Fetal mouth movements during behavioural states 1F and 2F

The aim of this study was to investigate the characteristics of mouth movements during behavioural states 1F (quiet sleep) and 2F (active sleep) in the near term human fetus. Thirty-six women participated. Fetal heart rate and fetal movements were recorded for 2 hours continuously. Videotapes with enclosed periods 1F and 2F were replayed to record fetal mouth movements in detail. During 1F, regular mouthing movements dominated (present in 74%), while jaw opening, yawn and grimace were only observed in 5 to 16% of the recordings. Tongue protrusion was not observed in 1F. In all 2F periods jaw opening was present (100%), while tongue protrusion, yawn and grimace were also frequently observed. Regular mouthing was observed in 2F in only two fetuses. For regular mouthing and sucking, onset-to-onset intervals of clusters, cluster duration, and number and frequency of movements within clusters were calculated. In all aspects the differences between these two types of movement were statistically significant. Within the clusters of regular mouthing a decline in the mouthing frequency was found. The data on fetal regular mouthing correspond with observations in the neonate.     

The effect of antenatal steroid administration on the fetal response to vibroacoustic stimulation

BACKGROUND: Betamethasone transiently suppresses multiple fetal biophysical activities, including breathing movements, limb and trunk movements, heart rate variability, and heart rate accelerations. Unnecessary iatrogenic delivery of preterm fetuses due to the false diagnosis of fetal compromise has been described in this setting. The sonographically observed startle response of the fetus to vibroacoustic stimulation has been described as another modality to provide reassurance about fetal well-being. It is unknown, however, whether the startle response is also suppressed by betamethasone. The purpose of this study was to examine the effect of betamethasone on this biophysical parameter. METHODS: A prospective cohort study. Vibroacoustic stimulation was applied to the maternal abdomen and fetal movement responses were sonographically observed prior to (0 hours), 48 hours after, and 96 hours after betamethasone administration. We recorded the presence or absence of the fetal startle response, and, if a response was present, graded semi-quantitatively the intensity of the movements (vigorous versus sluggish). RESULTS: Twenty-two of 26 fetuses (84.6%) displayed a vigorous vibroacoustic startle response prior to betamethasone administration, in comparison to three of 26 fetuses (11.5%) at 48 hours after exposure (p<0.0001). Eleven fetuses and eight fetuses displayed no startle response at all (p<0.0005), or a sluggish response only (p<0.0005) at 48 hours, respectively. At 96 hours after betamethasone exposure, no differences in the number of fetuses with a vigorous, sluggish, or absent response were observed in comparison to 0 hours. Stratification of cases by gestational age groups of 28-30 weeks versus 31-34 weeks showed similar response patterns. CONCLUSION: Antenatal betamethasone exposure transiently suppresses the sonographically observed fetal startle response to vibroacoustic stimulation. Accordingly, this modality cannot be used for the ascertainment of fetal well-being of steroid exposed fetuses. Betamethasone seems to suppress central nervous system dependent biophysical activities. including the brain-stem dependent vibroacoustic startle reflex.     

The effect of magnesium sulfate tocolysis on the fetal biophysical profile

The biophysical profile has proved to be a valuable tool for the assessment of fetal well-being, independent of gestational age. Magnesium sulfate is commonly used as a tocolytic agent, yet relatively little is known about its effects on the biophysical activities of the fetus. To investigate the effects of magnesium sulfate on the biophysical profile, we performed serial studies on patients who received tocolytic therapy with this agent because of preterm labor. A total of 16 women with 22 fetuses at 26 to 34 weeks' gestation in spontaneous preterm labor were studied. An initial biophysical profile was performed at the time of admission, and a second examination was performed when maternal serum magnesium levels reached 6 to 8 mg/dl. On admission all fetuses had reactive nonstress test results and 21 of 22 (95%) demonstrated sustained fetal breathing movements. With magnesium sulfate tocolysis, 50% of fetuses had nonreactive nonstress test results, and only 4 of 22 (18%) demonstrated sustained fetal breathing movements. Fetal tone, gross body movements, and amniotic fluid volume were found to be unaffected by magnesium sulfate tocolysis.     

Gestational age and fetal biophysical assessment

With improved neonatal care, biophysical assessment to detect fetal asphyxia is used increasingly at an earlier gestational age. We have tested five fetal biophysical variables: nonstress test, fetal breathing movements, fetal movements, fetal tone, and amniotic fluid volume 11,012 times in 5582 singleton fetuses in whom there was a normal perinatal outcome. The nonstress test and fetal breathing movements were more likely to be abnormal at 26 to 33 weeks' gestation compared with 34 to 41 weeks. The nonstress test, fetal breathing movements, fetal tone, and amniotic fluid volume were more likely to be abnormal at 42 to 44 weeks' gestation compared with 37 to 41 weeks. Fetal biophysical tests should be interpreted in relation to gestational age.     

