PubMed HealthSearch

SEARCH · PubMed Health

Results for “fetal”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The effect of fetal head compression and fetal acidaemia during labour on human fetal cerebral function as measured by the fetal electroencephalogram.

We investigated the effect of head compression and acidaemia during labour in 25 African primigravidae. Evidence that head compression had occurred during labour was confirmed by both clinical and radiological means at the end of a trial of labour. No significant difference could be demonstrated in the quantity of fetal electroencephalogram (EEG) abnormality that occurred in the groups with marked head compression as compared to the groups without marked head compression. Deterioration in the fetal EEG to a flat record known as electrocerebral silence (ECS) was associated with the development of acidaemia. As fetal heart rate (FHR) decelerations appeared the percentage of ECS in the fetal EEG record increased significantly (P less than 0.05), and likewise, as fetal acidaemia developed a highly significant increase in ECS in the fetal EEG was demonstrated (P less than 0.001). We concluded that in the management of trial of labour there was no significant deleterious change in the fetal EEG as a result of head compression, unless fetal acidaemia supervened. However, in the majority of these cases a significant increase in ECS to more than 20 per cent occurred in association with only moderate acidaemia (pH 7.25 to 7.30).

Acidosis

Fetal hemoglobin (HbF) synthesis in baboons, Papio cynocephalus. Analysis of fetal and adult hemoglobin synthesis during fetal development.

Fetal hemoglobin (HbF) and adult hemoglobin (HbA) synthesis was studied in fetal baboons, Papio cynocephalus, to determine the normal pattern of hemoglobin production during fetal development. Fetuses ranging from 53 to 180 days gestation (term gestation 184 days) were used. Erythroid cells were incubated with 3H-L-leucine, and the rates of globin chain synthesis and the distribution of radioactivity into hemoglobin intermediates and completed hemoglobin molecules were determined. Gamma chain synthesis accounted for approximately 97% of the total nonalpha chain synthesis up to 140 days gestation; beta chain synthesis accounted for the remainder. After 140 days gestation, approximately equal quantities of gamma and beta chain were synthesized in the bone marrow. Prior to 140 days gestation, total alpha chain synthesis was 30% greater than total non-alpha chain synthesis, while there was balanced chain synthesis after 140 days gestation. During the period of excess alpha chain synthesis, fetal erythrocytes contained a large pool of alpha-hemoglobin (alpha chain with heme attached) molecules uncombined with beta or gamma chains. In view of the possibility that alpha chains may have a lower affinity for gamma chains than beta chains, excess alpha chain synthesis may be required to maintain low levels of free gamma chains.

Animals

[A fetal distress signal: decreased fetal movements. A case of antenatal anaemia (author's transl)].

The authors report an observation of antenatal anaemia which showed as fetal distress found by a decrease of fetal movements and confirmed by cardiotocography. At birth, the baby was very pale and has a severe anaemia. The authors have investigated the method introduced by Sadovsky for analysing fetal activity in which the woman counted her fetal movements in accordance with a time schedule. Normal fetal movements are an indication of fetal well-being. Decreased fetal movements may be an indication of chronic fetal asphyxia. In this case, cardiotocography has to be undertaken. Analysis of their results demonstrated the value of this method which appears to be useful particularly for the assessment of chronic fetal distress.

Adult

Steroid production by definitive and fetal zones of the human fetal adrenal gland.

This study was performed to assess the relative contributions of the fetal and definitive zones of the human fetal adrenal gland to "corticoid" (cortisol and perhaps other corticosteroids) and dehydroepiandrosterone sulfate (DHAS) production, and the possible regulatory role of ACTH and the fetal pituitary in the secretion of of these steroids. Corticoid and radioimmunoassayable DHAS or total aromatizable androgen secretion by the isolated definitive and fetal zones of the human fetal adrenal gland between 10-20 weeks gestation has been studied in a superfusion system. Different functional capacities of the two zones were seen; corticoids were found to be secreted primarily by the definitive zone, while DHAS was found to be the main secretory product of the fetal zone. Addition of ACTH (250 ng/ml) or fetal pituitary homogenate produced a 2- to 5-fold stimulation of corticoid production by the definitive zone at all gestational ages studied. DHAS secretion by the fetal zone was also stimulated by ACTH. These results indicate that the definitive and fetal zones of the human fetal adrenal gland at midgestation have the capacity to respond to ACTH with increased corticoid or DHAS secretion, respectively.

Adrenal Cortex Hormones

Assessment of fetal well-being: fetal movement count versus non stress test.

