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Monitors for laser spectroscopy are available as an additional tool for foetal surveillance. Using this technique, continuous and non-invasive registration of four biochemical parameters (HbO2, HbR, blood volume and cytochrome aa3) can be performed. The calculation is based on the optical density after irradiation of the biological sample with pulsed laser light in the near-infrared range (755, 805, 845, 904 nm). We evaluated the new technique in a clinical trial of 20 patients. The application of the laser sensor was performed, using a modified amnioscope. During prenatal tracings in cases with suspect CTG patterns, hypoxia was not verified. In cases without late decelerations a decrease of the cytochrome aa3 signal was observed in less than 1%. During intrapartual measurements, near-infrared signals were compared with the result of the PO2 measurement in foetal blood analysis. We found a significant correlation for HbO2 and cytochrome aa3 with a correlation coefficient of r = 0.96 respectively r = 0.94. We conclude, that laser spectroscopy will potentially be of benefit for foetal monitoring as it might provide a basis for differentiation between foetuses at risk and non-hazardous cases.

It is the aim of fetoscopy to recognise or exclude malformations which are visible in the fetal stage and which are not associated with chromosomal damage. The requisite endoscope can be inserted practically without any problems into the amniotic cavity under local anaesthesia and in the manner of an "extended amniocentesis". If pregnancy is continued, the risk involed in fetoscopy must be assessed as similarly low as that of simple aminocentesis, as the clinical experience collected so far has shown. The clinical use of fetoscopy requires close co-operation with the geneticist and the parents concerned. The decision that fetoscopy is indicated lies mainly with the geneticist on account of the required expert genetic knowledge. Fetoscopy appears justified if there is an increased risk of malformation of the fetus which is manifest in the foetal stage and which is sufficiently serious to initiate therapeutic abortion if necessary, and, furthermore, if the risk involved in fetoscopy is in reasonable proportion to the risk of teh malformation. Over and above this, fetoscopy can also be justified if it is necessary to obtain fetal blood for examination. Satisfactory technical and endoscopic experience is the most important prerequisite for success and for reduced risk. Up to now, indication of fetoscopy was exclusively coupled to existing pregnancy and enhanced genetic risk. On the other hand, the question whether pregnancy should be permitted despite a known risk, simply because subsequent fetoscopy is envisaged, should be treated with reserve.

A fetoscope with a trocar of an external diameter of 3.9 and internal diameter of 2.9 mm was used. The optical equipment of the fetoscope had lenses with external diameters of 2.2 and 2.7 mm. The fetoscope can be inserted into the uterine cavity through the abdominal wall with local anaesthesia and insertion controlled by ultrasound. This type of insertion is uncomplicated and relatively free of risks. Thus an essential prerequisite for a successful fetoscopy is fulfilled. For the success of the fetoscopy, it is important to know what the diagnostic value of the procedure is and what can be seen through the fetoscope. The direct intrauterine visualization of the fetus or parts of the fetus is with the fetoscope under evaluation possible and was successful in 23 of 26 fetuses. The field of visualization is limited to 50 degrees by the optical system and only small parts of the fetus can be seen at a time. The extent of visualization of the fetus depends besides the optical system, on the quality of the amniotic fluid and the optimal timing of the fetoscopy in the second trimester between 15 and 18 weeks. Success is also dependant on the endoscopic experience and the technical training of the observer. After 13 of 26 fetoscopies the improvement was approximately 70%. Inspection of some parts of the fetus, for intance, the face is successful in every detail but still more or less fortuitous. Fetoscopy can only be deemed to be successful when a more or less total visualization of the fetus has heen accomplished. This was the case in 39% of the cases. Fetoscopy was used for diagnostic purpose in one case with the term delivery of a healthy infant. Fetal blood sampling by puncture of placental vessels under visualization is in its infancy. Fetoscopy is a justified procedure at this time in cases with a high genetic risk and for the avoidance of an abruptio.