Garite:	My name is Tom Garite. I am the professor and chairman of Obstetrics and Gynecology at the University of California at Irvine. I've had research interests in several clinical areas of Obstetrics but one that's pertinent to here has been, of course, antipartum and intrapartum fetal evaluation and have been raised and trained by several of the real founders of electronic fetal heart rate monitoring including Dr. Hahn, Hooligan and Freeman and others and so I've been interested in fetal evaluation for a long period of time. I've been frustrated by fetal heart rate monitoring because of its imprecise nature and the problems that have been caused as a result of that for many years and when the modalities begin to come along to more directly assess fetal oxygenation in labor, it was obviously an area of great excitement for me.
Van der Slikke:	Thank you. We'll talk a lot more about this the fetal monitoring and the way it's not, it's often frustrating but first, we continue around. Gary Dildy, please.
Dildy:	My name is Gary Dildy. I'm an Associate Professor of Obstetrics and Gynecology at the University of Utah Health Sciences Center in Salt Lake City. I'm also Director of Maternal-Fetal Medicine at Utah Valley Regional Medical Center in Provo, Utah. Upon completion of my fellowship in 1991, I became involved in research with the Nelcor Fetal Pulse Oximeter and over the course of the last seven years, we've monitored hundreds of patients at our location, in both an observational as well as during the randomized clinical trial.
Van der Slikke:	Thank you. We have David Swedlow.
Swedlow:	My name is David Swedlow. I'm a pediatrician and anesthesiologist. I've been associated with the company, Nelcor since 1987 and associated with the development of the Fetal Pulse Oximeter, both technically and clinically since the beginning of that project back in 1990. More recently I retired and I am now a technical and clinical consultant to Nelcor specifically dealing with this issue of fetal pulse oximetry.
Van der Slikke:	Thank you, gentlemen. So now, we know who we are and then our topic, the Fetal Pulse Oximetry. What's the aim, what's it for, what do we want to use it for? Can you comment on that, Tom?
Garite:	Yes, I can. If you look at the problems, in particularly associated with labor, that result in bad fetal outcomes and bad newborn outcomes, one quickly recognizes that this is one of the most dangerous periods of time in any human being's life, the twenty-four hours surrounding birth. And there are many causes of bad outcomes, but the one that is associated with labor in particular, is the failure of the baby to be adequately oxygenated in labor. Because this can result in death or neurologic damage or other organ system damage to the baby for oh, since about the turn of the century, physicians have tried to evaluate the fetus in labor and determine whether or not the fetus is adequately oxygenated and then develop ways of intervening to prevent such lack of oxygenation from resulting in any harm to the baby. That really is the aim of what we are talking about.
Van der Slikke:	I understand, but my question is then we have this fetal monitoring, the CTG and isn't that enough?
Garite:	Well, no it's not. If you really think about it and you look upon this issue as if you were never involved with heart rate monitoring at all, as a lay person, or let's say as an internal medicine physician, whatever, and you say, these people are trying to determine how well oxygenated the baby by looking at changes in the heart rate? That doesn't even make intuitive sense. Now there's some physiologic reasons why it does make sense, but at the very, very best, it's an indirect measurement of fetal oxygenation based on the response of the fetal brain as it's talking to the fetal heart in response to lack of oxygen and other reflexes that are associated with things that produce lack of oxygen. The problem is, it's only reliable when it tells you the baby is fine, and when it tells you the baby is fine, it's highly reliable; but it's highly imprecise when it is not totally reassuring, when it's not totally normal. That imprecision leads to too many cesarean sections, too many operative vaginal deliveries, many, many lawsuits and expectations of good outcomes that cannot necessarily be guaranteed but because of its imprecision and because of a great deal of disagreement in the interpretation.
Van der Slikke:	Thank you. Can you give an estimation about the amount of cesarean section that's done too much in the United States because of this problem? Tom, yes?
