Fetal Monitoring

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Hans van der Slikke, MD:  "It's September of 2001, and we're in Barcelona at the 5th World Congress on Perinatal Medicine. Next to me is Marita Kuhnert from Marburg, Germany. Welcome, Marita."

Marita Kuhnert, MD:  "Thank you, nice to meet you again."

Hans van der Slikke, MD:  "Nice to meet you again. You're in a session about fetal monitoring and the organizers supposes there's a controversy between fetal monitoring with CTG on the one side and on the other side is fetal monitoring with fetal pulse oximetry. What are you going to tell the audience?"

Marita Kuhnert, MD:  "For me, there's no controversy. I would say that the combination is adjacent to the CTG to have fetal pulse oximetry. CTG is a very, very fantastic tool in the way of the fetus intrapartum but it has some "side effects." We all know that sometimes the fetal heart rate patterns look very suspicious or pathological and we presume that the baby's not in a good condition and, therefore, it is possible that the doctor can be misguided. He will do a c-section, for instance, and the baby didn't need the c-section, it's in good condition but the fetal heart rate pattern was leading us in another direction and, therefore, we need something else besides this first screening tool - CTG, we need the fetal pulse oximetry. We have as a so-called gold standard what's called blood sampling that was introduced by Erich Saling in 1962 but we all know this is only a special method, it's invasive, it's a little bit traumatic for the fetus, and people don't like that. Parents and medical staff don't like it very much because it's a little bit complicated to get blood out of the fetal scalp and you don't have a continuous monitoring of the fetal well being, therefore, we need something else. We need a new tool which continuously monitors fetal oxygenation and that would be fetal pulse oximetry under some special conditions which I will explain this afternoon. That is to say we have to bear in mind special recommendations or guidelines to get the best benefit out of fetal pulse oximetry."

Hans van der Slikke, MD:  "You said one of the dangers of CTG is that some tracings can be interpreted as very dangerous and it's well known that it leads to a rise in the percentage of caesarian sections. Now the U.S. trial has been published and they wanted to show that by using the fetal pulse oximetry the number of cesarian sections went down which appeared to not be the case. How is that possible?"

Marita Kuhnert, MD:  "I think this American study was a little bit different concerning the one we are doing right now because they don't use fetal scalp pH sampling at the same time. We are doing a randomized control trial right now and one group is only suspicious or pathological CTG and fetal scalp pH sampling and the other one besides having CTG and FPA also has fetal pulse oximetry, and this is the big difference concerning the American study. They had an increase in dystocia and I think if you are measuring very exactly at a special stage of labor or special problems in obstetrics then you will get some more ideas on what is going on in this process. Perhaps, in former times the American colleagues didn't see so many problems which are really from dystocia. They thought it would be a pathological CTG which forced them to do the c-section but now they have a differentiation between a abnormal fetal heart rate pattern and other indications for a operative delivery or c-section."

Hans van der Slikke, MD:  "But you should say that as it is proved in literature that as long as you do a regular fetal blood sampling the number of cesarian sections goes down. So I could presume from this American study that maybe your study will show that the group with fetal blood sampling will have a lower cesarian section rate than the group with fetal pulse oximetry."

Marita Kuhnert, MD:  "No, I don't think so. We want to prove that we can lower this rate of c-sections a little bit more if we have a third adjacent tool. You have CTG and fetal blood analysis and it can lower the c-section rate and it can lower a hint more if you take a second adjacent tool which is the fetal pulse oximetry because it's continuously measuring the oxygen saturation of the baby, and if you do fetal blood sampling of the scalp then it's from time to time in an interval. It's invasive and people don't like to have a trauma on the baby's head, and that's something that also belongs to the part of psychology of parents. For me, if you can manage fetal pulse oximetry very well then you would be on the safe side but only under some special conditions, which I will describe this afternoon in my session, the so-called recommendations. This is to say to make things safe is to bear in mind special conditions. That's the same with cardiotocography, it's the same with fetal blood analysis, and this is also the same with the fetal pulse oximetry."

Hans van der Slikke, MD:  "How many patients do you want to include in your study?"

Marita Kuhnert, MD:

  "We have about 150. The Biostatistical Institute of the Marburg University has calculated this pilot study and they said to us we should start a pilot study with 150 patients, and this would be good for a first step of statistical evaluation."

Hans van der Slikke, MD: "So there's 75 patients in each group?'

Marita Kuhnert, MD: "In each group, yes."

Hans van der Slikke, MD: "Do you already have an idea of when this study will be finished?"

Marita Kuhnert, MD: "In the springtime of next year, perhaps earlier but this is my calculation. Springtime of 2002 will be the end of it and if we are lucky we will end it earlier."

Hans van der Slikke, MD: "Thank you very much. I'm looking forward to the results of your new study."

Marita Kuhnert, MD: "Thank you."