Joshua A. Copel, MD

,       and I’ve managed to find Beryl Benacerraf as she’s leaving for the       plane to ask her a question submitted by e-mail.        Beryl, the question here is when we use markers in trisomy 21       during the second trimester and when nuchal translucency during the first       trimester and triple screen markers are normal, can we consider these       markers to be independent?  Can       we use a Bayes theorem approach to create a new maternal risk after the       first tests that are different from the maternal second trimester age       related risks?”

:        “Actually, I don’t know the answer to that question.        I think there is a study going on right now in the United States,       which is trying to answer that question, but I think that it’s possible       that we can lower that risk.  I       think the markers in the first trimester and the markers in the second       trimester, and particularly, the ultrasound markers are probably       independent of each other, other than the nuchal fold.        Probably the best approach is to use both gestational ages instead       of markers in order to have a complete assessment of the risk.”

:        “The question sounds very much like the paper by Nick Wald in the       New England Journal of Medicine over the summer of 1999 which made the       assumption that all the markers were independent but we can’t assume       that till it’s been studied such as in the study that you’ve just       mentioned.  Wouldn’t you       agree?”

:        “Yes, I agree.  I think the study that I’ve just mentioned whose name       escapes me right now but…”

:        “It’s either the FASTER Trial or the FIRST Trial.”

:        “Yes, the FASTER Trial, I think that will be a very       important study for a lot of different reasons.        It may change the way that we approach prenatal screening for       chromosomal abnormalities in the future.”

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OBGYN.net Conference CoverageINTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY:Zagreb, Croatia

Prenatal Testing

:        “This is Josh Copel and I’m now going to be       interviewing Professor Stuart Campbell, the immediate past President of       the International Society of Ultrasound in Obstetrics and Gynecology.        At this point, we’re about at the halfway point of the meeting;       it’s late morning on Friday so we haven’t heard everything but I’m       wondering if you can share with us what your impressions are so far about       new and exciting things that we’ve heard about this year.”

:        “I think the thing that’s impressing me is the       development of new technologies especially three-dimensional ultrasound       and the ability to depict fetal anatomy especially in the first trimester.        What also impresses me is that prenatal diagnosis is going to move       from the classical time in gestation of 20-22 weeks to the first trimester       of around 10-14 weeks.  I’ve       just seen the most wonderful presentation by Bernard Benoit from Nice in France where he was able to show the development       of the fetal brain from six weeks right through to fourteen weeks and show       abnormalities of the brain occurring at that period of gestation.        I think this is a real pointer for the future and 3-D ultrasound       has also been invaluable in gynecology in showing congenital abnormalities       of the uterus and also in showing profusion of organs and the amount of       flow in organs in a volume scan so that you can get an overall assessment       of how much flow is going to that organ which I think is a big advance       over the classical way of picking out an individual vessel and looking at       its resistance or velocity.  So       there are many exciting developments going on and continuing to go on in       ultrasound but I do think the developments of first trimester diagnosis       are really landmark papers and will take us on well into this century.”

:        “Last night some of us heard a presentation at an ATL       event from Larry Platt in showing some of their new technology.        Do you think we need to rewrite the textbooks now in terms of what       we can see and when, and will we be pushing things that much earlier that       we need to redefine what’s normal anatomy as well?”

:        “Yes, I think so.  The important thing, of course, is that in the first       trimester this is a period of organogenesis, the brain is developing       embryologically so what you can see at that gestation might seem abnormal       in terms of the host embryonic developments.        One has to be very, very careful and truly understand the normal       developmental anatomy and that, of course, goes for other structures as       well, such as the bowel.  So       while we’re very excited at the potential for early prenatal diagnosis,       one has to be cautious and make sure that we get the embryology right.”

New Developments in Obstetrical Ultrasound

:        “Hi, I’m interviewing Dr. Lachlan De Crespigny who is well       known in ultrasound for many years.  After       we spent the last couple of weeks in joining the views from Sydney on       worldwide television, we will be following in the steps of the Olympics       and taking the 11

 World Congress of Ultrasound in Obstetrics       and Gynecology to Melbourne, Australia that’s a little bit different       from Sydney.  I’d like to ask you how is       it different and what can we look forward to?”

:        “Mostly, we can look forward to the scientific program       which we hope we will bring in some innovations to allow the audience more       participation in the program by meeting many of the lecturers, the latest       speakers, and by having lunch sessions with the latest speakers and       audience electronic voting.  Clearly, they can feel very much involved in it but as you       said as well, we have to ride on the back of the Olympics in that I think       the people have now seen much of the wonderful environment that Australia       has to offer and the people will take it as an opportunity to extend this       to be a holiday as well.”

:        “Will there be hands-on scanning available for the participants       at this meeting?”

