Medically Reviewed On: May 07, 2008

MARTY MOSS-COANE:  I'm Marty Moss-Coane.  If you're pregnant, and even if you're not, chances are you've heard of ultrasound, a diagnostic tool that produces pictures of the inside of the body using high-frequency sound waves.  But do you really know what doctors are looking for when they perform an ultrasound?  What kinds of abnormalities might they see?  And if something is wrong, what choices will you have to make?

Today on our webcast, we'll discuss the why, the when, the how of ultrasound.  Let me introduce our guests.  Dr. Unjera Jackson is a maternal/fetal medicine specialist and Director of Obstetrics at Morristown Memorial Hospital in Morristown, New Jersey.  Dr. Jackson, welcome.  Dr. Joan Atkin is a medical geneticist, and Director of Genetics at Atlantic Health System, in New Jersey.  Dr. Atkin, welcome to you as well.

Let me begin right with you, Dr. Atkin.  Help us understand a little bit more about ultrasound and how these high-frequency sound waves work.

JOAN ATKIN, MD:  That's exactly what they are.  It's like sonar, like what the bats use.  It is sound waves, and so there's no radiation, no exposure, and nothing that can harm the growing fetus inside.  But you bounce back sound waves and produce a picture on a screen.  Nowadays, we've gotten much better resolution, so the pictures are looking better and better, and even the parents looking at it can recognize parts of their fetus.

MARTY MOSS-COANE:  And they can actually see it on a screen.

JOAN ATKIN, MD:  They can, while we're doing it.

MARTY MOSS-COANE:  What is the actual gizmo, I guess; that's not a very medical term, that's used to get these pictures?  Dr. Jackson?

UNJERA JACKSON, MD:  The actually equipment is a relatively large machine that has a transducer attached to it.  The transducers are of various megahertz frequencies, depending upon the penetration that we wish to achieve in a particular case.  The waves are paced through the transducer, into the tissue and then back again, and the picture is then cast on the screen.

MARTY MOSS-COANE:  Is ultrasound used routinely in pregnancy?

UNJERA JACKSON, MD:  Ultrasounds are used almost routinely in pregnancy.  It is currently, in this country, not the standard of care that an ultrasound must be done in each and every pregnancy, and there are a variety of reasons for that, two of which include access to care or the technology, and another is cost.  There also are, even though very little information indicating that there's any risk whatsoever, that concern does come up also.  However, most obstetricians are offering at least one ultrasound to most of their patients, and aren't just using them for indications.

MARTY MOSS-COANE:  And offering them because it gives them important information on what?  About development, size of the fetus?

UNJERA JACKSON, MD:  There are a number of things that we look for, and it includes both the things that you mentioned and a variety of others.  Depending upon when the ultrasound is done, will determine what we can see and exactly what it is we're looking for.

First trimester ultrasounds are primarily done to determine viability, that is, is there a fetal heart? Is this a normal pregnancy?  Number of fetuses.  Some idea of where the placenta is implanted.  A look at the fluid around the baby.  The cervix, that is the mouth to the womb, of the uterus, as well as to look at the ovaries.  This is primarily what is confirmed at the time of a first-trimester ultrasound.

There are some sophisticated tests or, I should say, pieces of equipment, in some centers, where more information regarding anatomy may be obtained early in the first trimester.  But for the most part, the first trimester ultrasound is to obtain those basic criteria information that I first mentioned.

MARTY MOSS-COANE:  Do you want to do second trimester, and what can be found there?

JOAN ATKIN, MD:  The second trimester ultrasound is the one I'm most interested in, because that's how I examine my patient, which is the fetus.  At that time, and generally we recommend around 19 weeks' gestation, we can look very carefully at all of the organs that have been formed and are still growing and forming.  The idea of a second trimester, what we call targeted ultrasound, is to look very closely to see if there's any abnormalities present.  If there are abnormalities, that's when I become involved.  I try to put them together, as if it were an actual baby, and make a diagnosis.

MARTY MOSS-COANE:  When you talk about an abnormality in an ultrasound, is that something that you can see with your eye, or are you measuring certain organs or even the size of this fetus?

JOAN ATKIN, MD:  Absolutely both things.  What we can see that's not there.  For instance, there could be missing kidneys.  There could be a brain that hasn't developed well.  There could be a hole in the heart, congenital heart disease.  But also we're very concerned if the size of the fetus, usually we tell that by measuring the bones, the long bones and the size of the head and the size of the abdomen.  If that's much smaller than we expect, that's a very concerning thing as well.

MARTY MOSS-COANE:  And this is all information that an ultrasound, then, can give someone like a medical geneticist.

JOAN ATKIN, MD:  Yes, absolutely.

