F. Sierra

Clinical usefulness of pulse oximetry in the fetus with non-reassuring heart rate pattern?

Abstract The objective of this study was the evaluation of intrapartum pulse oximetry as an indicator of fetal distress and the condition of the newborn during clinical routine surveillance in an University Perinatal Center. Between 1998 and 1999 pulse oximetry (SpO2) was used additionally to routine fetal monitoring by electronic fetal heart rate tracing (CTG) and fetal blood sampling (FBA) in 128 cases with nonreassuring heart rate pattern. Cut off values were FIGO Score < 8 for the heart rate pattern and for fetal blood sampling during labor results of < 7.25 (preacidosis). The condition of the newborn was defined by the APGAR score with the cut off < 7 at 1 minute, while the biochemical status was evaluated by means of arterial blood sampling of the umbilical artery directly after birth using a pH of < 7.20 to verify acidosis. Predictive values of critically low SpO2 values (< 30 %) for at least 10 minutes as well as corresponding sensitivities and specificities were calculated together with 95% confidence intervals to identify fetal distress or a depressed condition of the newborns. Of 128 fetuses included in this study 66 (52 %) were born spontaneously, 23 (18 %) were born by operative vaginal delivery and 39 (31 %) by means of cesarean section. The high rate of cesarean section was due to cephalopelvic disproportion in 29 cases. Fetal outcome was evaluated with a clinical score: mean APGAR score value 8.5 SD ± 1. The mean value of the pH in the umbilical artery was 7.23 ± 0.04. During a SpO2 monitoring period of 18,381 minutes we analyzed a contact time of 63%. Comparing SpO2 values of < 30% with preacidosis in the fetal blood sampling, we found a positive predictive value of merely 0.17 (95% CI: 0.00–0.64). Of 9 preacidotic cases during delivery only 1 was indicated by a saturation value below 30% (sensitivity 0.11, 95% CI: 0.00–0.48). The specificity and negative predictive value were calculated as 0.83 (95% CI: 0.65–0.94) and 0.76 (95% CI: 0.58–0.89) respectively. Of eleven cases with acidosis in the blood of the umbilical cord artery, pH < 7.20, only 2 were indicated by a SpO2 values below 30 %. Which is equivalent to a sensitivity of 0.18 (95% CI: 0.03–0.52). Results of a receiver operator curve analysis showed no substantial deviation from the diagonal. The area under the curve was 0.62, the 95% CI (0.47–0.76) indicating no significant discrimination. Three of 49 fetuses with SpO2 recording during the last 10 minutes were born in clinical depressed status (APGAR< 7). None was indicated by a SpO2 value below 30 %. Conclusion: Fetal distress and impaired condition of the newborn are not identified or predicted during routine application of SpO2 monitoring in the fetus during labor with adequate safety.

Operative fetoscopical management of intrauterine obstructive uropathia by urethral stent.

Abstract We report on an innovative therapeutic attempt in a case with obstructive uropathia in a fetus. Placement of an anterograd urethral stent was performed in the 26th gestational week. Transurethral catheterization via the fetal megacystis, the urethra and the orificium externum of the penis was feasible during fetal endoscopy (Fetendo). During serial ultrasound scans from the 27th to the 36th gestational week a normalization of the amniotic fluid volume was observed. The postpartal evaluation demonstrated that the kidney structure, values of kreatinin serum levels and renal clearance were in the normal range. The boys development after the seventh month is completely normal. Fetendo with urethral stent application for obstructive uropathy should be performed for the carefully selected patient with oligohydramnion and normal kidney appearance.

Cerebral tissue oxygenation during hypoxia and hyperoxia using artificial placentation in lamb.

