Detection Of Fetal Hypoxia Research Articles

A Machine‐Learning Approach to the Detection of Fetal Hypoxia during Labor and Delivery

Labor monitoring is crucial in modern health care, as it can be used to detect (and help avoid) significant problems with the fetus. In this article we focus on detecting hypoxia (or oxygen deprivation), a very serious condition that can arise from different pathologies and can lead to lifelong disability and death. We present a novel approach to hypoxia detection based on recordings of the uterine pressure and fetal heart rate, which are obtained using standard labor monitoring devices. The key idea is to learn models of the fetal response to signals from its environment. Then, we use the parameters of these models as attributes in a binary classification problem. A running count of pathological classifications over several time periods is taken to provide the current label for the fetus. We use a unique database of real clinical recordings, both from normal and pathological cases. Our approach classifies correctly more than half the pathological cases, 1.5 hours before delivery. These are cases that were missed by clinicians; early detection of this type would have allowed the physician to perform a Cesarean section, possibly avoiding the negative outcome.

Doppler measurements of feto-placental blood stream in pregnant smokers

Introduction: Doppler analysis of the feto-placental and fetal circulation give dynamic information on the condition of the bloodstream during pregnancy, and early detection of fetal hypoxia. The objectives of the study were: testing whether there is influence of smoking on feto-placental circulation; determining whether there is a link to a number of smoked cigarettes during the day; assessing the benefits of Doppler ultrasonographic screening in detection of fetal hypoxia in pregnant women who smoke during pregnancy.Methods: 300 pregnancies were included in the prospective research. With regard to a number of smoked cigarettes the pregnant women were divided into three groups: I. the first group (moderate smokers) consisted of 100 pregnant women who smoked up to 15 cigarettes a day during pregnancy; II. the second group (heavy smokers) 100 pregnant women who smoked more than 15 cigarettes a day during pregnancy and III. the third group (control group) 100 pregnant women who did not smoke during pregnancy. All pregnant women underwent Doppler measurements of blood circulation (determination of resistance index – RI) in the umbilical artery, fetal aorta and middle cerebral artery.Results: The intensity of smoking has influence to circulation because RI in the umbilical artery and fetal aorta is increased and RI is decreased in the middle cerebral artery in pregnant women heavy smokers in comparison to pregnant women moderate smokers.Conclusion: Doppler sonography of the blood vessels could have an important role in detection of hypoxia and monitoring of the condition of the fetus of pregnant women who smoked during pregnancy.

FETAL BIOPHYSICAL PROFILE

To evaluate fetal Biophysical Profile as an effective technique for the assessment of fetal condition and to improve fetal outcome by early detection of fetal hypoxia. Design: Co relational study: Place and Duration of Study: The study was carried out for a period of one year from Oct 2004-Oct 2005 at Obstetrics and Gynecology Department of Fatima memorial hospital Lahore. Patients and Methods: All patientswith history of sluggish fetal movements and clinical suspicion of IUGR, were underwent BPP from 32-42weeks. 100 patients were selected and their BPP score was recorded and were followed till delivery. Those who went into spontaneous labor and who were induced monitored during labor and at any sign of fetal distress immediate caesarean section performed. APGAR score of newborn was noted at one and five minutes and those having poor APGAR score were resuscitated and were followed till one week after delivery. APGAR score was compared with BPP score. Results: During this study 100 BPP were performed. 34patients were primigravidas and 66 were multigravidas. Among 100 patients 73had a BPP score of 9-10/10, 21 patients had a score of 7-8/10 and 6 patients had 4-6/10.In 2 patients with 4/10score emergency caesarean section led to the delivery of neonates with APGAR score of 8 at 5 minutes. Majority of patients with normal BPS of 8-9/10 had good APGAR score of 7- 8/10.Only 8 patients having BPP of 9-10/10 had poor APGAR score 6/10 or <6/10. Conclusion: The fetal BPP appears to be an effective technique for assessment of fetal condition.

