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Introduction: The updated intrapartum cardiotocography (CTG) classification system by FIGO in 2015 (FIGO2015) and the FIGO2015-approached classification by the Swedish Society of Obstetricians and Gynecologist in 2017 (SSOG2017) are not harmonized with the fetal ECG ST analysis (STAN) algorithm from 2007 (STAN2007). The study aimed to reveal homogeneity and agreement between the systems in classifying CTG and ST events, and relate them to maternal and perinatal outcomes. Material and methods: Among CTG traces with ST events, 100 traces originally classified as normal, 100 as suspicious and 100 as pathological were randomly selected from a STAN database and classified by two experts in consensus. Homogeneity and agreement statistics between the CTG classifications were performed. Maternal and perinatal outcomes were evaluated in cases with clinically hidden ST data (n = 151). A two-tailed p < 0.05 was regarded as significant. Results: For CTG classes, the heterogeneity was significant between the old and new systems, and agreements were moderate to strong (proportion of agreement, kappa index 0.70–0.86). Between the new classifications, heterogeneity was significant and agreements strong (0.90, 0.92). For significant ST events, heterogeneities were significant and agreements moderate to almost perfect (STAN2007 vs. FIGO2015 0.86, 0.72; STAN2007 vs. SSOG2017 0.92, 0.84; FIGO2015 vs. SSOG2017 0.94, 0.87). Significant ST events occurred more often combined with STAN2007 than with FIGO2015 classification, but not with SSOG2017; correct identification of adverse outcomes was not significantly different between the systems. Conclusion: There are discrepancies in the classification of CTG patterns and significant ST events between the old and new systems. The clinical relevance of the findings remains to be shown. (Less)

Introduction: Traditional validation of umbilical cord blood samples with positive veno-arterial ΔpH and arterio-venous ΔpCO2 values confirms the source of samples, whereas negative Δvalues represent mix-up of samples. To investigate whether this is true, the distributions of V-A ΔpO2 and A-V Δlactate were also explored and related to clinical characteristics. In addition, different cord blood sampling techniques were evaluated. Material and methods: Register study with cord blood acid-base and clinical data from 27 233 newborns. Clinical characteristics were related to positive, zero and negative Δvalues. Blood samplings from unclamped and double-clamped cords were compared. A two-sided P < 0.05 was considered significant. Results: ΔpH and ΔpCO2 values distributed into positive, around zero, and negative sub-populations, with significant differences in pH and clinical characteristics between sub-populations. No such sub-populations were distinguished for ΔpO2 and Δlactate. The 2.5th and 5th ΔpH percentiles were 0.013 and 0.022, respectively, and for ΔpCO2 0.30 and 0.53 kPa. Applying 5th percentile criteria resulted in 3.5% of “approved” cases showing a ΔpO2 ≤ 0. Puncture and sampling of the unclamped cord resulted in significantly better sample quality. Conclusions: Unphysiological negative ΔpO2 values occurred despite correct validation with traditional criteria. Δlactate cannot be used for validation because both positive and negative values are physiological. Positive/around zero/negative ΔpH and ΔpCO2 sub-populations were associated with significant differences in pH and clinical characteristics, indicating that defective sampling and sample handling are not the sole explanations for negative Δvalues. Prompt puncture and sampling of the unclamped cord resulted in best sample quality. (Less)

INTRODUCTION Fetal heart rate short term variation (STV) decreases with severe chronic hypoxia in the antenatal period. However, only limited research has been done on STV during labor. We have tested a novel algorithm for a valid baseline estimation and calculated STV. To explore the value of STV during labor, we compared STV with fetal scalp blood (FBS) lactate concentration, an early marker in the hypoxic process. MATERIAL AND METHODS Software was developed which estimates baseline frequency using a novel algorithm and thereby calculates STV according to Dawes and Redman in up to four 30-minute blocks prior to each FBS. Cardiotocography traces from 1070 women in labor who had had FBS performed on 2134 occasions were analyzed. RESULTS In acidemic cases (lactate >4.8 mmol/L; Lactate Pro™), median STV 30 minutes prior to FBS was 7.10 milliseconds compared with 6.09 milliseconds in the preacidemic (4.2-4.8 mmol/L) and 5.23 milliseconds in the normal (