In this prospective study, comparisons were made between the results of fetal movement count as performed by either the attending staff or by the patients using the non stress test (NST). A total of 283 NSTs were performed in 200 patients who had singleton pregnancy of at least 32 weeks gestation with indications for assessment of fetal well-being. Fetal movement counts performed by the attending staff and by the patients were recorded on 241 and 170 occasions, respectively. The results showed that the best correlation between fetal movement count by the attending staff with NST was when the criteria of three or more fetal movements within 10 min was used. Likewise, the best correlation between fetal movement count by patients with NST was found when ten fetal movements within 2 h was used as a cut off point. The result of this study suggests the usefulness of fetal movement count performed either by attending staff or patients as a cheap and effective method of screening for good fetal well-being in places where NST is not readily available and may also be used as a screening for patients prior to further evaluation.

Female

The effect of umbilical vein occlusion on fetal oxygenation, cardiovascular parameters, and fetal electroencephalogram.

In 11 fetal sheep experiments, the blood pressure in the fetal aorta (FA) and in the umbilical vein (UV) was measured following umbilical vein occlusion (UVO), as was the fetal heart rate (FHR), pH, Pco2, and oxygen saturation (So2) in both fetal vessels, and umbilical blood flow (Qumb) of the common UV. The fetal electroencephalogram was recorded continuously throughout the experiment. The results (No. = 17) were grouped according to the response of FA So2 into moderate (So2greater than40 per cent, mean 49.8, S.D. 6.3, and severe So2less than40 per cent, mean 20.4, S.D. 9.2). After 8 to 10 seconds, the fetal blood pressure in FA increased. Umbilical vein blood pressure increased to 25 mm. Hg (S.D. 8) and 35 mm. Hg (S.D. 9) in the moderate and severe groups, respectively. As a result of the decreased perfusion pressure (FA-UV blood pressure) across the fetal side of the placenta, the Qumb fell from 147 ml. per kilogram per minute (S.D. 57) and 30 ml. per kilogram per minute (S.D. 55) to 84 ml. per kilogram per minute (S.D. 48) and 120 ml. per kilogram per minute (S.D.22), respectively. The fall in FA So2 was related to the decrease in Qumb: FA So2=37.6 x log Qumb - 22.8 (2alphaless than 0.001). There was a mild decrease in So2 from 70 to 55 per cent when Qumb fell from 250 to 120 ml. per kilogram per minute. Below 80 to 120ml. per kilogram per minute, the fall in FA So2 was almost linear. The So2 in the UV remained constant so that arteriovenous difference for oxygen (AV Do2) increased. Oxygen consumption decreased almost linearly when Qumb fell below 80 to 120 ml. per kilogram per minute. The fetal electroencephalogram showed no significant change in voltage and the faster activities. From these observations, it is concluded that a decrease in Qumb following UVO jeopardizes the fetus only if a critical Qumb of 80 to 120 ml. per kilogram per minute and fetal artery So2 of 50 to 60 per cent is achieved.

Animals

Fetal breathing movements and other tests of fetal wellbeing: a comparative evaluation.

Sixty pregnant women whose fetuses were considered to be at high risk were intensively studied with fetal and placental function tests. Fetal breathing movements were studied with real-time ultrasound and the amount of time spent breathing and the variability of the breath-to-breath interval were measured. A reduction in the amount of time the fetus spent making breathing movements and decreased variability were indicative of fetal compromise. When these results were compared with those of other tests of fetal wellbeing measurement of fetal breathing movements and ultrasound assessment of growth were more sensitive tests of fetal wellbeing than the biochemical measures (urinary oestrogen, human placental lactogen, pregnancy-specific beta-1-glycoprotein, and unconjugated oestriol concentrations) or fetal heart rate. The predictive value was highest with serum unconjugated oestriol but the results of other tests were similar. Study of fetal breathing movements or an ultrasonic assessment of growth may provide a better screening test for fetal compromise than biochemical estimations.

Estriol

Expression of fetal antigens in fetal and adult cells during long-term culture.