A Machine Learning Approach to the Detection of Fetal Hypoxia during Labor and Delivery

Labor monitoring is crucial in modern health care, as it can be used to detect (and help avoid) significant problems with the fetus. In this paper we focus on hypoxia (or oxygen deprivation), a very serious condition that can arise from different pathologies and can lead to life-long disability and death. We present a novel approach to hypoxia detection based on recordings of the uterine pressure and fetal heart rate, which are routinely monitored during labor. The key idea is to learn models of the fetal response to signals from its environment, using time series data recorded during labor. Then, we use the parameters of these models as attributes in a binary classification problem. A majority vote over several periods is taken to provide the current label for the fetus. We use a unique database of real clinical recordings, both from normal and pathological cases. Our approach classifies correctly more than half the pathological cases, 1.5 hours before delivery. These are cases that were missed by clinicians; early detection of this type would have allowed the physician to perform a Caesarean section, possibly avoiding the negative outcome.

PII: S0377-1237(09)80040-3

Electronic fetal monitoring (EFM) is the recommended method of intrapartum fetal surveillance for high risk pregnancies. Despite the questions about its efficacy and controversy regarding increased rates of operative delivery associated with its use, continuous cardiotocography (CTG) remains the predominant method of intrapartum fetal monitoring. The CTG trace also forms a central piece of documentary evidence in medico-legal cases related to intrapartum hypoxia and birth asphyxia.Although CTG is sensitive in detecting abnormalities of fetal heart rate (FHR), its specificity for detection of fetal hypoxia remains low and therefore confirmatory tests such as fetal scalp blood sampling (FBS) or analysis of fetal electrocardiography (ECG) become necessary. Due to the rising costs of litigations related to birth asphyxia and increasing complexity of obstetric patient populations, it has become absolutely mandatory that all health professionals responsible for the care of women in labour are trained adequately in interpretation and documentation of CTG traces, as well as the guidelines for actions based on the assessment of the trace and overall clinical situation.Confidential enquiries have always pointed to factors such as inability to interpret traces, failure to incorporate the clinical situation, delay in taking appropriate action and poor team working as contributors to adverse perinatal outcomes. In this article we discuss three case scenarios of adverse maternal and perinatal outcomes due to failure to adhere to basic principles of fetal monitoring and recommended actions as per the national guidelines. The key learning points and risk management issues are also discussed.

Intrapartum fetal surveillance

In spite of the significant increase in obstetric and neonatal interventions aimed at reducing asphyxia there is no reduction in the rate of cerebral palsy (CP). Metabolic acidosis occurs in 2% of all births and over 90% of such infants do not develop CP. About 10% of cases of CP are due to pathological events that occur after birth, 10–20% of cases are related to intrapartum events, and identifying the cause of the remaining 70% is an ongoing challenge for obstetricians and paediatricians. The original aim of continuous electronic fetal monitoring (EFM) was to prevent harm by detection of fetal hypoxia before it led to disability or death. It was soon realised that EFM had a high false-positive rate and there were no significant differences in outcome measures when compared with intermittent auscultation. The increased operative intervention rates associated with EFM were reduced if fetal scalp blood sampling (FBS) was performed to measure the pH. However, fetal blood sampling used for the diagnosis of intrapartum fetal hypoxia is time consuming and may be associated with equipment failure or inability to obtain a sample. As it is a single measurement it needs to be repeated, with consequent inconvenience to the woman and the staff. Additional or alternative methods are needed to help mothers and babies who, despite abnormal fetal heart rate patterns and clinical findings during labour and delivery, would not benefit from intervention. New methods of pulse oximetry and fetal ECG waveform analysis explore the possibility of continuous surveillance as an adjunct to EFM. Recent studies suggest that maternal pyrexia is associated with increased adverse fetal outcome. Monitoring of maternal temperature and its normalisation should be part of intrapartum care, to avoid fetal neurological injuries.

WS15‐05Fetal venous Doppler: is it helpful in timing of delivery of hypoxic fetus?

