Fetal oxygen saturation during normal delivery

The aim of the study is to monitor fetal oxygen saturation--SpO2 during uncomplicated labour; to assess normal values and compare them to the data from fetal blood analysis and from clinical finding in the newborn. The study includes 53 pregnant women in term during active labour without evidence of fetal distress. Study is carried out with Nellcor-N 400--a system for measuring fetal pulse oxymetry and fetal pulse rate; oxygen sensor FS-14 and printer P-400 /Nellcor Bennet Incorporation/. Fetal pulse rate is monitored by cardiotograph Hewlett Packard. Mean duration of monitoring during first stage of labour is 98 +/- 48 min, versus 37 +/- 11 min during second stage. Mean values of SpO2 are 48.8 +/- 10% during the first stage of labor v/s 46 +/- 9.6% during second stage. Baby is born in good health--Apgar score more than 7 and mean pH value from umbilical artery 7.25. The conclusion is made that pulse oxymetry is an easy non invasive method for fetal monitoring without side effects concerning woman on labour and fetus. A relatively large range of variations of normal values is observed.     

Fetal oxygen saturation during epidural and paracervical analgesia

BACKGROUND: We wanted to assess changes in fetal oxygenation during maternal epidural or paracervical analgesia in labor. METHODS: A prospective, open and non-randomized study. Twenty healthy parturients were enrolled before they asked for pain relief. Informed consent was obtained. Fetal and maternal oxygen saturations were measured before and up to 1 h after the initiation of analgesia. Fetal oximetry was performed with the Nellcor N-400 oximeter+FS-14B fetal oxygen sensor (Nellcor Puritan Bennett, Pleasanton, California, USA). Maternal oximetry was done with Datex Satlite portable monitor (Datex, Finland). Visual analog scale was used for assessing pain relief. Two-way analysis of variance and students t-test were used for statistical analyses. RESULTS: Fetal oxygenation initially improved in both groups. The saturation then returned to baseline in both groups. In the epidural group, the values remained at baseline or slightly below, while in the paracervical group the saturation remained a little higher than baseline (p=0.009). No change was seen in maternal oxygenation or heart rate. No change in fetal heart rate was found either. Epidural block was superior to paracervical block with respect to pain relief (p=0.002). CONCLUSIONS: There was a small but significant difference in fetal oxygenation between epidural and paracervical groups during the observation period. The magnitude of the difference is hardly clinically significant. A larger, randomized study is needed to elucidate the mechanisms behind this finding.     

Fetal distress during labour in diabetic pregnancy

Summary. The frequency of fetal distress in labour was studied in 46 diabetic women and in 46 non-diabetic matched controls. Fetal distress was assessed by electronic fetal heart rate (FHR) monitoring and fetal scalp blood pH determinations in late first stage of labour. Ominous FHR and/or low pH (<7·26) was more common in the diabetic group than in the control group (17·4% and 10·9%, respectively) but the difference was not statistically significant. The frequency of caesarean section and low Apgar score at 1 min was significantly higher in the diabetic group ( P <0·05). There was no correlation between maternal blood glucose regulation and the occurrence of fetal distress in the diabetic group. The results suggest that fetal distress may be slightly more common in labour in diabetic women compared with controls managed in a similar way. Careful FHR monitoring and liberal use of fetal scalp blood pH determinations is recommended.     

Fetal arrhythmia during pregnancy and labour.

The significance of fetal arrhythmia presenting during pregnancy and labour has been examined in 68 patients. The different types of rhythm disorders diagnosed included 61 extrasystoles, 6 atrioventricular blocks and 1 auricular fibrillation. Extrasystoles were not associated with acidosis or organic cardiac disease. Atrioventricular block, though not associated with fetal hypoxia, was occasionally associated with congenital cardiac failure.     

