Fetal responsiveness to maternal passive swinging in low heart rate variability state: effects of stimulation direction and duration

Towards a neurodevelopmental cognitive perspective of temporal processing

The ability to organize and memorize the unfolding of events over time is a fundamental feature of cognition, which develops concurrently with the maturation of the brain. Nonetheless, how temporal processing evolves across the lifetime as well as the links with the underlying neural substrates remains unclear. Here, we intend to retrace the main developmental stages of brain structure, function, and cognition linked to the emergence of timing abilities. This neurodevelopmental perspective aims to untangle the puzzling trajectory of temporal processing aspects across the lifetime, paving the way to novel neuropsychological assessments and cognitive rehabilitation strategies.

The key to understanding core knowledge resides in the fetus

What Babies Know outlines a compelling case for why infancy research is fundamental for conceptualizing what it is to be human. There is another period in human development that is relatively inaccessible, yet is more important. In order to truly understand the nature of core knowledge, perception, and cognition, we must start not with the infant, but with the fetus.

Evidence for Top-down Meter Perception in Infancy as Shown by Primed Neural Responses to an Ambiguous Rhythm

From auditory rhythm patterns, listeners extract the underlying steady beat, and perceptually group beats to form meters. While previous studies show infants discriminate different auditory meters, it remains unknown whether they can maintain (imagine) a metrical interpretation of an ambiguous rhythm through top-down processes. We investigated this via electroencephalographic mismatch responses. We primed 6-month-old infants (N = 24) to hear a 6-beat ambiguous rhythm either in duple meter (n = 13), or in triple meter (n = 11) through loudness accents either on every second or every third beat. Periods of priming were inserted before sequences of the ambiguous unaccented rhythm. To elicit mismatch responses, occasional pitch deviants occurred on either beat 4 (strong beat in triple meter; weak in duple) or beat 5 (strong in duple; weak in triple) of the unaccented trials. At frontal left sites, we found a significant interaction between beat and priming group in the predicted direction. Post-hoc analyses showed mismatch response amplitudes were significantly larger for beat 5 in the duple- than triple-primed group (p = .047) and were non-significantly larger for beat 4 in the triple- than duple-primed group. Further, amplitudes were generally larger in infants with musically experienced parents. At frontal right sites, mismatch responses were generally larger for those in the duple compared to triple group, which may reflect a processing advantage for duple meter. These results indicate infants can impose a top-down, internally generated meter on ambiguous auditory rhythms, an ability that would aid early language and music learning.

The Importance of Rhythmic Stimulation for Preterm Infants in the NICU

The fetal environment provides the fetus with multiple potential sources of rhythmic stimulation that are not present in the NICU. Maternal breathing, heartbeats, walking, dancing, running, speaking, singing, etc., all bathe the fetus in an environment of varied rhythmic stimuli: vestibular, somatosensory, tactile, and auditory. In contrast, the NICU environment does not offer the same proportion of rhythmic stimulation. After analyzing the lack of rhythmic stimulation in the NICU, this review highlights the different proposals for vestibular and/or auditory rhythmic stimulation offered to preterm infants alone and with their parents. The focus is on the beneficial effects of auditory and vestibular stimulation involving both partners of the mother-infant dyad. A preliminary study on the influence of a skin-to-skin lullaby on the stability of maternal behavior and on the tonic emotional manifestations of the preterm infant is presented as an example. The review concludes with the importance of introducing rhythmic stimulations in the NICU.

Preparing for Life After Birth: Introducing the Concepts of Intrauterine and Extrauterine Sensory Entrainment in Mammalian Young

