In 13 normal pregnancies at 27-28 weeks of gestation the blood flow velocity waveform at the lower thoracic level of the fetal descending aorta was studied in relation to fetal heart rate pattern (FHRP), fetal eye movements (FEM) and fetal body movements (FBM). State parameter combinations in which high fetal heart rate (FHR) variability was present, were associated with a significant reduction in pulsatility index (PI) as compared with periods in which low FHR variability was present, irrespective of FEM and FBM, indicating a reduced peripheral vascular resistance. At 27-28 weeks of gestation FHR variability and PI might be linked to baroreceptor sensitivity. PI values derived from combinations FHRP-A, FEM(-), FBM(-) and FHRP-B, FEM(+), FBM(+) showed a significant inverse relationship (P less than 0.05) with FHR. FHR and FHR variability should be taken into account when studying flow velocity waveforms in the fetal descending aorta at 27-28 weeks of gestation.

Aorta, Thoracic↗

PubMedDate not supplied

Classification and quantitative aspects of fetal movements during the second half of normal pregnancy.

Qualitative and quantitative aspects of fetal behaviour were studied in nine healthy nulliparae during the second half of pregnancy. Continuous real-time ultrasound observations of 60 min duration were carried-out at four-weekly intervals from 20 to 36 weeks of gestation, using two dynamically focussed linear array transducers positioned lengthwise allowing viewing of sagittal sections through the entire fetus. Various movement patterns were classified according to de Vries et al. (de Vries, J.I.P., Visser, G.H.A. and Prechtl, H.F.R (1982): The emergence of fetal behaviour I. Qualitative aspects. Early Hum. Dev., 7, 301-22). The reproducibility as expressed by the mean standard deviation in the analysis of the percentage incidence of the different movement patterns was good (1.6-2.2%). Both the incidence and percentage of observation time in which general movements were present decreased with advancing gestational age. Breathing movements frequently occurred as an isolated phenomenon; occasionally they were associated with jaw movements, swallowing, hiccups or general movements. The incidence of breathing movements as well as the percentage of observation time in which breathing movements were present, demonstrated an increase up to 32 weeks with a drop at 36 weeks of gestation. Hiccups occurred episodically, following each other in regular succession. Both the incidence and the percentage of observation time in which hiccups were present fluctuated widely. Stretches and startles displayed a decrease in incidence with advancing gestational age, whilst eye movements showed an increase. Rhythmical jaw movements were often followed by swallowing. Occasionally, yawns or tongue movements were seen. They may be combined with breathing and general movements. The incidence of jaw movements increased up to 28 weeks with a decline after. Both brief and longer periods of hand-face contacts were documented with wide variation in incidence. Head rotations frequently occurred as a single event; the incidence showed a decrease up to 28 weeks followed by an increase at 36 weeks of gestation. The incidence of head retroflexion varied widely with gestational age.

Embryonic and Fetal Development↗

PubMedDate not supplied

Developmental course of general movements in early infancy. I. Descriptive analysis of change in form.

In order to describe the developmental changes of general movements (GM) in early infancy and to relate them to changes in other aspects of the neurological repertoire, the spontaneous motility in supine position was recorded on video tape at 4-week intervals in a group of twenty-two full-term healthy infants aged 2-18 weeks. Each follow-up session included a neurological examination. In newborn infants GM have a 'writhing' quality. The movements are characterized by a tight appearance, a relatively slow speed and a limited amplitude. The 'writhing' character of the GM is gradually broken down into a so-called 'fidgety' quality. These GM are typified by an ongoing flow of small movements occurring irregularly all over the body. The transformation of GM from a 'writhing' character into a 'fidgety' character was related more closely to postmenstrual than to postnatal age. 'Fidgety' GM were almost constantly present at the age of 8-12 weeks. In the third month very rapid arm movements ('swipes' and 'swats') occurred. The developmental changes in the form of the GM and those of the neurological repertoire showed no significant correlation. This demonstrates that within the normal CNS the various functional modules develop autonomously.

Age Factors↗

PubMedDate not supplied

Developmental course of general movements in early infancy. II. EMG correlates.

In order to study developmental changes in muscle co-ordination during the first postnatal months, simultaneous polymyographic recordings and video-recordings were made during spontaneous movements of 22 healthy infants, who were followed from birth onwards. During the first 2 months general movements (GM) change from movements with a so-called 'writhing' character, which have a tight appearance, a relatively slow speed and a limited amplitude, into GM with a 'fidgety' character, which consist of an ongoing flow of small, elegant movements. We hypothesized that this transformation would coincide with a change from a pattern of co-contraction of antagonistic muscle groups into a pattern of reciprocal activation. This was not the case, a pattern of co-activation of antagonistic muscle groups remained the prevailing pattern. With increasing age, we found shorter burst durations of phasic activity, an attenuation of burst amplitude and a decrease of tonic background activity. These changes were attributed to a reduction of the sensitivity of the motor units due to spinal and supraspinal reorganization. It is hypothesized that the so-called 'bistable' properties of motoneurones play a central role in the observed phenomena: in neonates motor units are apt at displaying sustained activity, at 2 months of age the threshold for reaching this maintained activity increases, resulting in a low level of excitation of motor units during spontaneous movements. In the third month rapid arm movements ('swipes' and 'swats') develop. The 'swats' are characterized by a consistent pattern of reciprocal activity of antagonistic (shoulder) muscles.

Electromyography↗

PubMedDate not supplied

Vestibulo-ocular response and its state dependency in newborn infants.

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Electroencephalography↗