We have examined whether endothelin-1 (ET-1) and erythropoietin (EPO) in amniotic fluid, and EPO in fetal serum obtained by cordocentesis from fetuses with signs of intrauterine growth retardation (IUGR), were correlated to fetal growth and/or chronic fetal hypoxia.Amniotic fluid and fetal serum were obtained by cordocentesis from 28 fetuses suspected to have IUGR and subsequently analyzed for EPO and ET-1 by ELISA. These data were correlated to blood gas results and fetal/maternal parameters at delivery.A novel finding was that ET-1 correlated to PO2 in amniotic fluid. The average level of ET-1 in amniotic fluid was 48.3+/-4.7 pmol/L. The results also showed a correlation between EPO levels in amniotic fluid and EPO in fetal serum. Furthermore, EPO correlated weakly to birth weight at delivery. Children with the lowest birth weights had the highest EPO levels. High EPO values, similarly to ET-1, correlated to low pO2 values. The level of EPO in amniotic fluid was 8.0+/-1.6 mIU/ml and in cord blood 29.5+/-9.6 mIU/ml.The results indicate that ET-1 levels may be a marker for short-term hypoxia, but not for fetal growth, since ET-1 in amniotic fluid was correlated to PO2 at the time of cordocentesis, but not to birth weight. The results also indicate that EPO levels in amniotic fluid and in fetal cord serum are highly correlated, and thus both can be used as markers for fetal growth and chronic hypoxia before the onset of labor.

Objective To assess the effect of the time interval from indication of hypoxia to delivery on neonatal outcome in high-risk pregnancies monitored with cardiotocography (CTG) and ST-waveform analysis. Design Prospective observational study. Setting University hospital, Norway, 2004–08. Population Singleton high-risk births with a gestational age above 35+6 weeks, monitored with CTG and ST-waveform analysis. Methods Logistic regression analysis and Kaplan–Meier survival plots. Main outcome measure Neonatal morbidity in relation to the rapidity of intervention. Results Of 6010 deliveries monitored with ST-waveform analysis, 1131 (19%) had an indication to intervene for fetal distress according to clinical guidelines. Those fetuses were at increased risk of an adverse neonatal outcome, and if delivered later than 20 min after the indication of hypoxia their risk increased further; i.e. transfer to the neonatal intensive care unit (NICU) from an odds ratio of 1.6 (95% confidence interval 1.2–2.2) to an odds ratio of 3.3 (95% confidence interval 2.5–4.3). The indication-to-delivery interval was longer for neonates with a 5-min Apgar score of

To evaluate the possible association between prenatal buprenorphine exposure and compromised early neonatal outcome in view of markers of perinatal hypoxia. DESIGN, SETTING AND SAMPLE: The study group consisted of 27 full-term neonates exposed to buprenorphine prenatally and prospectively followed up at a special tertiary outpatient clinic for pregnant drug abusers. Serving as controls were 27 full-term neonates exposed prenatally to illicit substances other than opioids and 38 full-term neonates from uncomplicated pregnancies of healthy parturients.Apgar scores, cord pH and base excess were recorded. Cord serum samples were collected at birth for analysis of biochemical markers of fetal hypoxic stress: erythropoietin (EPO; chronic hypoxia), cardiac troponin T (cardiac involvement) and S100 (neural damage).All infants were born in good condition according to Apgar scores and pH of cord blood. No statistically significant differences were found between the three groups in cord serum concentrations of EPO (33.0 median, range: 9.0-476.0 U/L in the buprenorphine-exposed group vs 27.0, range: 8.0-114.0 U/L in substance-abusing controls vs 28.1, range: 11.6-260.0 U/L in healthy controls) or S100 (0.47, range: 0.25-0.91 microg/L vs 0.40, range: 0.12-1.22 microg/L vs 0.47, range: 0.20-2.15 microg/L). No significant differences existed in cardiac TnT levels (0.017, range: 0.010-0.072 U/L vs 0.010, range: 0.010-0.075 U/L vs 0.024, range: 0.010-0.075 U/L).While no significant differences in asphyxia markers were observed between the three groups, a tendency towards higher levels of EPO emerged in the buprenorphine-exposed group.

