Transvaginal Anatomy Scan

September 15, 2006

OBGYN.net Conference CoverageFrom AIUM 44th Conference held in San Francisco, California - April, 2000

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Martin Necas, RDMS, RVT: "Hi, I’m Martin Necas the Ultrasound Coordinator for OBGYN.net. I’m here at the 44th Annual Convention in San Francisco and sitting with me is Dr. Timor-Tritsch who is from the New York University Medical Center. He has been giving presentations here at the conference, and one particular topic that I found of interest was his discussion about 14 week transvaginal anatomy scans. I was wondering if you could give us a little bit of an overview about this technique and how you find it in daily practice?"

Dr. Ilan Timor-Tritsch: "It really is a 14-16 week transvaginal scan and the prerequisite for it is to have a reasonably good high frequency machine or a transvaginal probe and the knowledge of anatomy at that gestational age. What it entails is checking the fetus from head to toe and from inside to outside. There are lots of advantages to it because first of all the high frequency vaginal probe can encompass the entire fetus at that gestational age so it gives you a very high resolution picture. The other advantage is that the fetus is mobile at that time, most spontaneously or slightly helped by the abdominally placed second hand of the operator so you can really change and get into focus all the organs and organ systems that you need. Basically, it was pioneered in Israel and immediately followed by some operators in the Netherlands, Denmark, and in Germany, and once again, as you have heard in my presentation, unfortunately does not penetrate the USA obstetric and gynecologic community."

Martin Necas, RDMS, RVT: "What do you think is the source of this reluctance on the part of the American sonography or sonologists community to pick up this technique and make it a part of the routine intranatal care?"

Dr. Ilan Timor-Tritsch: "There are several ingredients to this hesitancy of the United States to this technique, and I will go through them real quick because as you heard it was almost a 30-minute lecture. First of all, is the fact that there are no good outcome studies published in the American literature. That also carries a very severe critique of mine of the American journal editors who were unable to overcome some of their personal opinions and rejected most of the articles that were submitted even on a large number of these patients done outside the United States. The second reason would be that most of the studies are published in foreign journals and even though they are in English, they are published in journals that the American obstetric and gynecologic community does not read or not journals that everybody reads. The third ingredient would be that in the United States, unfortunately, the routine scans of a pregnant patient are still debated and still not customary. Although there is a lot of improvement and every excuse is used by the patients and by the doctors to get the scan, I still don’t think that more than 50%-60% of the patients are scanned in the United States in pregnancy. The other reason would be that managed care wouldn’t reimburse it, and obviously many of the American obstetrician-gynecologists will not work unless compensated. And indeed, some of the people at the conference asked me whether these are lengthy scans or not and they are. As a matter of fact, they are at least a 20-30 minute investment from the part of the physician or the sonographer so basically, these would be the major reasons. But there are some minor reasons – pregnant American women are not sufficiently informed either by self-education or by their obstetricians. Maybe they are not connected to the Internet to see sites such as this one for a good example, and therefore, the interest is somewhat less than I see in Europe and in Israel where I know the situation really well because some of the Israeli operators were my pupils, so I know exactly how it is. For instance, in Europe and in Israel, women do not go for a scan with a referral slip from their doctors. They just call up the doctor and say - I would like to have a scan. How come they know that the scan is available? So here is the difference between the American pregnant patient and the European or the Israeli pregnant patient. Here in the United States you have to have a referral slip, and once again, the obstetrician may not want to give that referral slip or does not even know that this modality exists. So here in a nutshell are some of the reasons that I see as a problem here in the United States."

Martin Necas, RDMS, RVT: "I see, do you think that as the attitudes towards transvaginal anatomy scans change amongst the professional community as well as patients that the scan can actually replace the routine anatomy scans that we’re doing today at a later gestational age?"

Dr. Ilan Timor-Tritsch: "Here is the misconception that most of the obstetricians and probably some of the representatives of the governing bodies think in general the technique is pushing to replace or to eliminate the later transabdominal scan. This is absolutely a misconception because this early anatomy scan which probably detects 85% of the malformations or probably even a little more will not push out or replace the transabdominal scan which is done slightly later at around 20-22 weeks which should really be a complimentary scan. Together they should render a 90%-95% detection rate so both have to be done in order to yield a very high confident limit or confident to the pregnant patient."

Martin Necas, RDMS, RVT: "How does nuchal translucency screening fit into this picture? If we were to perform a routine nuchal translucency, say, from 10 weeks onwards, then a transvaginal anatomy scan at 14-16 weeks, do we then repeat an anatomy scan at a later gestational age? It seems that there will be limits to the sonographer resources."

Dr. Ilan Timor-Tritsch: "This is an extremely important question, and I have two answers to this and I’ll give you both of my answers. First of all, what is wrong with scanning a pregnant patient three times? As a matter of fact, if I have a suspicion that I have a heart problem, I will go to my internist once, twice, three times, twelve times - as many times as I need to clarify the situation. What is wrong with scanning that pregnant patient three times in the first part of the pregnancy? As far as I’m concerned, this is an investment for the next seventy or ninety years for that person who is just about to come into the world. So this is one answer, and of course, you will also have to substantiate this with resources and you said there may not be the amount of machines, sonographers, sonologists, facilities, or machines available to do this. But then there is another compromise that I see coming up - machines are becoming increasingly better and yielding higher resolutions. So maybe the nuchal translucency scan which is done up to 14 weeks we can have a compromise by doing that vaginal structural evaluation close to or at 14 weeks with a good machine including nuchal translucency and then pushing out the limit of the second scan to about 20 or 22 weeks when the confirmatory transabdominal scan can be done. I see this coming because even now we have at least one or two true top of the line machines with transvaginal but also with transabdominal transducers that can do a good job at 14 weeks so maybe that will be a compromise. But once again, I see absolutely nothing wrong with a pregnant patient who would like to invest the time and maybe the money to get three scans in pregnancy. As a matter of fact, if you would ask me, and you didn’t, whether I believe in the fourth scan, I will tell you that I would like to have another scan at around 7 weeks to make sure that there is not an ectopic pregnancy at the very beginning or not a non-developing early embryonic demise which is 10% at that gestational age. So I would be in favor of four scans in a pregnancy, and of course, the fifth one at around 28-32 weeks for a growth scan so this would be my agenda for money really well spent maybe in a package for a pregnant patient."

Martin Necas, RDMS, RVT: "Dr. Timor-Tritsch, I would like to thank you for the interview and for giving us a bit of a perspective on the transvaginal anatomy scan and a little bit of an overview of perhaps what we should expect in the future. Thank you very much."

Dr. Ilan Timor-Tritsch: "Thank you."