Presented is an updated understanding of the development of sensory systems in the offspring of a wide range of terrestrial mammals, the prenatal exposure of those systems to salient stimuli, and the mechanisms by which that exposure can embed particular sensory capabilities that prepare newborns to respond appropriately to similar stimuli they may encounter after birth. Taken together, these are the constituents of the phenomenon of "trans-natal sensory continuity" where the embedded sensory capabilities are considered to have been "learnt" and, when accessed subsequently, they are said to have been "remembered". An alternative explanation of trans-natal sensory continuity is provided here in order to focus on the mechanisms of "embedding" and "accessing" instead of the potentially more subjectively conceived outcomes of "learning" and "memory". Thus, the mechanistic concept of "intrauterine sensory entrainment" has been introduced, its foundation being the well-established neuroplastic capability of nervous systems to respond to sensory inputs by reorganising their neural structures, functions, and connections. Five conditions need to be met before "trans-natal sensory continuity" can occur. They are (1) sufficient neurological maturity to support minimal functional activity in specific sensory receptor systems in utero; (2) the presence of sensory stimuli that activate their aligned receptors before birth; (3) the neurological capability for entrained functions within specific sensory modalities to be retained beyond birth; (4) specific sensory stimuli that are effective both before and after birth; and (5) a capability to detect those stimuli when or if they are presented after birth in ways that differ (e.g., in air) from their presentation via fluid media before birth. Numerous beneficial outcomes of this process have been reported for mammalian newborns, but the range of benefits depends on how many of the full set of sensory modalities are functional at the time of birth. Thus, the breadth of sensory capabilities may be extensive, somewhat restricted, or minimal in offspring that are, respectively, neurologically mature, moderately immature, or exceptionally immature at birth. It is noted that birth marks a transition from intrauterine sensory entrainment to extrauterine sensory entrainment in all mammalian young. Depending on their neurological maturity, extrauterine entrainment contributes to the continuing maturation of the different sensory systems that are operational at birth, the later development and maturation of the systems that are absent at birth, and the combined impact of those factors on the behaviour of newborn and young mammals. Intrauterine sensory entrainment helps to prepare mammalian young for life immediately after birth, and extrauterine sensory entrainment continues this process until all sensory modalities develop full functionality. It is apparent that, overall, extrauterine sensory entrainment and its aligned neuroplastic responses underlie numerous postnatal learning and memory events which contribute to the maturation of all sensory capabilities that eventually enable mammalian young to live autonomously.

Transfer entropy analysis of maternal and fetal heart rate coupling

Although evidence of the short term relationship between maternal and fetal heart rates has been found in previous model-based studies, knowledge about the mechanism and patterns of the coupling during gestation is still limited. In this study, a model-free method based on Transfer Entropy (TE) was applied to quantify the maternal-fetal heart rate couplings in both directions. Furthermore, analysis of the lag at which TE was maximum and its changes throughout gestation, provided more information about the mechanism of coupling and its latency. Experimental results based on fetal electrocardiograms (fECGs) and maternal ECG showed the evidence of coupling for 62 out of 65 healthy mothers and fetuses in each direction, by statistically validating against the surrogate pairs. The fetuses were divided into three gestational age groups: early (16-25 weeks), mid (26-31 weeks) and late (32-41 weeks) gestation. The maximum TE from maternal to fetal heart rate significantly increased from early to mid gestation, while the coupling delay on both directions decreased significantly from mid to late gestation. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. In conclusion, the application of TE with delays revealed detailed information about the changes in fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being.

Quantifying the Interactions between Maternal and Fetal Heart Rates by Transfer Entropy

Evidence of the short term relationship between maternal and fetal heart rates has been found in previous studies. However there is still limited knowledge about underlying mechanisms and patterns of the coupling throughout gestation. In this study, Transfer Entropy (TE) was used to quantify directed interactions between maternal and fetal heart rates at various time delays and gestational ages. Experimental results using maternal and fetal electrocardiograms showed significant coupling for 63 out of 65 fetuses, by statistically validating against surrogate pairs. Analysis of TE showed a decrease in transfer of information from fetus to the mother with gestational age, alongside the maturation of the fetus. On the other hand, maternal to fetal TE was significantly greater in mid (26-31 weeks) and late (32-41 weeks) gestation compared to early (16-25 weeks) gestation (Mann Whitney Wilcoxon (MWW) p<0.05). TE further increased from mid to late, for the fetuses with RMSSD of fetal heart rate being larger than 4 msec in the late gestation. This difference was not observed for the fetuses with smaller RMSSD, which could be associated with the quiet sleep state. Delay in the information transfer from mother to fetus significantly decreased (p = 0.03) from mid to late gestation, implying a decrease in fetal response time. These changes occur concomitant with the maturation of the fetal sensory and autonomic nervous systems with advancing gestational age. The effect of maternal respiratory rate derived from maternal ECG was also investigated and no significant relationship was found between breathing rate and TE at any lag. In conclusion, the application of TE with delays revealed detailed information on the fetal-maternal heart rate coupling strength and latency throughout gestation, which could provide novel clinical markers of fetal development and well-being.