Garite:	That's an interesting question. If you want to do cesarean section for fetal distress or for insufficient oxygenation of the fetus, it would seem about the ideal number to do for that particular indication would be around 2%. That's based on the fact that about 2% of babies will have some metabolic acidosis as a result of inadequate oxygenation. A best estimate is that about 5-6% of cesarean sections are done nationally for non-reassuring fetal heart rate traces but that's the tip of the iceberg, you see. That says we're already doing three times more than we need to do under ideal circumstances, but there are also a number of cesarean sections for poor progress in labor, where the patient is not progressing well and there is some non-reassuring elements of the fetal heart rate and the combination of the two does not allow the physician to tolerate a normal length of labor and they may want to intervene early. And it's hard to say what percentage of cesarean sections for dystocia or failure to progress are done, because of concern over fetal heart rate but maybe anywhere from 30-60% of those, so it could be another 3-5%. So we may be talking about as many as 10% of all deliveries. And as many as half of all primary cesarean sections are done because of concern over the fetal heart rate tracing, that don't need to be done. Now they may end up being done later anyway, a great number of those for poor progress in labor, but at that the point that they're done in time, my estimate would be that as many as half of those cesarean sections could be not done, if we had a more precise and accurate way of measuring fetal oxygenation in labor.
Van der Slikke:	Yes, David, you want to comment on this.
Swedlow:	Yes, let me jump in and put some concrete numbers on what Tom has just said. If we take in round numbers, the fact that there are roughly 4 million or 4.1 million live births in the United States on a yearly basis; ten percent of that, to use Tom's numbers comes to about 400,000 cesarean sections whose motivating force is associated with some aspect of non-reassuring fetal distress. If half of those are, in retrospect, unnecessary and the actual number ought to be, say four or five percent instead of ten percent, then we're dealing with something in the neighborhood of 200,000 unnecessary cesarean sections, which of course are only known to be unnecessary in retrospect. You can't tell ahead of time given today's non-specific and high anxiety producing technology. Our experience in Europe and the experience here in the United States seems to be that one can identify about half of those patients as being well-oxygenated during the period of time that the obstetrical staff is concerned about their fetal heart rate tracing. Now that translates potentially to a reduction of the 400,000 cesarean sections to maybe, 200,000 cesarean sections. If you consider the cost differential, not price, not charged to the customer or to the mother, but the real cost differential of say, two, three or four thousand dollars between a vaginal delivery and a cesarean section, taking into consideration the increased length of stay, complications, etc., you begin to talk about say $3,000 times 200,000, it's a half a billion dollars a year in round numbers that the United States can look to save by simply giving the obstetrical staff, the nurses, the midwives, and the obstetricians, a better way to look at the fetus, a way to tell directly whether that child is well oxygenated or not well oxygenated.
Van der Slikke:	And you're saying, Gary.
Dildy:	Perhaps even more important is what happens down the road, in future pregnancies, these women go on and have repeat cesarean sections, several times over and sometimes after their second, third, or fourth cesarean section, they have complications related to these multiple operative procedures. Sometimes the baby suffers complications like a rupture of the uterus and asphyxia because of disruption of the blood flow that then the leads to direct fetal complications of future children that the mother has. So very often when I do cesarean section, I'm not so much concerned about the immediate consequences as to what happens during the remainder of that woman's childbearing lifetime and other problems and both medical as well as financial in the future deliveries.
Van der Slikke:	Thank you. So it's clear that there's a lot to be won in terms of well being of the mother in the first place and well being of the fetus of course, also.