The effect of maternal fasting on the fetal biophysical profile.

OBJECTIVES: To determine fetal biophysical profile changes in women observing Ramadan with uncomplicated singleton pregnancy. METHODS: In this cross-sectional observational study healthy women who were observing Ramadan at 30 weeks or more of gestation were recruited as well as a non-fasting control group matched for age, parity, and gestational age. Ultrasound examination included assessment of amniotic fluid volume, fetal bladder volume, fetal biophysical profile, and umbilical artery Doppler flow. RESULTS: A total of 162 pregnant women were observed. Mean umbilical artery pulsatility index, vertical amniotic pool depth, and fetal bladder volume were similar in the study and control groups. However, there was a significant difference in biophysical scores between the two groups. In the fasting group, 30 of 81 fetuses (37%) had a score of 6/8 compared with 11 of 81 fetuses (13.6%) in the control group (P=0.001). All fetuses in both groups with a biophysical score of 6/8 showed no breathing movements. CONCLUSIONS: Fetal breathing movements are reduced during maternal fasting.     

Fetal heart rhythms during behavioural state 1F

Behavioural state 1F (quiet sleep) of the term fetus is defined on the basis of absence of eye and body movements, and the presence of a specific heart rate pattern (FHRP A), characterized by a stable heart rate with a small oscillation bandwidth. In the present paper the fetal heart rate pattern was studied in 39 enclosed periods with absence of fetal eye and body movements. In 37 periods the heart rate pattern met the criteria of FHRP A. Within FHRP A various distinct types of heart rhythm could be distinguished related to presence of breathing or regular mouthing and complete absence of movements. The bandwidth in the various heart rhythms differed significantly and was largest during breathing movements. During regular mouthing an oscillatory pattern was present with a frequency similar to the frequency of the clusters of mouthing movements. In 2 periods the heart rate deviated from the definition for FHRP A, i.e. a sinusoidal-like rhythm associated with sucking movements. These observations demonstrate the strong association between the fetal heart rate pattern and fetal movements during behavioural state 1F.     

The importance of the behavioural state in biophysical assessment of the term human fetus

We have examined how the different behavioural states exhibited by 78 healthy fetuses at term influence the result of the non-stress test (NST) and biophysical profile score (BPS). In association with state 1F the average recording time to obtain a satisfactory NST and BPS was 27.0 and 26.3 min respectively, and 52.6% and 44.0% respectively failed to achieve a 'normal' result. In contrast, satisfactory results were always obtained in the two active states (2F and 4F), and the average time was 3-5 min. Mature fetuses spend on average one third of the time in state 1F, and knowledge of its characteristics is therefore important, for the interpretation of biophysical tests. Our results suggest that continuation of biophysical recording for at least 40 min is necessary before an unreactive NST or low BPS should be regarded as suspicious. We suggest that interpretation of the NST and BPS should be made in the light of knowledge of normal patterns of behavioural development rather than using an arbitrarily defined scoring system.     

The importance of the behavioural state in biophysical assessment of the term human fetus

Summary. We have examined how the different behavioural states exhibited by 78 healthy fetuses at term influence the result of the nonstress test (NST) and biophysical profile score (BPS). In association with state 1F the average recording time to obtain a satisfactory NST and EPS was 27.0 and 26.3 min respectively, and 52.6% and 44.0% respectively failed to achieve a 'normal' result. In contrast, satisfactory results were always obtained in the two active states (2F and 4F), and the average time was 3–5 min. Mature fetuses spend on average one third of the time in state 1F, and knowledge of its characteristics is therefore important, for the interpretation of biophysical tests. Our results suggest that continuation of biophysical recording for at least 40 min is necessary before an unreactive NST or low BPS should be regarded as suspicious. We suggest that interpretation of the NST and BPS should be made in the light of knowledge of normal patterns of behavioural development rather than using an arbitrarily defined scoring system.     