Fetal distress during labour in diabetic pregnancy

The frequency of fetal distress in labour was studied in 46 diabetic women and in 46 non-diabetic matched controls. Fetal distress was assessed by electronic fetal heart rate (FHR) monitoring and fetal scalp blood pH determinations in late first stage of labour. Ominous FHR and/or low pH (less than 7.26) was more common in the diabetic group than in the control group (17.4% and 10.9%, respectively) but the difference was not statistically significant. The frequency of caesarean section and low Apgar score at 1 min was significantly higher in the diabetic group (P less than 0.05). There was no correlation between maternal blood glucose regulation and the occurrence of fetal distress in the diabetic group. The results suggest that fetal distress may be slightly more common in labour in diabetic women compared with controls managed in a similar way. Careful FHR monitoring and liberal use of fetal scalp blood pH determinations is recommended.     

Fetal carbon dioxide tension during human labour

Fetal carbon dioxide tension during labour is elevated in both metabolic and respiratory acidosis, but intermittent fetal blood analyses often fail to detect PCO2 changes during acute complications. Transcutaneous carbon dioxide monitoring is continuous and the possibility of diagnosing PCO2 changes is therefore better. The theoretical background for transcutaneous measurements and methods for clinical monitoring are described. Close correlations with capillary and arterial blood values have been found, and the atraumatic principle with a simple electrode application indicates a promising new method for acid-base assessment during human labour.     

Fetal scalp pH: practical value during labour

Metabolic acidemia may cause cerebral palsy or perinatal death. Its detection is the major goal of perpartum fetal evaluation. Sensitivity of continuous fetal heart rate analysis is excellent, but the lack of specificity of this test can lead to inadequate intervention during labour. Fetal scalp pH is directly reliable to fetal acid-base status. In every situation where fetal heart rate displays ominous pattern, a potential acidemia can be detected with fetal scalp pH analysis. Intervention is recommended in the next 30min when fetal scalp pH is bellow 7.20. Complete analysis of fetal acid-base status parameters, including base excess and lactatemia allows a more precise detection of metabolic acidemia. Described since 1962, the place of fetal scalp pH analysis is still central in our daily practice.     

Fetal heart rate monitoring during breech labour.

Forty-two breech deliveries were monitored throughout labour. Serious asphyxia at birth occurred in 15 babies, in every case preceded by abnormalities in the fetal heart rate. Interpretation of the records implicated umbilical cord compression as the likely cause of asphyxia.     

Fetal heart rate during labour: definitions and interpretation

Continuous fetal heart rate monitoring is widely used during labor even in low risk pregnancies. Consensus is necessary to define and interpret accurately the different FHR patterns. The normal FHR tracing include baseline rate between 110-160 beats per minute (bpm), moderate variability (6-25 bpm), presence of accelerations and no decelerations. Uterine activity is monitored simultaneously: contractions frequency, duration, amplitude and relaxation time must be also normal. Abnormal baseline heart rate during 10 minutes or more is termed tachycardia above 160 bpm (except for FIGO above 150) and bradycardia below 110 bpm. Variability is minimal below 6 bpm and absent when non visible. Decelerations are classified as early, variable, late, and prolonged. Early and late decelerations have an onset gradual decrease of FHR, in contrast variable decelerations have an abrupt onset. Early deceleration is coincident in timing with uterine contraction. Variable deceleration is variable in onset, duration and timing, and may be described as typical or non reassuring. Late deceleration is associated with uterine contraction; the onset, nadir, and recovery occur after onset, peak and end of the contraction. Prolonged deceleration is lasting more than two but less 10 minutes, with almost onset abrupt and no repetition. Electronic fetal monitoring is a method to detect risk of fetal asphyxia; analysis and interpretation of FHR patterns are difficult with a high false positive rate, increasing operative deliveries. The patterns who are predictive of severe fetal acidosis include recurrent late or variable or prolonged decelerations or bradycardia, with absent FHR variability, and sudden severe bradycardia. The other FHR patterns are not conclusive and defined as non reassuring; obstetrical risk factors must be considered and other method (like scalp sampling for pH) utilised to evaluate fetal state.     