Expression of fetal antigens in early and late passages of tissue culture cells derived from C3H/HeN and C57BL/KaLw mouse fetal cells and from lung tissue of young C57BL/6N mice was investigated by the isotopic antiglobulin technique. The late passage lines of fetal cells had undergone "spontaneous" neoplastic transformation in culture. The antisera were produced by syngeneic immunization with 5000 R x-irradiated tissues from C3H/HeN and C57BL/6N fetuses of 1 to 2 weeks gestation. Fetal antigens were found to be retained even after 5 years in cell lines derived from fetal tissues. In these lines no consistent change in fetal antigen expression could be correlated with neoplastic transformation. In contrast, the early passages of adult cells did not have detectable amounts of fetal antigens. However, fetal antigen(s) was demonstrated in cells of the late passages, and cells of both lines grew as sarcomas when next assayed 55 days later. In addition, fetal antigens were also present in established tumor lines in culture.

Animals

Intrapartum fetal heart rate profiles with and without fetal asphyxia.

Fetal heart rate profiles for periods up to 12 hours prior to delivery have been reviewed in 515 patients with a fetus at risk. Mechanisms other than fetal asphyxia will cause fetal heart rate decelerations, and fetal asphyxia may in some instances develop in the absence of total or late decelerations. However, an increasing incidence of total decelerations and late decelerations and particularly a marked pattern of total decelerations and late decelerations are of value in the prediction of fetal asphyxia. Fetal heart rate deceleration patterns can predict the probability of fetal asphyxia at the time of initial intervention, while a progression of fetal heart rate deceleration patterns in the individual fetus can be of assistance in the subsequent scheduling of serial acid-base assessments during labor.

Asphyxia

Fetal breathing movements: antepartum monitoring of fetal condition.

Until recently, the relative inaccessibility of the human fetus to physical assessment has made antepartum assessment of its condition difficult. The development of methods for accurate antepartum fetal heart rate monitoring and the subsequent study of heart rate responses to various stimuli have resulted in a significant improvement in accuracy of antepartum fetal surveillance. The development of real time B-mode ultrasound enables the clinician to assess many additional fetal biophysical variables including fetal breathing movements. In our observations, the combination of heart rate and fetal breathing assessment has produced a significant improvement in differentiating the normal from the compromised fetus. The addition of other biophysical variables (tone, movements and amniotic fluid volume) have further refined the ability to identify the fetus at risk. At this point, we have evaluated only a few of many possible variables. It seems probable that, as other fetal biophysical variables are included with the overall assessment, for example fetal reflexes or fetal biophysical response to exogenous stimuli, the identification of the fetus at risk and the quantitation of the magnitude of risk will become increasingly more precise.

Female

Correlation of fetal heart rate-uterine contraction patterns with fetal scalp blood pH.

The significance of fetal heart rate-uterine contraction (FHR-UC) monitoring as a means of predicting the condition of the fetus during labor was studied by correlating 460 fetal pH determinations obtained from 216 patients with the analysis of the 20-minute FHR-UC record preceding the fetal scalp blood sample. Both qualitative and quantitative analyses of the FHR-UC record were performed. The results indicate a less than 10% chance of fetal pH less than or equal to 7.250 with an normal baseline FHR and no periodic changes or with periodic accelerations, early decelerations, and uncomplicated baseline bradycardia or tachycardia. Variable or delayed decelerations with a total surface area (TSA) of 1-100 for the 20-min period were associated with a fetal pH less than or equal to 7.250 in 23 and 34% of cases, respectively. Variable or delayed decelerations with a TSA greater than 100 had a 35 or 47% chance of fetal pH less than or equall to 7.250. It is concluded that FHR-UC monitoring can be used to screen the innocuous from the ominous periodic change but that fetal scalp blood pH must be obtained to identify accurately the true from the false-positive ominous pattern.

Female

Influence of fetal extracellular volume contraction on renal reabsorption of bicarbonate in fetal lambs.

In order to determine the renal threshold for bicarbonate in the fetal lamb and factors that may influence renal reabsorption of bicarbonate in the fetus, 18 acute fetal lamb preparations (110-140 days of gestation) were studied. In the first series of experiments involving nine fetuses, the renal bicarbonate threshold of normal fetuses varied from 12.0 to 23.5 mM/liter with a mean value of 17.7 +/- 1.37 mM/liter. This is significantly lower (P less than 0.005) than the value measured in five adult sheep of 28.7 +/- 1.68 mM/liter. There was a significant and positive correlation between the fetal plasma bicarbonate at threshold level and the fetal kidney weight, as well as fetal age. In a second series of experiments, the excretion of bicarbonate and sodium was studied in nine fetuses before and after dehydration by peritoneal dialysis. After peritoneal dialysis there was a significant decrease in urinary pH (P less than 0.025), bicarbonate excretion (P less than 0.001), sodium excretion (P less than 0.001), fractional excretion of sodium (P less than 0.01). When glucose was replaced by mannitol in the peritoneal dialysis fluid the effects on bicarbonate reabsorption paralleled those when glucose was present in dialysis fluid. It was also shown that when glucose was given intravenously to the fetus, up to a plasma concentration of 200 mg/100 ml, there was no effect on the fetal renal reabsorption of bicarbonate. These data indicate that the low threshold for bicarbonate reabsorption by the fetal kidney is not due to a limited capacity to increase bicarbonate or sodium reabsorption and suggest that the fetal kidney is able to respond to volume depletion by increasing its reabsorption in bicarbonate and electrolytes.