An evaluation of antenatal fetal acoustic stimulation

Fetal heart rate reactivity was evaluated following acoustic stimulation testing (AST). The AST and NST (non-stress test) were compared with regards to certain adverse perinatal outcome criteria, and in a selected sample of cases, to other surveillance tests. These tests were the oxytocin challenge test (OCT) and biophysical profile (BPP). 479 tests were performed on 240 high-risk patients. The AST significantly increased fetal heart rate reactivity. With regards adverse perinatal outcome criteria, there was no significant difference between the AST and NST in relation to sensitivity, specificity or predictive values. In the 38 patients with both non-reactive NSTs and reactive ASTs, 5 (13.5%) had immediate follow-up surveillance tests (OCTs and/or BPPs) that were non-reassuring and necessitated delivery. In four of the five cases, there was evidence of potential fetal compromise. These preliminary observations suggest that the AST may have evoked reactivity in fetuses with early compromise, and raise concerns about replacing the NST with the AST as a primary screening test of fetal well-being.     

Computer-assisted assessment of the fetal biophysical profile

The biophysical profile assesses fetal heart rate, breathing movements, fetal body movements, amniotic fluid volume, and fetal tone. In the past, these data have been scored by an arbitrary, unweighted system. While this approach is useful in detecting major anomalies and oligohydramnios, both static observations, the dynamic variables (fetal heart rate, fetal breathing movements, and fetal body movements) have added little information beyond that of an extended nonstress test alone. We have evaluated an alternative biophysical assessment system, modeled after extended physiologic studies, which not only acquires dynamic fetal variables simultaneously but, with computer assistance, quantifies the biophysical information. With an ADR 4000/L scanner, a Hewlett-Packard 8040 A monitor, and a specially programmed IBM microcomputer, we studied 100 normal term fetuses during 60-minute epochs. Each gestation had normal amniotic fluid volume and fetal tone. Normative values for the dynamic variables, expressed as means +/- SD were: fetal heart rate, 137 +/- 6.3 bpm; incidence of fetal breathing movements, 25.0% +/- 17.3%; rate of fetal breathing movements, 46.0 +/- 9.4 breaths/min; total fetal breathing movements, 823 +/- 61; incidence of fetal body movements, 8.5% +/- 3.9%; accelerations (greater than 15 bpm, 15 seconds), 14.1 +/- 6.3. We conclude that this approach is practicable, respects the biologic cycles of fetal behavior, and provides a basis for population standards and sequential study of the same fetus.     

Intrauterine fetal activity in at term and prolonged pregnancies

Fetal body movements and breathing movements were recorded with a real time ultrasound scanner in 26 fetuses. There were two recording periods of 25 min each, before and half and hour after maternal IV administration of 50 gr glucose. Six fetuses were at 280 days of gestation (Group A), twelve fetuses were at 294 days of gestation (group B), eight fetuses at 294 days gestation were classified as stage I postmature (group C). The incidence of fetal body movements was not significantly different in the three groups. Maternal glucose administration had no significant influence on fetal body movements in any group. On the other hand fetal breathing activity was significantly increased in all three groups after maternal glucose administration. Breathing activity was significantly greater in group A when compared to group C in both recording periods, and when compared to group B in the period which followed maternal glucose administration. It is concluded that fetal breathing activity is reduced in prolonged pregnancies.     

Influence of the fetal scalp electrode stimulation test on fetal heart rate and body movements in quiet and active behavioral states during labor

Thirty women were studied to examine the effect of fetal scalp stimulation on fetal heart rate (FHR) accelerations and gross body movements in quiet and active fetal behavioral states during the active phase of labor. Stimulation was performed by five consecutive tractions of the fetal scalp electrode. Fetal response in terms of fetal movements and FHR accelerations occurring within 15 seconds after stimulation was observed in all fetuses of the active state group. In the quiet state group 14 of 15 fetuses responded with body movements and in 12 fetuses FHR accelerations were observed. Subsequently, most of the fetuses returned to the quiet state. We suggest that a normal and healthy fetus is expected to respond to the fetal scalp electrode stimulation test even in the quiet behavioral state.     

Comprehensive fetal assessment with three ultrasonographic characteristics.