Swedlow:	Let me interrupt for a minute. This is David again. I think that it's very clear that there's a positive benefit to accrue to the mom and to the fetus. I think it's also important that people understand there is potential positive benefit that accrues to the obstetrician, the nurse, the midwife, the entire obstetrical staff. Right now about 40-60% of all babies who are monitored have some period of time during labor during which their electronic fetal heart rate tracing is non-reassuring; that creates a very high degree of anxiety, concern, nervousness, worry, whichever word you want to place on that. Because the electronic fetal heart rate monitoring is so nonspecific, given the current state of the art in manual reading, that leads to a very large number of false alarms and a very high degree of anxiety in the obstetrical staff because of the concern about malpractice and doing right by the mother and the fetus which is the basic obligation of the physician and the medical community. The problem is that the only way they have right now of reducing that level of anxiety is to intervene; either pulling the kid out, grabbing the kid or operating and slashing the kid out. What fetal oximetry can do and it really has the potential to do, is to give the obstetrical staff, the nurse and the midwife, an objective tool to evaluate the fetus, without having to resort to the surgical intervention. And I think that it's very easy for us to focus on the benefits to the mother and to the fetus, they're pretty obvious and straightforward; the benefit to society being economic is also straightforward. But I can tell you from my past experience as an anesthesiologist, in the world of surgery, being able to reduce the level of anxiety that is associated with providing high quality care to your patients is a tremendous boon to the medical staff.
Van der Slikke:	Yes, it is. But we all know from literature that we can reduce that amount also by what we in Europe do a lot, fetal skull plate testing and I understand that's not very common practice here in the United States, isn't it?
Dildy:	Fetal scalp analysis is performed - excuse me, this is Gary Dildy. Fetal scalp analysis is performed in the minority of hospitals that deliver babies in the United States. This is different than some other countries such as in Germany and in Holland, but the problem with fetal scalp sampling is that it requires that the mother's cervix be dilated, that her membranes be ruptured, the fetal head be at a fairly low station or position. It's somewhat invasive in that the scalp has to be nicked with a small scalpel to obtain a blood specimen and it just gives you that information at that one specific point in time and sometimes the labor goes on for hours after that and the heart rate tracings remain non-reassuring or even worse for hours after that. As a result, in many hospitals, this procedure is not done at all. There are several studies that have been published out of the U.S. over the last ten years in hospitals where fetal scalp sampling is done, and they reported rates of utilization during labors has dropped from the mid-1980's from one to two percent to less than a fraction of one percent, without seeing any type of increase in fetal complications during the same period of time. So this technique of pulse oximetry has a dual theoretic advantage of perhaps, replacing fetal scalp blood sampling in hospitals where scalp blood sampling is performed and as a method of backup assessment where heart rate tracings are primarily monitored and scalp blood sampling is not utilized.
Garite:	This is Tom Garite again. If I may add one other thing. I think that one of the things that people don't appreciate about fetal scalp blood sampling is that the majority of fetal heart rate patterns that lead to anxiety and intervention are actually associated with umbilical cord compression, variable decelerations. In actuality, the vast majority of those patterns are not associated with metabolic acidosis but are associated with respiratory acidosis. And unlike the majority of people who get scalp pHs, you have to really get a complete set of scalp blood gases to sort out whether the baby has a respiratory acidosis or a metabolic acidosis. So even if you're doing a scalp pH, unless you're so good that you can actually get it between contractions which I've always found to be a joke, because having done many, many myself and someone in active labor having contractions every two or three minutes to get it in that little window between that is impossible. You have to run core gases and people don't do that. So you get a low pH, you're still going to get a baby that comes out screaming because that baby had nothing but a mild respiratory acidosis. So pH alone is not the right measure of fetal oxygenation and its end result of metabolic acidosis unless you have something which can sort out respiratory from metabolic acidosis. That's an important point.
Van der Slikke:	So gentlemen, you make clear that we need pulse oximetry, but actually how does it work? Dave, can I ask you to explain this?
Swedlow:	Yes, the technology is actually deceptively simple. Pulse oximetry works on the foundation that well oxygenated blood looks bright red compared to poorly oxygenated blood. The pulse oximeter consists of a flexible probe that is inserted in through the cervical os, comes to lie along side the baby's cheek, cheek of the face or the cheek of rearend if it happens to breech, and shines two lights into the flesh, the tissue. One is red light and the other one is infrared light. There's a photo detector that captures the light that's reflected back from the tissue and literally, the technology works by measuring the color of the blood in the fetal cheek. If it's bright red, relatively speaking, the oxygen level is high. If it's dark red, the oxygen level is low and the computer inside the pulse oximeter simply translates that relative redness, that relative color measurement into a number that is displayed on the front panel giving the obstetrical staff a clear and objective measure of the level of oxygen.