Absorption

Fetal heart rate monitoring in cases of decreased fetal movement.

Thirty pregnant women in the third trimester of pregnancy in whom fetal movements were reduced up to cessation, for at least 12 hours, were monitored for FHR. The FHR 12-48 hours after the cessation of fetal movements was pathological in 21 cases and normal in 9 cases. The most frequent pathological FHR changes were loss of beat to beat variation and variable decelerations. In the following 48 hours another four cases showed pathological FHR changes. One to four days before the reduced fetal movements only six out of 15 cases showed pathological FHR changes which were L.B.B.V. Meconium was found in only 50% of the cases. It is suggested that pregnant women, especially high risk cases, should record fetal movements as a screening method. FHR monitoring is also a valuable method for detecting antenatal fetal distress, and should be used as an adjunct to fetal movements recording. When acute fetal distress has been established by MAS alone or with FHR change, the fetus should be promptly delivered.

Bradycardia

Fetal activity and fetal wellbeing: an evaluation.

The clinical value of the 12-hour daily fetal movement count (DFMC) as a test of antepartum fetal wellbeing was assessed. The lowest 2-5% of 1654 DFMCs recorded by 61 women who subsequently delivered healthy infants fell below 10 movements per 12 hours. This level was taken as the lower limit of normal for clinical purposes. A normal DFMC in a population at risk was associated with a satisfactory fetal outcome. A low DFMC was associated with a high incidence of fetal asphyxia, and when fetal death occurred fetal movements rapidly diminished and stopped 12 to 48 hours before death. The DFMC is a generally applicable method of monitoring fetal welfare during pregnancy which provides an inexpensive adjunct or even an alternative to the more expensive placental function tests in current use.

Apgar Score

Integrated interpretation of fetal heart rate, intrauterine pressure and fetal transcutaneous PO2.

By a study of the patterns of changes and the temporal relationship in fetal heart rate, intrauterine pressure, fetal tcPO2 and 'flow', a series of ten typical examples of combined patterns are described. Fetal tcPO2 is affected by the level of the fetal oxygenation and by the blood flow beneath the electrode. Should the latter be below a certain critical level fetal tcPO2 will be lower than fetal scalp blood PO2. By the integrated analysis of the four simultaneously recorded variables the different factors dominating fetal tcPO2 may be identified.

Female

[Study of fetal heart rate in deliveries complicated by fetal acidosis].

A study has been carried out on the parameters of the graph of the fetal heart rate (the basal rate and dips) in 44 cases of acute fetal distress with a pH lower than 7.2 in the blood and in 30 normal deliveries. The statistical analysis confirms that there is a significant rise in the number of heart rate abnormalities such as persistent bradycardia or persistent tachycardia and with dips during deliveries with fetal acidosis. The frequency of these abnormalities increases with the degree of acidosis. Sometimes the abnormalities in the fetal heart rate precede the appearance of the acidosis. All the same the discovery of these abnormalities does not by itself make a precise diagnosis of fetal distress because we do find these abnormalities in a certain number of cases even in normal deliveries. Only measuring fetal pH at a definite time can establish the diagnosis of fetal distress and the severity of the condition.

Acidosis

[The significance of fetal electroencephalography for the diagnosis of fetal disorders].

In typical cardiotocographic and bloodgasanalytic changes indicating fetal hypoxia the fetal electroencephalography shows frequency slowing, voltage suppression and spike activity. This EEG tracings simultaneously appeared with first cardiotocographic signs of fetal distress. It was not possible to recognize disturbances of fetal oxygenation in an earlier stage by EEG monitoring. Fetal EEG is of difficult technique and interpretation. In so far cardiotocography is of higher security, sensibility and easier handling for fetal monitoring. With regard to future improvements in electroencephalographic techniques it seems possible to get additional and more accurate informations for fetal monitoring and about perinatal morbidity.

Diazepam