Twins' temperament: early prenatal sonographic assessment and postnatal correlation

Fetal movements: A framework for antenatal conversations

BACKGROUND

Presentations for decreased fetal movements comprise a significant proportion of acute antenatal assessments. Decreased fetal movements are associated with increased likelihood of adverse pregnancy outcomes including stillbirth. Consensus-based guidelines recommend pregnant women routinely receive information about fetal movements, but practice is inconsistent, and the information shared is frequently not evidence-based. There are also knowledge gaps about the assessment and management of fetal movement concerns. Women have indicated that they would like more accurate information about what to expect regarding fetal movements.

DISCUSSION

Historically, fetal movement information has focussed on movement counts. This is problematic, as the number of fetal movements perceived varies widely between pregnant women, and no set number of movements has been established as a reliable indicator of fetal wellbeing. Of late, maternity care providers have also advised women to observe their baby's movement pattern, and promptly present if they notice a change. However, normal fetal movement patterns are rarely defined. Recently, a body of research has emerged relating to maternal perception of fetal movement features such as strength, presence of hiccups, and diurnal pattern as indicators of fetal wellbeing in addition to frequency.

CONCLUSION

Sharing comprehensive and gestation-appropriate information about fetal movements may be more satisfying for women, empowering women to identify for themselves when their baby is doing well, and importantly when additional assessment is needed. We propose a conversational approach to fetal movement information sharing, focusing on fetal movement strength, frequency, circadian pattern, and changes with normal fetal development, tailored to the individual.

Prenatal metal mixtures and sex-specific infant negative affectivity

Prenatal exposure to metals has been associated with a range of adverse neurocognitive outcomes; however, associations with early behavioral development are less well understood. We examined joint exposure to multiple co-occurring metals in relation to infant negative affect, a stable temperamental trait linked to psychopathology among children and adults.

METHODS

Analyses included 308 mother-infant pairs enrolled in the PRISM pregnancy cohort. We measured As, Ba, Cd, Cs, Cr, Pb, and Sb in urine, collected on average during late pregnancy, by ICP-MS. At age 6 months, we assessed negative affect using the Infant Behavior Questionnaire-Revised. We used Weighted Quantile Sum (WQS) regression with repeated holdout validation to estimate the joint association between the metals and global negative affectivity, as well as four subdomains (Fear, Sadness, Distress to Limitations, and Falling Reactivity). We also tested for a sex interaction with estimated stratified weights.

RESULTS

In adjusted models, urinary metals were associated with higher scores on the Fear scale (βWQS = 0.20, 95% confidence interval [CI]: 0.09, 0.30), which captures behavioral inhibition, characterized by startle or distress to sudden changes in the environment and inhibited approach to novelty. We observed a significant sex interaction (95% CI for the cross-product term: -0.19, -0.01), and stratified weights showed girls (61.6%) contributed substantially more to the mixture effect compared with boys (38.4%). Overall, Ba contributed the greatest mixture weight (22.5%), followed by Cs (14.9%) and As (14.6%).

CONCLUSIONS

Prenatal exposure to metals was associated with increased infant scores on the temperamental domain of fear, with girls showing particular sensitivity.Key words: Prenatal; Metals; Mixtures; Temperament; Infancy; Negative affect.

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.

Developmental trajectories of general and breathing movements in fetal twins

This study examined the developmental trajectories of general and breathing movements in fetal twins. Fetal movement patterns were assessed from real-time ultrasound recordings performed at 12-15, 20-23, and 28-32 weeks of gestation in 42 twin pairs. Results indicated that both general movements and breathing movements followed a curvilinear, inverted U-shaped curve. Developmental trajectories were unrelated within pairs of twins and were not associated with gestational age at birth and birth weight. However, sex differences were found for general movements with males displaying more time making general movements at 21 weeks and a steeper decline in time spent making general movements during the second half of pregnancy than females. These age-related changes in fetal movements may reflect CNS development. These findings also suggest that twins' behavioral development is largely independent of co-twin development, gestational age at birth, and birth weight, but not of fetal sex.