BackgroundThe aim of this study was to investigate the potential of fetal venous Doppler in detection of fetal hypoxia and timing of the delivery.MethodsThe study group consisted of patients with increased risk for developing fetal hypoxia. These were patients with diagnosed fetal intrauterine growth retardation (IUGR) and patients with pregnancy induced hypertension (PIH), or a combination of both problems. All patients had Doppler assessment of fetal arterial (umbilical artery, aorta, middle cerebral artery) and venous circulation (ductus venosus and umbilical vein), and cardiotocography 24 h before delivery. Collection of postnatal data included pH of umbilical chord blood, admission in neonatal intensive care unit, and perinatal death.ResultsA total of 360 patients were included in the study (IUGR 48%, PIH 20%, IUGR + PIH 32%). Deterioration in fetal venous return developed after fetal arterial circulation had been severely compromised. The decrease in end‐diastolic flow in ductus venosus anticipated development of umbilical vein pulsatile flow. Patients with pulsations in umbilical vein blood flow had high incidence of perinatal acidosis, morbidity, and mortality.ConclusionDelivery should be performed before umbilical vein pulsations develop. Careful monitoring of ductus venosus blood flow is helpful predictor of this event.

8 Fetal pulse oximetry

Fetal pulse oximetry provides a tool for the surveillance of the fetus at risk of hypoxia. The experience of 150 deliveries monitored by pulse oximetry and the analysis of data may allow preliminary recommendations for clinical use in cases of suspected fetal hypoxia based on a suspicious FHR. In most cases, saturation values above 33% suggest fetal well-being. Further fetal evaluation, for example by fetal blood samples or other means, is necessary to assess alterations of FHR pattern or decreases in saturation values. Pulse oximetry may allow a differentiation between cases that need further evaluation, such as scalp blood sampling, and those which do not. The number of repeated assessments may be reduced as long as the oxygen saturation and FHR pattern do not worsen. The effect of therapeutic measures on fetal oxygenation can be directly observed. The positive preliminary experiences with fetal pulse oximetry predominate even if high expectations of easy detection of fetal hypoxia have so far not been fulfilled.

Continuous monitoring of fetal oxygen saturation by pulse oximetry

To compare spectrophotometric saturation values of fetal blood sampling to the saturation readings by pulse oximetry. During a clinical trial, fetal oxygen saturation was monitored during labor by a fetal oxisensor and a fetal pulse oximeter. Fifty-one fetal scalp blood samples were assessed because of abnormal fetal heart rate (FHR) patterns. The pulse oximeter displayed only signal quality readings. The investigator had to perform adjustments if signal quality fell below 50%. After delivery, the saturation at the moment of fetal blood analysis could be read from a printout and compared to the saturation values of scalp blood sampling. The share of usable signal time was 51% overall, but only 40% in the 20-minute period during fetal blood sampling. Comparison with the reference method resulted in a median deviation of 6% (tenth percentile -10%; 90th percentile 18%) for pulse oximetry. The correlation coefficient between saturation values by pulse oximetry and fetal scalp blood sampling was 0.67. The correlation coefficient with the partial pressure of oxygen and oxygen saturation by pulse oximetry was 0.61, whereas it was 0.88 between partial pressure and saturation from the spectrophotometric analysis of the scalp sample. Fetal pulse oximetry corresponds satisfactorily to results from fetal blood analysis. Low invasiveness and continuous monitoring are the advantages of this method. At present, the available sensor generates only a limited amount of signal time. However, in combination with FHR monitoring, pulse oximetry promises greatly improved detection of fetal hypoxia.

Fetal electrocardiographic monitoring: past, present and future--a historical perspective.

The first recording of the fetal electrocardiogram was described 80 years ago. Since that time only the peak of the QRS complex has been used in fetal monitoring for the measurement of fetal heart rate. Attempts to quantify changes in the configuration and time constants have been attempted over the last 30 years but despite the data obtained from animal experiments suggesting configurational changes in relation to hypoxia, the problems of electrical noise and signal distortion have restricted the application of these observations in the detection of fetal hypoxia in the human. Recent technical developments have now enabled continuous real time monitoring of the PR interval, heart rate and ST segment, and their findings and the interrelationships between different variables suggest a new approach to precise monitoring of the fetal state.