|
||||||||
|
|
|
From XVII European Congress on Perinatal Medicine, Porto, Portugal-June 2000 Multiple Pregnancy after ART: The Importance of an Early DiagnosisHugo C. Verhoeven MD, OBGYN.net Editorial Advisor interviews Dr. Alexandra Matias, Assistant Professor at the Department of Obstetrics and Gynecology at Porto University Audio/Video Link *requires RealPlayer - free download Dr.
Hugo Verhoeven:
“My name is Hugo Verhoeven, I’m from the Center for
Reproductive Medicine in Dusseldorf, Germany, and I’m reporting from the
European Congress on Perinatal Medicine in Porto. It is an exceptional honor for me talking now with Dr.
Alexandra Matias who is a Specialist in Obstetrics and Gynecology at S.
Joao Hospital in Porto and also Assistant Professor at the Faculty of
Medicine at the University of Porto.
Dr. Matias, thank you very much for giving me the chance to talk to
you. Yesterday, I heard two
of your lectures and I have the feeling that you are one of the coming
stars in the field of obstetrical problems of multiples.
Yesterday, we discussed the worldwide exploding incidence of
multiples. One major reason for that is that artificial reproductive
technologies are increasingly successful so that in the last ten years we
see Dr.
Alexandra Matias:
“Whenever there is a discrepancy between the gestational age
estimated by the last menses period and fundal height, when two
differently located fetal heart sounds are detected, or when hCG plasma
levels are higher than expected, an ultrasound examination is mandatory as
early as possible. The 10-14
weeks’ scan is the best targeted ultrasound because in this scan there
are several questions that can be promptly answered; the first is the
number of embryos or fetuses and the chorionicity.” Dr.
Hugo Verhoeven:
“What is chorionicity?” Dr.
Alexandra Matias:
“Chorionicity stands for the type of placentation and this is a
very important issue because chorionicity is a significant factor, that
will influence the perinatal course. The reality of expecting two babies
with two placentas or two babies with one placenta is completely
different, involving specific medical problems in the future. This
information about the type of placentation is very important for the
doctor in charge of a pregnant woman carrying multiples to know what kind
of pregnancy he is dealing with. So
it’s mandatory to define the number of embryos/fetuses and chorionicity.
Secondly, it’s very important to assess the gestational age:
sometimes the ladies aren’t sure about the last menstrual period, they
have been taking the pill for the last three months, contributing to an
unreliable gestational age. Therefore,
it is of paramount importance to assess the correct gestational age, to
know exactly how many weeks we’ll have at the end when we want to
terminate a pregnancy or when the delivery will spontaneously occur.
Another important issue, not only concerning singletons but also
multiples, is the screening of aneuploidies.” Dr.
Hugo Verhoeven:
“What is that?” Dr.
Alexandra Matias:
“Aneuploidies are chromosomal abnormalities. The most frequent
aneuploidy is Down’s syndrome or mongolism. When the karyotype of a
fetus is abnormal, the parents should be informed in order to decide what
to do with this pregnancy. One of the possibilities for assessing this
risk is to measure nuchal translucency. Nuchal translucency is the fluid
that accumulates behind the fetal neck and which thickness is measured by
ultrasound between ten and fourteen weeks gestation.
In the case of a monochorionic twin pregnancy, nuchal translucency
can be also used for screening of an early onset hemodynamic overload. If
nuchal translucency is increased in one of the fetuses and discrepant
between the two, this can be the first sign of hemodynamic imbalance that
will later be translated as a twin-to-twin transfusion syndrome. The donor will transfuse blood to the recipient and this
“flood” will have consequences - cardiac consequences, neurological
consequences. Therefore in order to avoid such sequelae
it is of importance to screen for this hemodynamic problem.
Summing up, I think it’s very important in multiples to perform a
scan between 10-14 week gestation in order to assess the gestational age,
to define chorionicity and the number of fetuses involved, to screen for
aneuploidies, and in the case of monochorionic twin pregnancies, to have a
first clue about the hemodynamic behavior of those fetuses early in
pregnancy.” Dr.
Hugo Verhoeven:
“This brings us immediately to the next very important thing.
If you have the suspicion that something’s going wrong and you
think there could be a chromosomal anomaly or you have a suspicion there
is the beginning of a transfusion syndrome between the two babies, what do
you do?” Dr.
Alexandra Matias:
“In the first case if an abnormal karyotype is suspected, of
course, we should inform the couple that after a positive screening test
the only possibility of being sure about the karyotype is to perform a
diagnostic test, that is, an invasive procedure must be done.
Depending on the experience of the centers around the world on what
is routinely performed in each hospital (either amniocentesis or chorionic
villus sampling, by the transvaginal and transabdominal approach), and the
time needed for a confident answer from the cytogenetic lab, the
appropriate invasive test will be selected to obtain the karyotype as soon
as possible. Dr.