Ischemia and subsequent reperfusion induce lipid peroxidation in the cerebrum of the fetal rat. The present study evaluated the antioxidant activity of endogenous coenzyme Q in protecting against the lipid peroxidation induced in the fetal rat brain by ischemia/reperfusion.We used wistar rats at day 19 of pregnancy. Fetal ischemia was induced by bilateral occlusion of the utero-ovarian artery for 20 minutes. For reperfusion, the occlusion was released and the circulation was restored for 30 minutes. Control rats underwent sham operation. We determined the levels of thiobarbituric acid-reactive substances, the concentrations of coenzyme Q9, coenzyme Q10, and the mitochondrial respiratory control index in fetal brains.Occlusion for 20 minutes significantly reduced the respiratory control index (p0.01), but did not alter the levels of thiobarbituric acid-reactive substances, coenzyme Q9 or coenzyme Q10. Subsequent reperfusion, however, significantly increased the level of thiobarbituric acid-reactive substances (from 6.53+/-1.54 to 11.46+/-3.31 nM/mg of protein, p0.01) and significantly decreased the level of coenzyme Q9 (from 291.73+/-108.94 to 162.44+/-56.83 pM/mg of protein, p0.05) and that of coenzyme Q10 (from 153.10+/-75.24 to 79.84+/-30.40 pM/mg of protein, p0.05). The respiratory control index was still significantly lower following reperfusion than in controls (p0.01). Significant negative correlations were observed between the level of thiobarbituric acid-reactive substances and the concentrations of either coenzyme Q9 (r = -0.68, p0.001) or coenzyme Q10 (r = -0.70, p0.001).Endogenous coenzyme Q may protect the fetal rat brain against the lipid peroxidation induced by ischemia/reperfusion.

A new test strip method was used to determine the lactate concentration in fetal scalp blood during normal labor. Sixty-six fetal scalp blood samples were collected at cervical dilatations between 4 cm and 10 cm. The mean lactate value was 1.7 +/- 0.8 mmol/l simultaneously (IS.D.) and the mean pH sampled simultaneously was 7.36 +/- 0.04 (IS.D.). The corresponding values for base deficit was 2.1 (+/- 1.9) and for pCO2 5.8 (+/- 0.8). No difference was seen in lactate concentrations or pH values in early compared to late first stage of labor. The mean lactate concentration in the umbilical artery immediately after delivery was 3.7 mmol/l +/- 1.2 (IS.D.). The method was easy to handle and gave the result within 60 seconds.

The fetal heart rate response to acute hypoxemia was observed during an accidental drop in oxygen concentration inspired by the mother in labor. There was a marked increase in FHR variability in the early stage of hypoxia and also during the recovery phase. While an increase in fetal heart variability is generally considered to be a normal physiological event, it may also indicate a state of fetal hypoxemia associated with an intact fetal circulation, and should be treated with caution during labor.

Maternal and fetal beta 1-adrenoceptor blockade was induced in sheep by infusing i.v. 11 pregnant ewes with metoprolol in doses producing maternal plasma concentrations of metoprolol comparable to those obtained in clinical use. Ten other ewes and their fetuses served as controls. Under acute anaesthesia the fetus was exteriorized and subjected to two levels of controlled asphyxia by intermittent, complete obstruction of the maternal placental blood flow. Fetal haemodynamic reactions were assessed by measuring fetal heart rate, cardiac contractility, cardiac output and cerebral blood flow. The metabolic reactions were evaluated from blood gases, pH, lactate and hypoxanthine concentrations, while the electrophysiological status of the brain was evaluated from the somatosensory evoked EEG potentials (SEP). Already during the period of moderate asphyxia the beta-blocked fetuses demonstrated a blunted haemodynamic response, in comparison with the control fetuses, resulting in an accelerating lactic acidosis, signs of a breakdown of intra-cellular energy-rich phosphates and an impaired cerebral function. During the period of severe asphyxia, both groups of fetuses exhibited signs of extensive cerebral deterioration. During the ensuing recovery phase, 80% of the control fetuses regained their brain function, as assessed by SEP, whereas this was true for only 30% of the beta 1-blocked fetuses. It is concluded that the ovine fetus relies heavily on greatly increased sympatho-adrenal activity to adapt itself to asphyxia and that blockade of the fetal beta 1-adrenoreceptors by maternal medication is a hazard to the potentially asphyctic fetus.