Aiming at a better understanding of the pathophysiologic basis of perinatal encephalopathy, we evaluated patterns of tissue oxygenation during hypoxia and hyperoxia. We utilized both laserspectroscopy and invasive tissue-Po2 microneed measurements synchronously in five newborn lambs (141-143 days of gestation). The model of artificial placentation provided defined changes of the blood gases, using a extracorporeal circuit with interposition of membrane lung. During hyperoxia, the Po2 at the blood outlet port of the lung was raised to > 300 mmHg for five minutes. During hypoxia, Po2 was diminished as oxygen at the gas phasis was replaced by nitrogen. After the induction of hyperoxia, a rise of tissue-Po2 was observed. The synchronously recorded data of the laserspectroscopy showed adequately rising HbO2 values in concordance (r = 0.97, p < 0.001). As a constant finding we did not observe Cyt-aa3 changes during induced hyperoxia with tissue-Po2 values of < 40 mmHg. Furthermore, no changes in blood volume occurred in this case. A different pattern of the laserspectroscopic parameters was found when the tissue-Po2 rose above a value of > 40 mmHg and Cyt-aa3 rose after a lag-time occurred. During induced hypoxia an immediate fall of tissue-Po2 corresponding with a fall of HbO2 in the spectroscopic tracing occurred (r = 0.87, p < 0.001). A fall of the Cyt-aa3 level was seen with a lag-time when the tissue-Po2 had reached values of below 10 mmHg. In addition, a rise of blood volume was recorded in all cases of induced hypoxia. In conclusion, the results indicated that cellular redoxe state remains stable over a large range of oxygen partial pressure changes.

Fetal Monitoring of Patients Diagnosed with Systemic Lupus Erythematosus – A Case Report

We report a case of pathological foetal Doppler velocity, specifically the absence of end diastolic flow in the umbilical artery (AEDV/REDV), suspected diabetic pregnancy and mesangioproliferative glomerulonephritis, at 32 weeks of gestation. The foetal heart rate tracings were evaluated using a computerised cardiotocogram (Oxford Sonicaid system 8002 Chichester, England) 1 for 20-30 min parallel to the routine cardiotocogram. The ultrasound control at 33 weeks of gestation showed oligohydramnion, foetal centralisation and reduced interval foetal growth. Due to small gestational age (SGA) and oligohydramnion, labour was induced at 36 weeks gestation with vaginal prostaglandin and an amniotomy. Due to cephalopelvic disproportion, a Caesarean section was performed. Signs and symptoms of neonatal lupus were not found.

Fetendo mit trachealer Okklusion bei Polyhydramnion und Tricuspidalinsuffizienz in einem Fall mit fetaler Zwerchfellhernie

Fragestellung: Die intrauterine Chirurgie bei CDH ist mit dem Ziel vorgeschlagen worden, das fetale Lungenvolumen zu augmentieren und die Hamodynamik zu normalisieren. Material: In einem Fall mit linksseitiger Zwerchfellhernie, Leberaszension und Dextroversion des Herzens fand sich in der 26 + 1 SSW eine Tricuspidalinsuffizienz. Bei Polyhydramnion bestand eine vorzeitige Wehentatigkeit sowie eine Cervixinsuffizienz (US <2,5cm Cervixlange). Das Lungenvolumen wurde uber die LH-Ratio mit <1 als gering eingeschatzt. Operation: Ein endoskopischer Eingriff erfolgte in der 27 + 1 SSW uber einen 0,8 Trokar bei simultaner ultrasonographischer Kontrolle. Es konnte uber ein flexibles Endoskop ein 0,4ml Ballon (GOLD VALVE, USA) intratracheal appliziert werden. Ergebnis: Postoperativ bildete sich die Tricuspidalinsuffizienz zuruck. Bei rucklaufigem Polyhydramnion sistierte die Wehentatigkeit. Eine Augmentierung des Lungenvolumens wurde ultrasonographisch indiziert. Komplikationen wie vorzeitiger Blasensprung oder ein Amnioninfektionssyndrom traten nicht auf. Diskussion: Die minimal invasive Technik der trachealen Okklusion durch Fetendo zielt zunachst auf eine Normalisierung des Polyhydramnions zur Vermeidung der drohenden Fruhgeburt. Als entscheidend fur die postpartale Adaptation bei Zwerchfellhernie gilt die begleitende Lungenhypoplasie. Die Problematik der Evaluation des Lungenvolumens vor dem Eingriff sowie nach Trachealocclusion erschwert eine definitive Einschatzung der Prognose. Die Mutter soll zur Optimierung der postnatalen Erstversorgung fur die in der 37/0 SSW geplanten Sectio in ein ECMO-Zentrum verlegt werden.

Quantitative ultrasonic tissue characterization of the cervix – a new predictor for prematurity?

Background:  Since the incidence of premature delivery has remained constant, despite intensive safeguard methods over the last decade, the texture features of the uterine cervix were evaluated using quantitative sonographic gray level analysis at different gestational ages (GA).