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

Rhythm perception, production, and synchronization during the perinatal period

Sensori-motor synchronization (SMS) is the coordination of rhythmic movement with an external rhythm. It plays a central role in motor, cognitive, and social behavior. SMS is commonly studied in adults and in children from four years of age onward. Prior to this age, the ability has rarely been investigated due to a lack of available methods. The present paper reviews what is known about SMS in young children, infants, newborns, and fetuses. The review highlights fetal and infant perception of rhythm and cross modal perception of rhythm, fetal, and infant production of rhythm and cross modal production of rhythm, and the contexts in which production of rhythm can be observed in infants. A primary question is whether infants, even newborns, can modify their spontaneous rhythmical motor behavior in response to external rhythmical stimulation. Spontaneous sucking, crying, and leg movements have been studied in the presence or absence of rhythmical auditory stimulation. Findings suggest that the interaction between movement and sound is present at birth and that SMS can be observed in special conditions and within a narrow range of tempi, particularly near the infant's own spontaneous motor tempo. The discussion centers on the fundamental role of SMS in interaction and communication at the beginning of life.

Prenatal stress and development: beyond the single cause and effect paradigm

Our awareness of the causes of stress-induced developmental dysfunction has increased dramatically over the past decade, and it is becoming increasingly clear that a number of factors can have considerable impacts on the developing fetus. Although there is a tendency in investigations of developmental teratogens to attribute specific causes to adverse fetal outcomes, it is important we recognize that for most developmental dysfunctions it is unlikely a single cause, but yet a series of environmental insults combined with genetic predisposition that ultimately leads to a disease state. Nonetheless, a number of developmental teratogens, such as maternal psychological stress and chemical exposures, have been shown to increase the likelihood of developmental defects. These defects can manifest during development, leading to observable birth defects, or could become evident long after birth, even into adulthood. In addition, epigenetic mutations in the germline can alter the phenotype of successive generations through transgenerational inheritance, and in this way environmental factors can alter the developmental outcomes and disease predispositions of future generations. Understanding this complexity is essential to interpretations of causality in the studies of stress-induced developmental dysfunction and needs to be fully considered to more effectively interpret potential outcomes.

Relaxation during pregnancy: what are the benefits for mother, fetus, and the newborn? A systematic review of the literature

Previous studies have reported associations between maternal stress during pregnancy and obstetric outcomes as well as fetal development and neonatal adaptation. These findings highlight the importance of identifying pregnant women who experience severe stress and the need for interventions that commence early in pregnancy. The aim of this study was to review studies that investigated the effects of relaxation techniques during pregnancy, including maternal, fetal, and neonatal outcomes. In addition, studies examining maternal endocrine and physiological alterations were reviewed. PubMed was searched using the following key words: maternal well-being, maternal stress, relaxation techniques, pregnancy, fetal neurobehavior, fetal heart rate, neonatal adaptation, and neonatal behavior. (1) Relaxation had a positive impact on women's emotional state. (2) Pregnancy outcomes improved with fewer admissions to the hospital, fewer obstetric complications, longer gestation, reduction of caesarean sections, and fewer postpartum complications. (3) Fetal heart rate and fetal motor activity were reduced as a result of relaxation and therefore interpreted as improved result. (4) Higher-birth-weight and improved performance on the Neonatal Behavioral Assessment Scale was related to relaxation. (5) Relaxation training was associated with reductions in maternal physiological and endocrine measures. Relaxation during pregnancy is associated with salutogenic effects that include regulation of emotional states and physiology. Relaxation is also associated with positive effects both on fetal behavior and on obstetric and neonatal outcomes. Identifying pregnant women at risk and instituting treatment early in pregnancy could improve obstetric and developmental outcomes for both the mother and her fetus.

Maternal stress in pregnancy: considerations for fetal development

There is significant current interest in the degree to which prenatal exposures, including maternal psychological factors, influence child outcomes. Studies that detect an association between prenatal maternal psychological distress and child developmental outcomes are subject to a number of interpretative challenges in the inference of causality. Some of these are common to many types of prenatal exposures that must necessarily rely on observational designs. Such challenges include the correlation between prenatal and postnatal exposures and the potential role of other sources of shared influence, such as genetic factors. Others are more specific to this area of research. These include confounding between maternal report of child outcomes and the maternal psychological attributes under study, difficulties in distinguishing maternal stress from more ubiquitous aspects of maternal personality, and the lack of association between cortisol and measures of maternal psychological stress. This article considers these methodological issues and offers an additional methodology focused on fetal neurobehavior for discerning potential mechanisms that may mediate associations between maternal psychological functioning and the developing fetal nervous system.