Predicting child temperament and behavior from the fetus

There remains little debate that the period before birth sets the stage for subsequent development, yet scant evidence exists showing continuity from characteristics of the individual fetus to characteristics of the child. This report examines, in two studies, whether baseline and evoked fetal neurobehavioral functioning are predictive of features of child temperament and behavior as reported by mothers when offspring were between 7 and 14 years old (M = 10.1 years). Study 1 utilizes data generated from 333 maternal-fetal pairs collected during an undisturbed condition during the second half of gestation in relation to the child temperament dimensions of behavioral inhibition and exuberance. Associations at 32 weeks gestation were detected between all features of fetal neurobehavior and behavioral inhibition. In adjusted models, slower fetal heart rate and less fetal movement were associated with significant unique variance in predicting higher levels of childhood behavioral inhibition. No associations were detected for exuberance. Study 2 focuses on the association of evoked fetal reactivity and recovery to induced maternal arousal with subsequent child behavioral difficulties in a subset of the full sample (n = 130). Greater recovery in fetal heart rate following maternal stimulation was predictive of fewer behavioral difficulties and more prosocial behavior in childhood. Results from both studies provide support for gestational origins of core individual differences that portend childhood outcomes with foundational reactivity and regulatory components.

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.

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.

STUDIES IN FETAL BEHAVIOR: REVISITED, RENEWED, AND REIMAGINED

Among the earliest volumes of this monograph series was a report by Lester Sontag and colleagues, of the esteemed Fels Institute, on the heart rate of the human fetus as an expression of the developing nervous system. Here, some 75 years later, we commemorate this work and provide historical and contemporary context on knowledge regarding fetal development, as well as results from our own research. These are based on synchronized monitoring of maternal and fetal parameters assessed between 24 and 36 weeks gestation on 740 maternal-fetal pairs compiled from eight separate longitudinal studies, which commenced in the early 1990s. Data include maternal heart rate, respiratory sinus arrhythmia, and electrodrmal activity and fetal heartrate, motor activity, and their integration. Hierarchical linear modeling of developmental trajectories reveals that the fetus develops in predictable ways consistent with advancing parasympathetic regulation. Findings also include:within-fetus stability (i.e., preservation of rank ordering over time) for heart rate, motor, and coupling measures; a transitional period of decelerating development near 30 weeks gestation; sex differences in fetal heart rate measures but not in most fetal motor activity measures; modest correspondence in fetal neurodevelopment among siblings as compared to unrelated fetuses; and deviations from normative fetal development in fetuses affected by intrauterine growth restriction and other conditions. Maternal parameters also change during this period of gestation and there is evidence that fetal sex and individual variation in fetal neurobehavior influence maternal physio-logical processes and the local intrauterine context. Results are discussed within the framework of neuromaturation, the emergence of individual differences, and the bidirectional nature of the maternal-fetal relationship.We pose a number of open questions for future research. Although the human fetus remains just out of reach, new technologies portend an era of accelerated discovery of the earliest period of development

Fetal heart rate and motor activity associations with maternal organochlorine levels: results of an exploratory study

Contemporaneous associations between circulating maternal organochlorines (OCs) and measures of fetal heart rate and motor activity were evaluated. A panel of 47 OCs, including pesticides and polychlorinated biphenyls (PCBs), was analyzed from serum of 50 pregnant women at 36 weeks gestation. Data were empirically reduced into four factors and six individual compounds. All participants had detectable concentrations of at least one-quarter of the assayed OCs and, in general, higher socioeconomic level was associated with higher OC concentrations. Fetal heart rate measures were not consistently associated with maternal OCs. In contrast, one or more indicators of greater fetal motor activity were significantly associated with higher levels of the DDT and low chlorinated OC factors and five of the six individual compounds (heptachlor epoxide, trans nonachlor, oxychlordane, and PCBs 18 and 52). This preliminary demonstration of associations between fetal motor activity and maternal concentrations of persistent and pervasive environmental contaminants suggests that fetal assessment may be useful in ascertaining the potential early effects of these compounds on development.