Van der Slikke:	So I understand this must be a different technique from the dual technique where you have a transmission from the pulse on the finger.
Swedlow:	Well, there are slight differences. The fetal environment is somewhat hostile for most electronics. It's dark, it's wet, it's difficult to see the patient; impossible to see the patient, I suppose and so the sensor has to be designed in such a way that its physical contact with the fetal skin is assured and there are various ways that that's done in the design of the sensor. There are two major differences really between conventional adult oximetry, when I say adult, I mean neonate's, adults, children, ex utero if you will, and fetal oximetry. In the vast majority of conventional oximeters, light is passed through tissue, it goes through the finger or across the nose, or through the ear or through the toes and the photo detector and light emitting diodes are on opposite sides of that tissue. That's the so-called transmissive pulse oximeter. In a fetal oximeter, there really is no convenient place to have fingers, toes or nose or ears, and so we've had to develop a reflectant technology which shines light into tissue and measures the back scattering, the reflection of light coming out of the tissue. The differences are really more technically interesting than clinically interesting and from a physics point of view, there really is no meaningful difference between transmissive and reflective. The same basic physics, the same basic technology works. One other significant difference however, is that because fetuses live at very low levels of oxygen saturation, their typical normal level is between 30% and 70% for example, instead of the normal ex utero person who is, let's say, 90-100%. We had to develop a different optical technology to deal with that much lower level of saturation, much more absorption of light at the low levels of saturation that are seen in the fetus. So we had to develop an optical wave length that would work and would be optimized for the level seen in the fetus, but the fundamental physics of how it works is virtually identical between conventional oximetry in an operating room, which has been around for 16 years and the fetal oximeter. There are small differences but they're really more technical than important.
Van der Slikke:	And we all know that the fetus has a different kind of hemoglobin, does that add something to -
Swedlow:	No, it does not. It turns out that although the fetus does have fetal hemoglobin and the adult typically has A2 hemoglobin unless they're sickler they hemoglobin F and hemoglobin S. It turns out that the color behavior, the color spectrum of adult hemoglobin and fetal hemoglobin are indistinguishable at the wavelengths that are used in oximetry, so the presence of fetal hemoglobin has no impact at all.
Van der Slikke:	In practice, I can imagine there are some technical problems to keep the sensor in the right position. Who wants to comment that?
Swedlow:	This is David again. I can give you sort of a technical description but I think the real tests are the experiences from the people who have used it. What we've done is to develop a sensor that has a flexible tip to it, which allows the lateral uterine wall to press the sensor against the fetal cheek, gently, in a non-traumatic way. The mechanical design of the sensor is such that it's very easy to insert through the cervical os and bring it alongside the cheek and this fulcrum or this soft flexible tip that protrudes out is caught by the uterine wall itself and serves as a fulcrum by which the sensor is gently pressed against the skin. There's also a set of electrical contacts on the fetal skin side of the sensor which tell the instrument and the user whether the sensor is in close physical contact with the fetal skin. If it is not, it's lifted up for some reason, the instrument will not read a value and it will alert the user that the sensor needs to be moved. Those are the technical issues, I think the experiential issues are really much more interesting here.
Van der Slikke:	Gary, you have a comment.