(1) Measurement of fetal scalp blood pH aids the detection of fetal asphyxia. The investigation is done on patients whose fetus is at increased risk of death. (2) Special care in the collection and measurement of scalp blood pH is necessary to obtain satisfactory results. A change of 0.05 pH unit is significant. (3) Acidosis is present when scalp pH is

Beat-to-beat variability has been suggested as a sensitive indication of fetal well-being. The suggestion originates from case reports of observed decrease in variability preceding clinical signs of fetal asphyxia and fetal death. Against this background a study was performed to evaluate possible changes in heart rate variability in relation to changes in fetal oxygenation. Chloralose-anesthetized sheep were used. Short-term hypoxia was produced without acidosis. The FECGs were recorded on magnetic tape and later analysed by scrutinizing each QRS complex prior to the trigger of a rate meter. The differential index (DI) described by Yeh and co-workers was chosen because it is easily computed and reflects the variability of coefficient of variation for two successive R-R intervals. In contrast to the generally held view of a progressive diminution of variability during the development of asphyxia, the variability was found to increase parallel with a decrease in fetal arterial PO2 determined on blood samples withdrawn at intervals and ranging between 26 and 10 mmHg. The correlation between variability and PO2 in the range below 8-10 mmHg is still to be determined.

(1982). The Influence of Gestational Age on the Ability of the Fetus to Pass Meconium in Utero: Clinical implications. Acta Obstetricia et Gynecologica Scandinavica: Vol. 61, No. 3, pp. 275-277.

Two-dimensional ultrasound in combination with a pulsed Doppler may be used during parturition to distinguish between the various causes of fetal heart decelerations during active labor: "placental insufficiency", umbilical cord compression, and, fetal head compression. One case of umbilical cord compression is presented to illustrate the possibilities.

This study was designed to test whether the fetal brain has an increased resistance towards asphyxia at high levels of blood-glucose, compared with low levels. 35 fetal sheep were exteriorized and investigated under general anesthesia. Cerebral blood flow (CBF) was estimated with the 133Xenon-washout method. Cerebral uptake of oxygen, glucose, and lactate was measured. Somatosensory evoked potentials (SEP) were recorded. The fetuses were subjected to controlled asphyxia by ventilating the ewes with gas mixtures low in oxygen. The blood sugar levels of the fetuses were varied over a four-fold range. During normal oxygenation of the fetus variations in the blood glucose concentration induced considerable changes in the cerebral glucose uptake, whereas CBF and oxygen uptake were unaffected. During asphyxia, hyperglycemia was associated with rapid development of acidosis and reduction in cerebral oxygen consumption together with deterioration of the neurophysiological characteristics of the brain. Far from being beneficial during asphyxia, fetal hyperglycemia appeared to reduce the tolerance of the fetal brain towards asphyxia. This report together with other evidence provides support for the view that extra glucose might be disadvantageous for the asphyxiated fetus.

Progressive changes in the ST-T period of the fetal electrocardiogram (FECG) were studied in 18 lamb fetuses, acutely exteriorized and subjected to graded hypoxia. The aim of the study was to compare the bipolar precordial lead (CR-lead) with the unipolar scalp lead, and to correlate the alterations in the FECG to blood-gas and acid-base status. The scalp lead gave less information regarding fetal condition and was more difficult to interpret than the precordial lead. This might be one factor in the controversy regarding the significance of alterations in the FECG during asphyxia and labor, since the scalp lead is used mainly in clinical situations. Our previous results demonstrating progressive changes in the ST-T period of the FECG during hypoxia in experimental animals and showing the same ECG changes in newborn human infants immediately after birth, were registered with the bipolar precordial lead. It is possible that a bipolar scalp lead might give more information regarding the fetal condition than the unipolar scalp lead mainly used in clinical practice.