Mother's depression at childbirth does not contribute to the effects of antenatal depression on neonate's behavioral development

BACKGROUND

Maternal depression is a worldwide phenomenon that has been linked to adverse developmental outcomes in neonates.

AIMS

To study the effect of antenatal depression (during the third trimester of pregnancy) on neonate behavior, preference, and habituation to both the mother and a stranger's face/voice. To analyze mother's depression at childbirth as a potential mediator or moderator of the relationship between antenatal depression and neonate behavioral development.

METHOD

A sample of 110 pregnant women was divided in 2 groups according to their scores on the Edinburgh Postnatal Depression Scale during pregnancy (EPDS; ≥ 10, depressed; <10, non-depressed). In the first 5 days after birth, neonatal performance on the Neonatal Behavioral Assessment Scale (NBAS) and in the 'Preference and habituation to the mother's face/voice versus stranger' paradigm was assessed; each mother filled out an EPDS.

RESULTS

Neonates of depressed pregnant women, achieved lower scores on the NBASs (regulation of state, range of state, and habituation); did not show a visual/auditory preference for the mother's face/voice; required more trials to become habituated to the mother's face/voice; and showed a higher visual/auditory preference for the stranger's face/voice after habituation compared to neonates of non-depressed pregnant women. Depression at childbirth does not contribute to the effect of antenatal depression on neonatal behavioral development.

CONCLUSION

Depression even before childbirth compromises the neonatal behavioral development. Depression is a relevant issue and should be addressed as a routine part of prenatal health care.

Eating as a neurodevelopmental process for high-risk newborns

Many high-risk and preterm infants have difficulty with successful feeding and subsequent optimal growth during their stay in the neonatal intensive care unit as well as in the months after discharge. Environmental, procedural, and medical issues necessary for treatment of the hospitalized infant present challenges for the development of successful eating skills. Emerging data describe eating as a predictable neurodevelopmental process that depends on the infant's organization of physiologic processes, motor tone and movement, level of arousal, and ability to simultaneously regulate these processes.

A melodic contour repeatedly experienced by human near-term fetuses elicits a profound cardiac reaction one month after birth

BACKGROUND

Human hearing develops progressively during the last trimester of gestation. Near-term fetuses can discriminate acoustic features, such as frequencies and spectra, and process complex auditory streams. Fetal and neonatal studies show that they can remember frequently recurring sounds. However, existing data can only show retention intervals up to several days after birth.

METHODOLOGY/PRINCIPAL FINDINGS

Here we show that auditory memories can last at least six weeks. Experimental fetuses were given precisely controlled exposure to a descending piano melody twice daily during the 35(th), 36(th), and 37(th) weeks of gestation. Six weeks later we assessed the cardiac responses of 25 exposed infants and 25 naive control infants, while in quiet sleep, to the descending melody and to an ascending control piano melody. The melodies had precisely inverse contours, but similar spectra, identical duration, tempo and rhythm, thus, almost identical amplitude envelopes. All infants displayed a significant heart rate change. In exposed infants, the descending melody evoked a cardiac deceleration that was twice larger than the decelerations elicited by the ascending melody and by both melodies in control infants.

CONCLUSIONS/SIGNIFICANCE

Thus, 3-weeks of prenatal exposure to a specific melodic contour affects infants 'auditory processing' or perception, i.e., impacts the autonomic nervous system at least six weeks later, when infants are 1-month old. Our results extend the retention interval over which a prenatally acquired memory of a specific sound stream can be observed from 3-4 days to six weeks. The long-term memory for the descending melody is interpreted in terms of enduring neurophysiological tuning and its significance for the developmental psychobiology of attention and perception, including early speech perception, is discussed.

Fetal response to abbreviated relaxation techniques. A randomized controlled study

BACKGROUND

stress during pregnancy can have adverse effects on the course of pregnancy and on fetal development. There are few studies investigating the outcome of stress reduction interventions on maternal well-being and obstetric outcome.

AIMS

this study aims (1) to obtain fetal behavioral states (quiet/active sleep, quiet/active wakefulness), (2) to investigate the effects of maternal relaxation on fetal behavior as well as on uterine activity, and (3) to investigate maternal physiological and endocrine parameters as potential underlying mechanisms for maternal-fetal relaxation-transferral.