Fetal Behavior and Heart Rate in Twin Pregnancy: A Review

Fetal movements and fetal heart rate (FHR) are well-established markers of fetal well-being and maturation of the fetal central nervous system. The purpose of this paper is to review and discuss the available knowledge on fetal movements and heart rate patterns in twin pregnancies. There is some evidence for an association or similarity in fetal movement incidences or FHR patterns between both members of twin pairs. However, the temporal occurrence of these patterns seems to be for the most part asynchronous, especially when stricter criteria are used to define synchrony. The available data suggest that fetal behavior is largely independent of sex combination, fetal position, and presentation. Conversely, chorionicity appears to have some influence on fetal behavior, mainly before 30 weeks of gestation. There is preliminary evidence for the continuity of inter-individual differences in fetal activity and FHR patterns over pregnancy. Comparisons between studies are limited by large methodological differences and absence of uniform concepts and definitions. Future studies with high methodological quality are needed to provide a more comprehensive knowledge of normal fetal behavior in twin pregnancy.

Fetal behavior in normal dichorionic twin pregnancy

OBJECTIVES

A prospective study was performed to compare fetal behavioral development in healthy dichorionic twins and singletons, and identify twin intra-pair associations (synchrony) of fetal movements and rest-activity cycles using different criteria to define synchrony.

SUBJECTS AND METHODS

Twenty pregnant women carrying dichorionic twins participated. Serial simultaneous 1-hr recordings of fetal movements were made on twins between 11 and 40 weeks' gestation (wGA) using two ultrasound machines. All twins were born healthy after 36 wGA and of appropriate weight for gestation. The incidences of fetal generalized body movements (GM) and breathing movements in twins were compared with institutional reference values for singletons. A comprehensive smoothing procedure on the raw movement data was performed to evaluate previously reported variation in twin intra-pair synchrony.

RESULTS

Twin fetuses were less active (GM) than singletons throughout pregnancy, but their breathing activity was higher in the third trimester. The incidences of fetal GM, quiescence, and breathing were fairly correlated within twin pairs. However, the temporal association or simultaneous occurrence of these activities was poor, especially after 30 weeks' gestation, coinciding with emerging rest-activity cycles. There was no evidence of a consistently more active ('dominant') twin half. Potential confounders had no effect on behavioral development in fetal twins.

CONCLUSIONS

The results show differential behavioral development between normal dichorionic fetal twins and singletons. Within fetal twin-pairs, we found poor synchrony of movements and independent occurrence of rest-activity cycles. Previous research on fetal twin behavior appears to have overestimated the degree of intra-pair movement synchrony.

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.

Fetal reflex movement in twin pregnancies late in the first trimester: 4-D sonographic study

The objective of this study was to evaluate reactions to touch in utero between twin fetuses using 4-D sonography late in the first trimester of pregnancy. Six monochorionic diamniotic (MD) and eight dichorionic diamniotic (DD) pregnancies were studied for 30 min with transabdominal 4-D sonography at 12-13 weeks' gestation. The frequencies of no reaction (twins appear to touch each other but there is no clear reaction) and reaction (twins appear to touch each other and there is a clear reaction by the co-twin) movements were evaluated. There was no significant difference in the rate of reaction movements between MD (median, 33.6%) and DD (median, 33.9%) twins. The median rate of reaction movements in all 14 twins was 33.9% (range, 27 to 64.1%). Our findings suggest that the incidence of reflex movement of the co-twin on being touched by the other twin late in the first trimester is more frequent than that assessed by conventional 2-D ultrasound.

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.