Dildy:	I think some people, first of all, are under the misimpression that the sensor is invasive or has some sort of an active attachment to the baby, but as Dr. Swedlow just described the sensor simply lies in contact with the face and as the baby's face is generally in very close contact with the maternal uterine wall or vaginal wall, the sensor simply is placed between the two and is held in by the natural pressures that are present during the labor process. Sensor placement itself is generally very straightforward. One has to take into consideration, by the pelvic examination what the position of the baby's head is, so the sensor can be placed across the temple or the cheek and with avoidance directly over the baby's face, and that's generally very easily determined by the pelvic exam during cervical evaluation. We also try to keep the sensor from being placed over a hair-bearing of the baby's scalp, if at all possible, because that can have an affect on the way the light shines between the light-emitting diodes and the photo detector. The sensor may require and very often in fact, does require adjustments during labor as the baby comes down the birth canal and as the baby's position changes during the labor process. And that's something that either a physician or a labor-delivery nurse or a midwife should be able to do after a very short period of time of training to place the sensor. By looking at the monitor, the monitor while giving you the oxygen saturation value also gives you indicators as to whether or not the actual detection of the baby's pulse and the baby's oxygen level is adequate to be interpreted. So you can tell by looking at the face of the monitor whether or not the signal that you're acquiring is adequate for interpretation. In fact, if the signal is not adequate, the computer automatically does not provide a readout for oxygen saturation and that would be one way of being aware that the sensor needs to be replaced into an appropriate position.
Van der Slikke:	The ease of the insertion is that comparable with the pressure line of the fetal monitoring? Is the easiness of insertion is comparable with inserting the pressure line of the monitor?
Dildy:	Actually, the entry of the pressure catheter advances further into the birth canal, than does the oxygen saturation monitor. But I think the techniques are fairly comparable.
Van der Slikke:	Are there some contraindications for using this method? Tom?
Garite:	I just wanted to add, before I answered that question, to Gary's answer that the learning curve for the individuals who have used it in our hospital has been remarkably short. The first few times you learn it, you do it, there is some technique adjustment that you have to learn but if you, after several patients, you're about as good as you're going to get, so it's quite remarkably adaptable to people already used to managing labor and electronic heart rate devices, so it's very user friendly in that respect. Please ask your second question again since I interrupted you.
Swedlow:	Contraindications.
Garite:	Oh, contraindications are really only technical right now. Certainly, you cannot use it until the membranes are ruptured. You cannot use it until the cervix is adequately dilated to place the sensor, so that's about two to three centimeters of dilation. You cannot use it until the baby's head is well enough descended into the pelvis so that you can have pressure against the face and that's probably about a minus one to minus two station, in that ballpark. Minus two would be a reasonable beginning point. You certainly can't use it on anybody that has a placenta previa but they're not going to have labor anyway, so that would be a silly contraindication to mention. Whether or not - we have added several contraindications in studies to play on the safe side, such as patients who are HIV positive or who have a great deal of vaginal bleeding or who are infected to begin with, but we don't know whether those are real contraindications or not. I doubt whether, honestly, there will be contraindications to this device that have any dissimilarities to contraindications for internal fetal heart rate and contraction monitoring. I can say that better. In other words, anybody who can have an internal electronic heart rate monitor and pressure catheter can probably have one of these. And I suspect as with any new technology, that the sensor is only going to get better. That it'll get smaller, it'll easier to apply and its contact with the baby is going to be easier to maintain, so that as these technologies improve, this is a baby technology, the latest sensor we've used is only a few years old or less and new sensors are being tried all the time so I suspect it's going to get better rather quickly.
Van der Slikke:	Yes, Gary.
Dildy:	It also remains to be seen but I do suspect that there might be some advantages to using this type of a system as opposed to a fetal scalp electrode which has to be introduced into the fetal scalp. For example, this could ultimately prove to be safer in situations where baby is Group B Strep positive or the mother has a history of genital herpes infection or a woman who has a history of HIV infection. Right now, we don't know if there are increased risks or actually benefits but theoretically speaking, I would think that the lack of invasiveness of this type of a monitor would be an advantage over a standard scalp electrode placement, and also scalp pH for that matter.
Van der Slikke:	Do you suggest that you could replace fetal heart rate monitoring by pulse oximetry?
Dildy:	In those particular situations, or in general?
Van der Slikke:	Well, both.