STUDY DESIGN

the behavior of 33 fetuses was analyzed during laboratory relaxation/quiet rest (control group, CG) and controlled for baseline fetal behavior. Potential associations between relaxation/quiet rest and fetal behavior (fetal heart rate (FHR), FHR variation, FHR acceleration, and body movements) and uterine activity were studied, using a computerized cardiotocogram (CTG) system. Maternal heart rate, blood pressure, cortisol, and norepinephrine were measured.

RESULTS

intervention (progressive muscle relaxation, PMR, and guided imagery, GI) showed changes in fetal behavior. The intervention groups had higher long-term variation during and after relaxation compared to the CG (p=.039). CG fetuses had more FHR acceleration, especially during and after quiet rest (p=.027). Women in the PMR group had significantly more uterine activity than women in the GI group (p=.011) and than CG women. Maternal heart rate, blood pressure, and stress hormones were not associated with fetal behavior.

CONCLUSIONS

this study indicates that the fetus might participate in maternal relaxation and suggests that GI is superior to PMR. This could especially be true for women who tend to direct their attention to body sensations such as abdominal activity.

Mother's anxiety and depression during the third pregnancy trimester and neonate's mother versus stranger's face/voice visual preference

BACKGROUND

Neonates show visual preference for their mother's face/voice and shift their attention from their mother to a stranger's face/voice after habituation.

AIM

To assess neonate's mother versus stranger's face/voice visual preference, namely mother's anxiety and depression during the third pregnancy trimester and neonate's: 1) visual preference for the mother versus the stranger's face/voice (pretest visual preference), 2) habituation to the mother's face/voice and 3) visual preference for the stranger versus the mother's face/voice (posttest visual preference).

METHOD

Mothers (N=100) filled out the Edinburgh Postnatal Depression Scale (EPDS) and the State Anxiety Inventory (STAI) both at the third pregnancy trimester and childbirth, and the "preference and habituation to the mother's face/voice versus stranger" paradigm was administered to their newborn 1 to 5 days after childbirth.

RESULTS

Neonates of anxious/depressed mothers during the third pregnancy trimester contrarily to neonates of non-anxious/non-depressed mothers did not look 1) longer at their mother's than at the stranger's face/voice at the pretest visual preference (showing no visual preference for the mother), nor 2) longer at the stranger's face/voice in the posttest than in the pretest visual preference (not improving their attention to the stranger's after habituation).

CONCLUSION

Infants exposed to mother's anxiety/depression at the third gestational trimester exhibit less perceptual/social competencies at birth.

Psychological and psychophysiological considerations regarding the maternal-fetal relationship

The earliest relationship does not begin with birth. Pregnant women construct mental representations of the fetus, and feelings of affiliation or "maternal-fetal attachment" generally increase over the course of gestation. While there is a fairly substantial literature on the development and moderation of psychological features of the maternal-fetal relationship, including the role of ultrasound imaging, relatively little is known about the manner in which maternal psychological functioning influences the fetus. Dispositional levels of maternal stress and anxiety are modestly associated with aspects of fetal heart rate and motor activity. Both induced maternal arousal and relaxation generate fairly immediate alterations to fetal neurobehaviors; the most consistently observed fetal response to changes in maternal psychological state involves suppression of motor activity. These effects may be mediated, in part, by an orienting response of the fetus to changes in the intrauterine environment. Conversely, there is evidence that fetal behaviors elicit maternal physiological responses. Integration of this finding into a more dynamic model of the maternal-fetal dyad, and implications for the postnatal relationship are discussed. Research on the period before birth affords tremendous opportunity for developmental scientists to advance understanding of the origins of human attachment.

Prenatal origins of temperamental reactivity in early infancy

BACKGROUND

Temperament theory has long considered individual differences in reactivity and regulation to be present at birth. Recent evidence suggests that such differences may be present prenatally and moderated by maternal emotionality.

AIMS

To determine whether induced maternal emotional activation generates a fetal response and whether observed fetal responsivity is associated with early infant temperament.

STUDY DESIGN

Women viewed an emotionally evocative labor and delivery documentary at 32 weeks gestation while physiological indices were evaluated and their infant's temperament was assessed at 6 weeks postnatal age.

SUBJECTS

Participants were 137 pregnant women and their infants.