OBJECTIVES: When three ultrasonographic characteristics--umbilical artery Doppler recording, growth (abdominal circumference), and biophysical profile score--are used in combination in assessment of fetuses at risk of chronic asphyxia: (1) What are the order and time scale for the development of abnormality with each characteristic? (2) What is the short-term outcome associated with abnormalities of the three characteristics? (3) Should we amend our fetal assessment protocol? STUDY DESIGN: An audit of 103 fetuses (100 mothers) referred to a tertiary center for fetal assessment because of suspected chronic fetal asphyxia was performed with three ultrasonographic characteristics, umbilical artery Doppler recording, measurement of abdominal circumference, and documenting the biophysical profile score. RESULTS: The order of deterioration (which had a very variable time scale) was umbilical artery Doppler recording, followed by abdominal circumference and finally biophysical profile score. Normal characteristics or an abnormal umbilical artery Doppler recording alone or an abnormal abdominal circumference alone was associated with an excellent prognosis. The worst outcome was found in the 28 fetuses with abnormality of all three ultrasonographic features before delivery. CONCLUSIONS: The main suggested implications for management are avoidance of preterm delivery with normal ultrasonographic characteristics, an abnormal umbilical artery Doppler recording alone, or an abnormal abdominal circumference alone; delivery of fetuses at greater than or equal to 34 weeks with abnormal umbilical artery Doppler recording and abdominal circumference before the biophysical profile score becomes abnormal; and implementation of specific measures to prevent necrotizing enterocolitis in newborns when all three characteristics are abnormal.     

Effects of acute hypoxemia on fetal movement in the fetal lamb

Chronically instrumented pregnant models were established using 5 Dorset-Rambouillet pregnant ewes with gestational age between 120 and 138 days. Observation of fetal movements were started on the 3rd postoperative day or later when recovery from the surgery to the physiological condition was confirmed by maternal and fetal biophysical parameters. Fetal movements were observed using real-time ultrasound equipment with linear-array transducer placed on the maternal abdomen. Observation encompassed the control period which lasted one hour followed by an experimental period of fetal hypoxemia created by decreasing maternal FIO2. Observation was also continued during the recovery period when the mother was re-exposed to room air. Maternal and fetal samples were periodically obtained during these periods. Frequency of fetal movements was studied in 10 minute periods under the control and hypoxemic conditions. All fetuses exhibited movements during the control period, ranging 1-42 movements/10 minutes, the mean incidence being 16.9 movements/10 minutes. During fetal hypoxemia (average PaO2 decrease: 8.6 mmHg), fetal movements were significantly reduced to 5.5 movements/10 minutes with complete cessation in some cases. In 4 animals which exhibited complete cessation of both fetal movement (FM) and fetal breathing movement (FBM), FBM disappeared before FM, and reappearance of FM was following by FBM during recovery from hypoxemia.     

Prognostic components of computerized fetal biophysical testing

Fetal biophysical testing with arbitrary scores for fetal heart rate (FHR), breathing movements, body movements, tone, and amniotic fluid volume has not proved to be highly sensitive or significantly better than FHR testing alone. Using a computerized analysis system for simultaneously acquired biophysical variables, we studied 200 high-risk fetuses near term. The dynamic parameters obtained for each fetus were compared with established nomograms, and overall test results correlated with the presence or absence of perinatal mortality, fetal distress, a 5-minute Apgar score less than 7, and intrauterine growth retardation for those delivered within 7 days of the last test. A test was considered abnormal if two or more parameters fell more than 2 standard deviations from the population mean. A decreased incidence of fetal body movements, amniotic fluid volume, and frequency of FHR acceleration were the most common individual test abnormalities. Test sensitivity (86%), specificity (89%), positive predictive value (75%), and negative predictive value (93%) exceeded those of the "standard" scoring approach and correctly identified all fetuses with malformation, perinatal death, and 19 of 22 fetuses with intrauterine growth retardation.     

Modified fetal biophysical profile in the assessment of perinatal outcome

The aim of the study is the evaluation of variables of the biophysical profile in the assessment of perinatal outcome. The prospective study included 87 pregnant women with singleton pregnancy in the 28th to 42nd week of gestation with clinically and ultrasonically verified fetal growth retardation, where the fetal biophysical profile was assessed antenatally. Through the factor analysis of biophysical profile variables we obtained values indicating the contribution of individual variables to the predictability of perinatal outcome. 70% of the patients were examined in 15 minutes according to the principles of modified biophysical profile. The most sensitive variable of the biophysical profile in the prediction of perinatal outcome was the amniotic fluid volume, followed by fetal breathing movements, non-stress test and fetal movements, while the lowest prediction value was assigned to the fetal tone. The modified biophysical profiles need to be perfected on a larger number of pregnant women, which would advance the predictability of this method in detection of hypoxically endangered fetuses.     