Dildy:	I would think in the specific situations for example, infection where in fact the electronic fetal heart rate tracing very often is abnormal appearing and very worrisome, this would be the ideal substitute or adjunct, perhaps better said, to assess fetal oxygenation. In situations where mothers have these other types of viral infections I would think, the way I feel about it, given the choice I would probably want to know the oxygen saturation without breaking the baby's skin, by using the pulse oximeter.
Van der Slikke:	Yes, Tom?
Garite:	You know, you've asked one of the key questions and it's been asked by virtually everybody I've talked to about fetal pulse oximetry and that's whether or not it will replace completely electronic heart rate monitoring. For the time being, the answer is no and one reason it won't is because you have to have ruptured membranes and an adequately dilated cervix. Electronic heart rate monitoring can be used through the maternal abdomen right now and at least right now, pulse oximetry cannot, though I heard rumors that even maybe someday we can do that, but that's not on the immediate horizon. The second reason that perhaps it won't replace heart rate monitoring is that heart rate monitoring is actually quite reliable when it's reassuring and it's already there. Everybody already has monitors, people know how to use it and it can tell you other things. For example, early infection will be indicated by tachycardia and we can determine heart rate with the pulse oximeter, so you could use the pulse oximeter and have a heart rate but it turns out that I believe that heart rate information is valuable. Secondly, one of the things that's very important is that electronic monitoring does one thing that pulse oximetry does not do. And that's it can tell you the mechanism of the fetal hypoxy, whereas with the pulse oximeter, it tells you whether the baby is well oxygenated, yes or no. However, with a variable deceleration, you know there's cord compression and that's the mechanism, in your interventions are going to be directly addressed at correcting cord compression if it's due to oligohydramnios we'll put some amniotic fluid back in with an amnio infusion. If it's due to descent of the fetus in the second stage, we'll alter the way and amount of pushes. If it's a late deceleration, we know that's a placental insufficiency problem and we'll look for reasons that the placenta's not well profused so that the pulse oximeter, I don't think can do that for us unless we turn the pulse oximeter into the sensor for the heart rate, which can be done. But we still need the heart rate data is what I'm saying.
Van der Slikke:	Thank you. We talked a lot about those clinical things but I want to end this discussion by talking about clinical trials that are being done and that have been done and are the results of those trials indeed showing things we want them to show? You understand it?
Swedlow:	Sure, this is David. Let me summarize the European experience and then turn to Tom and Gary for the US experience because they are much more intimately involved with it. In Europe, there are two major multicenter trials that have occurred, one in France, one in Germany. The French multicenter trial asks the question, could fetal pulse oximetry accurately and adequately substitute or replace for fetal blood scalp sampling for the determination of fetal acidosis. And the results were pretty clear and unequivocal that the answer was yes. Using a fetal pulse oximeter gave one the same kind of diagnostic accuracy of fetal acidosis as did a fetal blood sample and the general conclusion was that the fetal oximeter was substantially easier to use, less traumatic and equally reliable at diagnosing fetal acidosis compared with fetal blood scalp sampling. That's point number one. Point number two of the German's multicenter trial came to a similar conclusion in that they went a little further and tried to determine what was the critical threshold for fetal oxygen saturation, below which the fetus had a tendency to develop ongoing acidosis and above which the fetus did not develop fetal acidosis. In addition to confirming the diagnostic accuracy that the French trial showed, the German trial went a step further and demonstrated that that critical threshold was at a value of 30%, sort of the lower limit of normal from a population point of view and the critical threshold below which fetal acidosis continued to develop and actually continued to accumulate. So those two trials served in many ways as a for the protocol and the clinical trial that was setup here in the United States and I'll turn that over to Tom who's a principal investigator and Gary.
Garite:	Perhaps before I describe the ongoing trial, I'd ask Gary to give some of the background on some of the work that he's published because I think Gary's done work on what are normals, and some other work that also in addition to the French trials had set the stage for prospective randomized trial which I can describe.