:  “We       want to emphasize live scanning and the manufacturers as well are very       keen to have that to expose their machines, and many of our people in       Australia and I know elsewhere want to see the expert scanning.        With live scanning we probably wouldn’t do too much of that but       with the size of meeting we’ll have, it’s difficult to give individual       hands-on in any meaningful way.”

:        “How large of a meeting are you anticipating?”

:  “We’re       expecting 1,500 people.  What’s       interesting is a lot of people think that Europeans and people from North       America won’t come to Australia for meetings but, in fact, the track       record is very different.  The       Menopause Association met recently and the World IVF meeting and they have       had half or as many as double the number of registrants they’ve had in       the European meetings.  This is a trend and I think it’s for two reasons, firstly,       Australians are very good attenders of meetings, they’re very       enthusiastic learners, and also people do want to come to Australia and       that has been the case recently.  So       we believe 1,500 people is very realistic and that’s what we’re       telling our trade representatives.”

:        “Tell me a little bit more about the ‘Meet the Professor       Lunches.’  How large will       those be and what sort of topics would you anticipate?”

:  “The       topics would tend to be what the speaker is addressing at the meeting.  There will be an informal gathering, lunch will be provided       there, there will be no lecture, and there’ll be an opportunity for       15-20 people to explore issues in depth.        I particularly and I think many others like to have an opportunity       to speak ones own mind

and this       is very close to that so that you can have really in depth discussion and       get to know the professors.”

:        “So it will be a no holds barred open season on the speakers?”

:        “Yes, that’s right and I hope it will be just that.        There’s some people that can really quiz them and put them under       pressure in a way that it can be more difficult to do in a larger       forum.”

:        “I always find those sessions to be a lot of fun on the       receiving end, and I’ll be looking forward to that as well.        Thank you very much for your time, and we’ll look forward to       seeing you.”

11th World Congress of Ultrasound in Obstetrics and Gynecology

:  “I’m       with David Nyberg who is part of 

,       and I have a couple of questions that were sent in by other list readers       for you, David, here at ISUOG.  The       first question is about the use of markers in trisomy 21 during the second       trimester when the nuchal translucency during the first trimester and the       triple markers are normal.  Are       these things independent and are there any ways we can apply Bayes theorem       to get a new maternal risk after the first two tests that are different       from the second trimester age related risks?”

:        “That’s a very good question.        I think it’s potentially quite dangerous to try to apply       sequential screening, which is what the question is proposing.        I think the current tests really are best done as an integrated or       simultaneous test.  Whenever       you have an a prior test it changes the prevalence of the disease       considerably based on the sensitivity of the prior test, so you have to       adjust accordingly.  The kinds       of likelihood ratios and risks we’re talking about with second trimester       ultrasound clearly aren’t true when there’s already been a prior scan       that is normal.  The second trimester biochemistry and the first trimester       biochemistry seems to be independent of the ultrasound findings at least       in normal fetuses, so in those cases we should consider the biochemistry       and include it in our combined risk.        We can do that easily for the second trimester and certainly Wald       has proposed ways of combining that for the first and second trimester,       and I think there will be a variety of ways of doing that.        But that’s still a single kind of combined risk estimate and if       you have a prior test like nuchal translucency and it has a high       sensitivity and it’s been applied to that population, we really have to       reduce the prevalence of the disease by the sensitivity.”

:        “I know it’s a hard question to answer because earlier       this morning I interviewed Beryl Benacerraf with the same question and she       also was unable to come up with a clear answer because of that difficulty       and that’s something that certainly needs to be studied.        The other question that came in that was specifically addressed to       you was about the pick-up rate of ectopics.        What can you say about our pick-up rate of ectopics with first       trimester ultrasound, I guess to rephrase the question, when you’re       doing first trimester scans in women who aren’t presenting with       symptoms, do you have any sense of what the sensitivity or detection rate       of ectopics is in that population?”

:        “That’s another very good question, and I think the answer will       depend on the population and particularly on how early you are examining       that patient.  In infertility       patients where we’re looking very early, the pick-up rates going to be       less on a single ultrasound examination.        On the other hand, I think when we talk about detection rates we       should think about what’s our detection rate over maybe not a single       exam but over a three day period of time.        After all, the average delay in diagnosis of ectopic pregnancy used       to be in the order of two weeks after the onset of clinical symptoms.        Now we’re clearly detecting ectopic pregnancies earlier, and I       don’t think we need to expect to detect them all, particularly, for       asymptomatic patients on a single day but I think over the course of three       days with the follow up of HCG and/or       ultrasound, we should be able to detect them well over 90%.        On a single exam early in pregnancy, again, it’s a complicated       answer and it depends entirely on the gestational age that we see them and       the viability of that particular patient population so that’s a little       hard to answer but I would say it’s probably less than 50% nowadays       simply because we’re asked to see these patients earlier and before they       have symptoms.”

:        “Thank you and thank you for your time.”