MARTY MOSS-COANE:  And for an obstetrician, you're looking for the same things?

UNJERA JACKSON, MD:  As an obstetrician, we are looking for the same things, but we are looking for additional things also.  We may be looking for abnormalities of the placenta.  For example, is it implanted too low down in the uterus, such that there could be complications such as bleeding during pregnancy?  Or the placenta may be situated such that it will interfere with a vaginal delivery, thereby placing that patient at risk or need for a Caesarean delivery.

We may be looking, as Dr. Atkin mentioned, at other abnormalities of fetal growth, not necessarily those that are a congenital problem, but just abnormalities of growth that could be related to maternal problems such as a hypertensive patient or a patient who has elevated blood pressures.  Or in a patient who may have been exposed to an infection early in pregnancy.  Or even later in pregnancy, there are certain things that we may find on the ultrasound.

MARTY MOSS-COANE:  I'm interested, too, in a third trimester ultrasound.  Are you looking for more of the same things or is there important information that's found only in the third trimester?

UNJERA JACKSON, MD:  I would say it's a continuum.  We are either confirming or finding additional information, compared to what we may have seen earlier.  And, in fact, for most of the growth abnormalities, unless it's something real significant and severe, it really doesn't show up until the third trimester.  You could have a normal second trimester screening ultrasound, and ultimately end up with a baby that has a growth abnormality.  Or even who may have a kidney or renal abnormality.  They don't necessarily all show up at a targeted second trimester ultrasound.  However, this is still the single most important time, if you're going to do a screening ultrasound, to perform that test.  That is, between about 18 and 20 weeks gestation.

MARTY MOSS-COANE:  What about third trimester for you?

JOAN ATKIN, MD:  The reason that we like to do an ultrasound in second trimester is so that, if we find an abnormality, we can do more testing.  If there turns out to be a very significant abnormality, especially those that are incompatible with life, the couple would have a choice of whether to continue the pregnancy or not.

Usually third trimester ultrasounds are done when there's a significant problem that's been picked up before and needs to be followed, or something on the obstetrical exam that makes the doctor suspicious of a problem.  So third trimester is not done routinely.

MARTY MOSS-COANE:  I'm wondering, too, what options.  Let's say you do finds some kinds of problems.  What other testing options might be available to you and the patient?  Dr. Atkin?

JOAN ATKIN, MD:  One of the things we do, depending on what we find, is to continue to do what we call serial ultrasounds.  For instance, I'll give an example of where we find some problem with one of the kidneys.  What we need to find out is if those kidneys are making urine.  So we need to continue to follow the pregnancy to see if that becomes a problem.

Another thing that we do is what we call a fetal echocardiogram.  It's a specialized ultrasound of the heart, to see if there's an anatomic abnormality of the heart.  We've gotten really good at this, and we can pick up most of the congenital heart defects from a fetus in second trimester.

The third thing that we do is offer amniocentesis.  That's the procedure where we can take out some amniotic fluid where there are fetal cells, and we can analyze those to see if there might be a chromosomal abnormality that could result in a major problem for a baby.

UNJERA JACKSON, MD:  And occasionally, particularly when there is a late pickup, and we really want to get an answer rapidly, and sometimes there may be abnormalities of amniotic fluid volume, so that there could be too little or too much.  But particularly in cases where there's too little and we're suspicious of something chromosomal going on, there are some other, more invasive tests that may be done.

A placental biopsy can be done, which is a variation of a chorionic villus sampling, but done later in pregnancy, as well as umbilical cord blood sampling, known as PUBS, percutaneous umbilical blood sampling.

MARTY MOSS-COANE:  Is it possible, then, to fix some of these problems?  You mentioned that there might be a little heart problem for this child.  Is it possible to fix the problem in utero?

JOAN ATKIN, MD:  That would be great.  We haven't gotten to fixing congenital heart defects before a baby is born.  There are some centers in the country, in the world, that are trying to do prenatal surgery, where they actually take the fetus out of the womb and try to fix something.  For instance, again, a blockage from the kidney, and then put the fetus back in, and sew up the uterus, and hope the pregnancy continues to term.

Obviously you can figure out that there's a lot of hazards with that, and so it's very rarely done.  But it is possible with some things, and we're hoping to continue to do research in that area, and find out more and more ways where we might be able to help a pregnancy where the fetus has a problem, before the baby is born.

MARTY MOSS-COANE:  What kind of relationship do you like to have with your patients?  You're working with them over time, you're working with them in this important time in their life, and especially if there's some kind of problem that develops.  Do you want them to be your partner in this, your teammate in this?