Fetal arterial oxygen saturation (FSpO2) during the second stage of labor after training for childbirth

OBJECTIVE AND DESIGN: The aim of the research was to determine the effects of participating in training program for childbirth in Maternity School in Lód? on the state of the fetus. In the above research, the authors presented the foetal oxygen saturation (FSpO2) during the second stage of labour among the women participating in Maternity School as well as a control group. Our study analysed the neonatal outcome too (umbilical arterial blood pH and 5 min. Apgar score). MATERIAL AND METHODS: The test group consisted of eighty seven (87) healthy primigravidas of whom forty two (42) participated in classes in the Maternity School and forty fifth (45) made up the control group. Validity of the correlation was assessed by means of t-Student's table of N--2 degree of freedom. RESULTS: The medium parameters of FSpO2 values and duration of the second stage of labor in both groups were shown. Statistically significant differences between the groups were found in duration the second stage of labour--in Maternity School group being shorter. Statistically significant differences in FSpO2 values between groups were not observed.     

Fetal scalp blood sampling for pH and lactate measurement during labour

The wide use of continuous of fetal heart rate monitoring (FHR) since the seventies has been accompanied by an increase in cesarean delivery rates, without any decrease in cerebral palsy rate. Second line methods of fetal monitoring have been developed in order to better identify fetuses truly at risk of intrapartum asphyxia. The use of fetal scalp blood sampling (FBS) for fetal monitoring seems logical since neonatal acidosis is one of the major criteria of birth asphyxia. Studies show that the use of FBS reduces the increase in cesarean deliveries associated with the use of continuous FHR monitoring. However, FBS is invasive, non continuous and technically uneasy, with a rather high rate of failed blood samplings. Fetal scalp lactates measurement by micromethod requires a much smaller volume of blood. Although a wider assessment is required, the predictive value of fetal blood lactates seems to be similar to that of fetal scalp blood pH.     

Fetal cerebral blood flow velocity during labour. Preliminary report.

The authors have tried to ascertain in a preliminary study if monitoring of fetal cerebral blood flow velocity during labour could identify a situation threatening the fetal brain, which could justify a compulsory fetal extraction. Nine patients were explored at term during labour. The Doppler signal was recorded using the abdominal route at the level of the fetal internal carotid. The diastolic carotid index was used (DCI = D/S). In 5 cases, fetal heart rate (FHR) was normal during labour and the DCI was on average comparable for each of the patients and the mean DCI (20.1 +/- 1%) was in close agreement with the values normally seen after 33 weeks of amenorrhoea during pregnancy. The case of isolated deceleration shows that deceleration causes an almost instant drop in the telediastolic flux, but the index increases more rapidly than could be expected from the increase in cardiac frequency if this phenomenon were of purely cardiogenic origin. In the case of bradycardia, it was noticed that during the return to the initial FHR frequency, the DCI was much higher than during the measurements performed before bradycardia. In the 1st case of pathological FHR, the index was very high and remained elevated during all the observation period. The fetus presented at birth a normal Apgar score as well as normal blood pH and neurological examination. In the 2nd case of pathological FHR, the FHR was abnormal with decelerations, the DCI increased rapidly and remained high.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fetal transcutaneous carbon dioxide tension during the second stage of labour

Summary. Fifteen women were studied during the second stage of labour by measuring simultaneously fetal transcutaneous carbon dioxide tension (Tc Pco₂ and maternal end-expiratory Pco₂ . A linear increase of Tc Pco₂ with time was observed, predominantly because of changing maternal respiration patterns. The degree of maternal hyperventilation had no adverse effect on the status of the newborn infant.     

Fetal transcutaneous carbon dioxide tension during the second stage of labour

Fifteen women were studied during the second stage of labour by measuring simultaneously fetal transcutaneous carbon dioxide tension (Tc PCO2 and maternal end-expiratory PCO2. A linear increase of Tc PCO2 with time was observed, predominantly because of changing maternal respiration patterns. The degree of maternal hyperventilation had no adverse effect on the status of the newborn infant.