Relationship Between Combined Fetal Biophysical Activities,Oligohydramnios, and Fetal Acid–Base Status

The purpose of this study was to determine the relationship between combined fetal biophysical activities, oligohydramnios, and fetal acid-base status at the time of testing. In a prospective study of 101 patients undergoing cesarean section before the onset of labor, a fetal biophysical profile was performed within 3 h before the cesarean section. Different combinations of fetal biophysical activities (fetal heart rate reactivity, fetal breathing movements, fetal body movements, and fetal tone) and oligohydramnios were correlated with umbilical cord blood gas and acid-base measurements (artery and vein). Fetal acidemia was defined as umbilical arterial blood pH <7.20. The group of fetuses with reactive nonstress test (NST) and/or fetal breathing present had significantly higher pH, pO₂, bicarbonate, and base excess and significantly lower pCO₂ levels compared with fetuses who had nonreactive NST, absent fetal breathing, and compromised or absent body movements and tone. These blood gas and acid-base differences were observed in both umbilical cord artery and vein. There was a significant relationship between oligohydramnios and fetal acidemia. Seven of 15 (46.6%) fetuses with oligohydramnios were acidemic and 7 of 15 (46.6%) acidemic fetuses had oligohydramnios (P = 0.0008). Fetuses with compromised or absent movements and tone had the highest incidence of acidemia (10 of 11 or 91%) and oligohydramnios (4 or 11 or 36%). The presence of oligohydramnios was associated with increased frequency of acidemia in every combination of biophysical activities. However, when all biophysical activities were absent, the frequency of acidemia was 100% regardless of the presence or absence of oligohydramnios. In conclusion, progressive loss of fetal biophysical activities is associated with increasing frequency and severity of fetal acidemia and oligohydramnios.     

Quantitative analysis of fetal behavioural patterns with real-time sonography and the actocardiograph

Fetal heart rate patterns, isolated and clustered fetal movements, fetal eye and breathing movements were analysed simultaneously and semiquantitatively in 20 uncomplicated pregnancies in accordance with the classification of fetal behavioural states by Nijhuis and with the aid of two ultrasound scanners and the actocardiograph. According to our own definition state 1 F, 2 F, 3 F and 4 F were observed in 29, 34, 8, and 14% of the registration time. In 15% no state could be identified. Using only the actocardiograph state 1 F, 2 F and 4 F could be identified in around 75%. Periods without a state diagnosis could not be assessed by the actocardiograph alone. The combination of the actocardiograph and one ultrasound scanner for the observation of fetal eye movements reached a similar diagnostic accuracy as the polygraphic monitoring with two ultrasound scanners.     

The relationship between fetal activity and behavioral states and fetal breathing movements in normal and growth-retarded fetuses

The incidence of fetal breathing was studied during the course of behavioral state observations on 28 low-risk fetuses between 32 and 40 weeks' gestational age and on 12 growth-retarded fetuses between 36 and 40 weeks. Real-time ultrasound scanners were used to detect fetal eye, body, and breathing movements, and the fetal heart rate was recorded continuously. The mean duration of the observation sessions was 110 minutes. The mean incidence of fetal breathing was greater during periods of fetal activity (body and eye movements present, greater heart rate variability) than during quiescence (body and eye movements absent, narrowed heart rate variability) at all gestational ages studied in both low-risk and growth-retarded fetuses. During periods when one of the state variables (body movements, eye movements, heart rate pattern) was in its active condition while the other two were quiet, or the reverse, the incidence of fetal breathing was intermediate between those found when all three state variables were in agreement. After behavioral states had developed, at 38 and 40 weeks, the mean incidence of fetal breathing in the low-risk fetuses was greater during active states than during the quiet state. There was no apparent increase in the degree of linkage between fetal breathing and other expressions of fetal activity after the emergence of behavioral states.     

Longitudinal measurements of fetal breathing, body movements, heart rate, and heart rate accelerations and decelerations at 24 to 32 weeks of gestation

Fetal breathing, fetal body movements, fetal heart rate, and fetal heart rate accelerations and decelerations were studied longitudinally in healthy fetuses between 24 and 32 weeks' gestation in the second and third hour following an 800 kcal maternal meal. The expected increase in fetal breathing following a maternal meal was not seen until fetuses were at 30 to 32 weeks' gestation. The number of body movements decreased and the interaction between body movements and fetal heart rate accelerations became more evident as fetuses became older. Fetal heart rate decelerations increased with gestational age, and the relative proportion of total decelerations that were either associated with body movements or were part of a deceleration/acceleration/deceleration complex increased from 24 to 32 weeks' gestation. The data support the hypothesis that gestational age is an important variable to consider when interpreting biophysical measurements in the human fetus at 24 to 32 weeks' gestation. Fetal body movements may be the single most important measurement of fetal health at these gestational ages.