UNJERA JACKSON, MD:  I think it really has to be that way.  We don't make decisions for patients.  We provide them with information to help them make well-informed, intelligent decisions, and then we support them in what their decisions are.  We believe in the team approach.  That is, when there is a problem and the pregnancy is being continued, we have all the pertinent subspecialists, as Dr. Atkin has previously mentioned, become involved.

Such as, if there's a heart lesion, the cardiologist as well as the cardiac surgeon.  If there's a problem with the spine, possibly a neurosurgeon.  So, yes, it's a team approach, and we are partners in this.

MARTY MOSS-COANE:  I'm sure for couples it can be so overwhelming, and there must be times when they just really don't know where to turn.  A very difficult time, when they have to make some very important decisions.  How do you help them?

JOAN ATKIN, MD:  That's really true, and we do end up having a very time consumption type of specialty, where we spend a lot of time with the patients.  Some of it's just moral support.  And a lot of it's informational.  Some of my patients actually need to go see other people for therapeutic counseling.  They need to work through their decision-making.  Sometimes there are couples that don't agree on how they want to handle a problem, and that can be very difficult.  Those are couples that really need a lot of extra counseling.

Sometimes we have couples that have extraordinary circumstances in their lives besides this problem, and they really need a lot of help and support.  I make myself available at all hours.  I spend a lot of time with them, and I refer them to other counselors and therapists if they need it.

MARTY MOSS-COANE:  Do you find that patients come in knowing about things like amniocentesis and knowing about ultrasound?  Do you find that the patient population is more informed than they used to be?

UNJERA JACKSON, MD:  I think they are much more informed.  They certainly are aware.  However, they don't have all the information.  For example, as you mentioned in the opening statement, they have heard of it, but they really don't know the limitations.  For example, that a normal ultrasound and normal chromosomes do not necessarily guarantee normal outcome.  And it's really important during the counseling for us to make it clear that we have ruled out what we can rule out based on the limitations of the studies that we have available to us.

MARTY MOSS-COANE:  You want to add to that, Dr. Atkin?

JOAN ATKIN, MD:  That's exactly right.  There's a lot of information they have.  There's a lot in most of the magazines out there.  There's certainly a lot on the internet.

MARTY MOSS-COANE:  Yes, I saw you roll your eyes when you said that, too.

JOAN ATKIN, MD:  They do get a lot of information on the internet, and many times it's very helpful that they're educated.  Sometimes they get wrong information in places, and we need to reeducate them.  But I would say in general they have a lot more information than they did 10 years ago or 20 years ago.

MARTY MOSS-COANE:  Is it possible to overuse ultrasound?

UNJERA JACKSON, MD:  I think it's possible to overuse any technology that's available.  There certainly are many patients who require serial ultrasounds for a variety of reasons, and we have to do them.  Many times, though, we have patients who have no risk factors, who want to have an ultrasound, because they want to know the sex of the baby, or they want a better idea of how much the baby weighs.  And when there are clinical indications to have an ultrasound, when we can determine what the sex is based on the ultrasound, then that's an added bonus, but that should not be an indication for obtaining an ultrasound.

MARTY MOSS-COANE:  And there's no guarantee you can figure out the sex, right?

UNJERA JACKSON, MD:  There's no guarantee, but if the baby is in the right position, with the high-resolution equipment that we have, we can, we're pretty good at being able to determine what the sex is by ultrasound.

MARTY MOSS-COANE:  Do you think it's possible to overuse ultrasound?

JOAN ATKIN, MD:  Like Dr. Jackson said, anything's possible.  We tend to not overuse ultrasound, because we want to use it for what it's needed for.  We want to be able to use the resources that we have for the patients that need it.  I don't think that there's a danger associated with using ultrasound, but there really isn't any reason in most normal pregnancies to have more than one or two ultrasounds, depending on the situation.  There really isn't a reason to do it every week or every month, unless there's a problem.

MARTY MOSS-COANE:  But I'm sure for patients who want information, and we have the technology, and it's safe, you want to know as much as you possibly can about what's happening with this developing child.

UNJERA JACKSON, MD:  I think that's true, but at the same time, we have to use some reasonable medical judgment as well in determining who actually gets the ultrasound and when the ultrasounds are performed.  I think a bigger danger, actually, is ultrasounds being performed in a situation where it is not fully a targeted ultrasound and there is the chance of missing something that could be picked up.  So it is really important to know where the ultrasounds are being performed and who's performing them.  They really should be in centers were maternal/fetal medicine specialists are extremely qualified radiologists, who have the experience in maternal/fetal medicine to be able to interpret the finding appropriately.

MARTY MOSS-COANE:  We are going to end on that note, and I thank you both very much for joining us today.  Thank you.  And thank you for joining us as well.  I'm Marty Moss-Coane.