OUTCOME MEASURES

Maternal physiological (heart rate and skin conductance) and fetal neurobehavioral (heart rate and motor activity) data were collected during gestation in response to the stimulus. Infant temperament (irritability and consolability) data were based on observational methods after birth.

RESULTS

Fetuses reacted to maternal viewing of the video with decreased heart rate variability, fewer motor bouts, and decreased motor activity. There was correspondence between the nature of individual maternal physiological responses to the full video, as well as phasic responses to a graphic birth scene, and fetal responsivity. Fetuses that reacted more intensively to maternal stimulation were significantly more likely to become infants that demonstrated greater irritability during a developmental examination at 6 weeks of age.

DISCUSSION

These results support the presumption that early postnatal temperamental characteristics emerge during the prenatal period.

Fetal responses to induced maternal relaxation during pregnancy

Fetal responses to induced maternal relaxation during the 32nd week of pregnancy were recorded in 100 maternal-fetal pairs using a digitized data collection system. The 18-min guided imagery relaxation manipulation generated significant changes in maternal heart rate, skin conductance, respiration period, and respiratory sinus arrhythmia. Significant alterations in fetal neurobehavior were observed, including decreased fetal heart rate (FHR), increased FHR variability, suppression of fetal motor activity (FM), and increased FM-FHR coupling. Attribution of the two fetal cardiac responses to the guided imagery procedure itself, as opposed to simple rest or recumbency, is tempered by the observed pattern of response. Evaluation of correspondence between changes within individual maternal-fetal pairs revealed significant associations between maternal autonomic measures and fetal cardiac patterns, lower umbilical and uterine artery resistance and increased FHR variability, and declining salivary cortisol and FM activity. Potential mechanisms that may mediate the observed results are discussed.

11- to 15-Year-old children of women who danced during their pregnancy

AIM

To determine whether high levels of maternal physical activity (dancing during pregnancy), influenced the offspring.

MATERIALS AND METHODS

Sixty-four women (32 of whom had continued to dance for at least 2 months after the beginning of pregnancy) filled in a questionnaire to assess the health and behavior of their offspring, now 11-15 years of age.

RESULTS

More children born from women who had continued to dance during pregnancy needed to be rocked to sleep during their first year (p < 0.05). More children in the study group played musical instruments (p < 0.05). There were no significant differences between the groups regarding other parameters.

CONCLUSIONS

The greater need to be rocked to fall asleep and the attitude to play musical instruments recorded in the children of dancers may be related to prenatal maternal movement. But they may also be due to other causes as discussed.

Fetal response to induced maternal stress

BACKGROUND

Despite increased attention to the role of antenatal maternal psychological stress in postnatal development, remarkably little information is available on the nature of the intrauterine fetal response to maternal psychological state.

AIMS

To determine whether: (1) the fetus responds to maternal stress; (2) the fetal response changes over gestation; and (3) individual maternal and fetal response patterns are stable over time.

STUDY DESIGN

Induced maternal stress at 24 and 36 weeks gestational age using the Stroop color-word task.

SUBJECTS

137 low-risk pregnant women with normally developing fetuses.

OUTCOME MEASURES

Maternal (heart rate and skin conductance) and fetal (heart rate, heart rate variability, and motor activity) responses.

RESULTS

The manipulation evoked maternal sympathetic activation, which declined in magnitude from 24 to 36 weeks gestation. Fetuses responded to the manipulation with increased variability in heart rate (F(2,256)=7.80, p<0.001) and suppression of motor activity (F(2,216)=15.47, p<0.001). The magnitude of the fetal response increased over gestation. The degree of maternal reactivity to and recovery from the stressor were correlated over time (r's=0.53 and 0.60 for heart rate; r's=0.31 and 0.36 for skin conductance; p's<0.001). There was moderate stability in the magnitude of the fetal motor response (r=0.25, p<0.01).

CONCLUSIONS

Demonstration of fetal responses to maternal sympathetic activation evoked by a benign cognitive stressor suggests that fetal neurobehavioral regulation is routinely disrupted by maternal environmental intrusions. There is no evidence of a protective effect of diminished maternal sensitivity to stress on the fetus. Individual stability in the magnitude of the evoked maternal physiologic and psychological responses from 24 to 36 weeks and stability in the fetal motor response implies that characteristic response patterns emerge in utero. We propose that autonomic development is partially entrained through these processes.