Dildy:	We began work with the Nelcor Pulse Oximeter in late 1991 and initially, just assisted in performing observational studies to determine the feasibility of the technique and to look at what the saturation's were during normal labor and the cumulative results of studies performed at our center and other centers across the United States and Europe suggest that average oxygen saturation's were in the 40-50% range with low-normal around 30% and high-normal around 70. Over the course of time, the involvement that we've had has also allowed further research and development to improve the sensor and the software to attain more accurate and also more continuous signals to enhance the information that the clinician receives. So at this point in time, the monitor has developed to a stage where it's felt it is adequate for clinical usage.
Garite:	We began a large multicenter prospective clinical trial approximately three years ago. The trial-we were able to do the trials because of two major breakthroughs in my opinion, one is that the technology of the pulse oximeter came of age so that we could accurately obtain the data and obtain it for an adequate amount of time during labor that it was useful. The second was that we have confidence that this threshold value of 30% was indeed the correct value above which we were confident the baby was not acidotic and below which we were confident that it would not happen that often, that we would over intervene, but when it did happen, we had justification for other interventions which might be further assessment or actual cesarean section or operative vaginal delivery. Once we had confidence that we could do those things, then the question that we all agreed upon as being the question the study should answer was whether the adjunctive use, the addition of the pulse oximeter to conventional heart rate monitoring improved our ability to monitor the fetus such that we could reduce the necessity for operative intervention by cesarean section without harming any babies. And that's the crux. Can we intervene less often and not get any more bad babies. We don't want any bad babies, but we want the ability not to intervene so often and so we proposed a prospective randomized trial where we would treat half of the - or evaluate half of the patients in labor at term with fetal heart rate monitoring alone done traditionally as it is done in the vast majority of hospitals in this country versus another group where when the fetal heart rate monitor became concerning, we would add the pulse oximeter and use the pulse oximeter as the means of determining when we would have to intervene. Now we calculated that if the pulse oximeter allowed us to reduce cesarean section by 50%, that we would need 500 patients in each group to accomplish this study. Can I hold the tape for a minute? Did we do ten or eleven-we started with ten. We then began enrolling sites who would participate in the study and the study was done in three phases. The first phase actually helped us by just determining what the baseline likelihood of cesarean section was for non-reassuring fetal heart rate tracings and for dystocia where a non-reassuring heart rate tracing contributed to the decision. And we determined that that rate was about, I believe 11 or 12 % and then we were able to confirm that the numbers that we calculated were correct. We then went into a second phase where essentially we practiced doing the trial as it was designed, so that everybody would get good at placing the sensor, doing it right and doing the study right. Then once all the centers had done that, we went into the study phase, which we completed in November of 1998. We're now in the process of analyzing and collecting all the final data and within the next few months, we'll be doing the final analysis on that. I would like to sort of parenthetically point that I think is very important. I think that to the credit of the company, Nelco who developed this instrument, the opportunity was probably there for this instruments to be approved by the FDA even before this trial was embarked upon because they were very enthusiastic about it and the argument could have been made that had we just compared this modality with scalp pH which is the gold standard, probably could have gotten - I'm not sure, but they were very enthusiastic and possibly could have gotten it through. But to the credit of the company and because of some of the rather negative experiences that obstetrics has had with technologies like fetal heart rate monitoring, they wanted to see the correct prospective intervention trial done first, before this was put out on the general market. I am very excited and privileged to be involved with the company that has made a decision like that so that we can evaluate the tool properly before its introduced. That's not a commercial, it's just a result of my being involved with many clinical trials after the technology had already been imposed upon our patients and where it was too late to pull it back and this is the first such technology that I'm aware of in our specialty where the trials are being done right, before it's been introduced so…
Van der Slikke:	Any of you gentlemen want to add something on this discussion? I think we discussed why there is a need for technology like fetal pulse oximetry. We spent a lot of time with the technology and we had a very simple and very elegant technology that's used with it and then we have some of the results of the clinical experience and the stage where the clinical trials in the United States are in. Thank you very much gentlemen for your cooperation on this roundtable and I hope with you that within a very short time, we can use the technology for the benefit of the American women. Thank you all.