in the frequencies of the five other facial expressions between the fetal groups. Conclusion Our results suggest that restricted twin fetal behavior before 20 weeks of gestation may still affect the frequencies of twin facial expressions early in the third trimester of pregnancy. Moreover, the frequencies of facial expressions in twins are different from those of singleton fetuses.

Multi-center results on the clinical use of KANET

An extensive review of the literature on the diagnostic and clinical accuracy of Kurjak's antenatal neurodevelopmental test (KANET) and the summarized results of the multi-center study involving 10 centers revealed that four-dimensional ultrasonography (4D US) has become a powerful tool and KANET a valuable test that empowers the clinicians worldwide to evaluate the fetal behavior in a systematic way and contribute to the detection of fetuses that might be at high risk for neurological impairments and in particular cerebral palsy (CP). After 10 years of clinical use, many published papers and multi-center studies, hundreds of trained physicians and numerous tests performed all over the world, KANET has proven its value and has been showing encouraging results so far. The aim of this paper is to show the results from the studies done so far and to reveal the clinical value of the KANET. We expect that data from the larger ongoing collaborative study, the short- and long-term postnatal follow-up will continue to improve our knowledge. Ultimately, we all strive to prevent the CP disorders, autism spectrum disorder (ASD) and other neurological impairments and we are convinced that KANET might be helpful in the realization of this important aim.

Beyond neonatal imitation: Aerodigestive stereotypies, speech development, and social interaction in the extended perinatal period

In our target article, we argued that the positive results of neonatal imitation are likely to be by-products of normal aerodigestive development. Our hypothesis elicited various responses on the role of social interaction in infancy, the methodological issues about imitation experiments, and the relation between the aerodigestive theory and the development of speech. Here we respond to the commentaries.

Neurological development may be accelerated in growth-restricted fetuses: a 4D ultrasound study

Objective To assess whether neurological maturation and development are accelerated in fetal growth restriction (FGR) in utero using four-dimensional (4D) ultrasound. Methods The facial expressions of 50 appropriate-for-gestational-age (AGA) and 34 FGR fetuses aged between 28 and 35 gestational weeks were assessed using 4D ultrasound. Subsequently, they were differentiated into two gestational age groups (19 aged 28-31 weeks and 31 aged 32-35 weeks in AGA, and 15 aged 28-31 weeks and 19 aged 32-35 weeks in FGR). Fifteen-minute recordings were made, and the frequencies of seven facial expressions during that time were examined. Correlation analysis was conducted to assess the changing number of significant correlations with advancing gestation in each group. Results Out of 21 combinations of facial expressions at 28-31 and 32-35 gestational weeks in AGA fetuses, there was only three significant correlations. Similarly, only one was noted out of 21 combinations at 28-31 gestational weeks, but there were seven significant correlations in FGR fetuses at 32-35 weeks (P=0.018). However, there was no significant difference in the number of correlations of facial expressions between AGA (3/21) and FGR (7/21) fetuses at 32-35 weeks of gestation (P=0.147). Conclusion Our results suggest that the number of significant correlations of fetal facial expressions in FGR fetuses increases more compared with that in AGA fetuses at 32-35 weeks of gestation. Due to the acceleration of neurological maturation and development in FGR fetuses, the control of facial expressions by the brain may be more evident compared with AGA fetuses at 32-35 weeks of gestation. 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 obtain strong or additional evidence.

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.

Fetal face as important indicator of fetal brain function

Fetuses show various facial expressions, such as blinking, yawning, sucking, mouthing, tongue expulsion, scowling, and smiling, assessed by four-dimensional ultrasound from the early second trimester of pregnancy. Moreover, some fetuses demonstrate emotion-like behaviors as noted in infants, children, and adults. Selective fetal responses to stimuli indicate a high degree of brain development, which is reflected in the facial reactions. The fetal face with its movements and expressions can mirror the fetal brain function and development during different stages of the fetus in utero. The fetal face might represent the key to opening the box containing the secrets of fetal brain function and development. Four-dimensional ultrasound may be an important modality in current and future research on fetal facial expressions and assist in the evaluation of the fetal brain function.

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.

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.

Fetal facial expression in response to intravaginal music emission

This study compared fetal response to musical stimuli applied intravaginally (intravaginal music [IVM]) with application via emitters placed on the mother’s abdomen (abdominal music [ABM]). Responses were quantified by recording facial movements identified on 3D/4D ultrasound. One hundred and six normal pregnancies between 14 and 39 weeks of gestation were randomized to 3D/4D ultrasound with: (a) ABM with standard headphones (flute monody at 98.6 dB); (b) IVM with a specially designed device emitting the same monody at 53.7 dB; or (c) intravaginal vibration (IVV; 125 Hz) at 68 dB with the same device. Facial movements were quantified at baseline, during stimulation, and for 5 minutes after stimulation was discontinued. In fetuses at a gestational age of >16 weeks, IVM-elicited mouthing (MT) and tongue expulsion (TE) in 86.7% and 46.6% of fetuses, respectively, with significant differences when compared with ABM and IVV (p = 0.002 and p = 0.004, respectively). There were no changes from baseline in ABM and IVV. TE occurred ≥5 times in 5 minutes in 13.3% with IVM. IVM was related with higher occurrence of MT (odds ratio = 10.980; 95% confidence interval = 3.105–47.546) and TE (odds ratio = 10.943; 95% confidence interval = 2.568–77.037). The frequency of TE with IVM increased significantly with gestational age (p = 0.024). Fetuses at 16–39 weeks of gestation respond to intravaginally emitted music with repetitive MT and TE movements not observed with ABM or IVV. Our findings suggest that neural pathways participating in the auditory–motor system are developed as early as gestational week 16. These findings might contribute to diagnostic methods for prenatal hearing screening, and research into fetal neurological stimulation.

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.

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.

4D ultrasound study of fetal facial expressions at 20-24 weeks of gestation

OBJECTIVE

To assess the frequency of fetal facial expressions at 20-24 weeks of gestation using four-dimensional (4D) ultrasonography and to determine whether there was any correlation between facial expression and gestational age (20-34 weeks).

METHODS

The facial expressions of 23 healthy fetuses were examined using 4D ultrasound at 20-24 weeks. Each fetus was recorded continuously for 15 minutes. The frequencies of mouthing, yawning, smiling, tongue expulsion, scowling, sucking, and blinking were assessed and the data combined with those expressions observed at 25-34 weeks of gestation in two previous studies (n = 34) to determine the correlation between gestational age and each of the facial expressions.

RESULTS

Mouthing was significantly more frequent than the other six facial expressions at 20-24 weeks (P < 0.05). Yawning was significantly more frequent than smiling, scowling, and blinking (P < 0.05), and sucking was significantly more frequent than smiling, scowling, and blinking (P < 0.05). The frequency of yawning, smiling, tongue expulsion, scowling, and blinking increased with gestational age (P < 0.05). Mouthing movement and sucking frequencies remained constant between 20 and 34 weeks.

CONCLUSION

Frequencies of complicated facial expressions such as smiling and scowling may increase with advancing gestation owing to the development of the fetal brain and central nervous system.