Hugo Verhoeven:
“So the difference between the two is that you can take a little
part of the placenta to do an analysis or you’re taking out a little bit
of amniotic fluid. What about difficulties in performing amniocentesis ,
singletons compared with quintiplets ? Dr.
Alexandra Matias:
“Clearly to perform an amniocentesis in a singleton pregnancy is
a much more straightforward procedure. To accomplish it in multiples is
much more complicated. Highly
skilled operators are needed. The decision of which one of the invasive
procedures should be chosen in the case of multiples depends mostly on the
type of chorionicity, on the experience and technical skills of the
center, on the gestational age, on the position of the fetuses. The risks inherent to invasive tests such as fetal
demise or premature delivery are less than 1% in experienced hands – the
risks for both singletons and multiples are about the same.” Dr.
Hugo Verhoeven:
“How do you know that each time you’re in another sac and that
you’re not aspirating the same sac two or three times so that you are
maybe missing one of the sacs which has the chromosomal anomaly?
Dr.
Alexandra Matias:
“The risk of sampling twice the same fetus and of not having
information about the other fetus exists but there are some tricks to
identify each of the sacs. One of them would be to use dyes
like indigo carmine. Another technique is to use bubbles exiting the
needle to assess in which of the sacs the operator is in. Another
possibility is the “one-shot” technique where the fluid is aspirated
from the closest sac and then the syringe is advanced to sample the most
distant sac. If the two gestational sacs are clearly differently located,
for example one on the right side and one on the left side of uterus, one
can go first to one sac and then to the opposite side to sample the other
sac. So there are different
techniques but, unfortunately, we cannot be absolutely sure that we have
sampled each sac, each baby.” Dr.
Hugo Verhoeven:
“We do an aspiration of amniotic fluid and find a chromosomal
anomaly, we have to do something. We have quintuplets or triplets and one
of the babies has a Down’s syndrome. Tell me what can happen or what the treatment could be and
what would be the consequence for the, let’s call them, the survivors,
what is the risk for them?” Dr.
Alexandra Matias:
“Again, it depends on the legal policies of the country and on
what the parents want to do about this pregnancy and about this baby.
Let’s say that they’d like to terminate this pregnancy and that
the termination is allowed in their country.
Termination of pregnancy can be done with potassium chloride, for
example, to stop the heart of the baby from beating. But before performing
the procedure chorionicity must be known and checked.
If one is dealing with a dichorionic pregnancy, the termination of
the affected twin will be harmless for the co-twin.
In the case of a monochorionic twin pregnancy, the demise of one of
the twins can cause serious morbidity to the surviving co-twin due to the
transfer through superficial anasthomoses of blood from the baby that is
alive to the baby that was terminated. The survivor will exsanguinate to
the dead fetus and neurological sequellae will eventually arise due to an
abrupt hypotension. Polycystic encephalomalacia, porencephalic cysts and
cerebral palsy in the survivor are some examples of the neurological
impairment consequent to the intrauterine death of a co-twin.” Dr.
Hugo Verhoeven:
“So that would be the treatment of a medical situation; you have
a malformation so you must do something.
Now we also have the problem of the elective reduction because the
patient doesn’t want to have triplets or because you think that the lady
is not able to carry triplets till the end of pregnancy because of medical
reasons and so you have to do an elective reduction.
Do you have some special thoughts about that?” Dr.
Alexandra Matias:
“I think that in most instances the discussion about multiples
should begin much earlier than elective termination. People dealing with
iatrogenic multiples should think how many embryos could or should be
transferred. For example, I
know from your talk Dr.
Hugo Verhoeven:
“But let us say you
already have the multiple, in the 10th week you find triplets, even if you
did the transfer of only two embryos this can happen.
The patient says - I don’t want that, what is your policy?” Dr.
Alexandra Matias:
“In my country the reduction of multiples without major problems
(lethal malformations or abnormal karyotype) is not allowed.
However, there are countries like the United States and Israel
where elective termination of high order multiple pregnancies is safely
undertaken until 16 weeks gestation with high rates of success.
After that period it can be very problematic because the risks of
premature delivery increase exponentially and because for the parents, I
think, the bereavement is worse. So
the best experience is to terminate these high order multiple pregnancies
until 16 weeks.” Dr.
Hugo Verhoeven:
“My final question is always the same - what do you expect from
the future, what are your dreams, what do you expect bettering your
professional life?” Dr.
Alexandra Matias:
“First of all, I would like to come back to the first point of
our talk. We can deliver a better service to multiple gestation parents if
we can offer an early scan at 10-14 weeks, so that the parents know what
they can expect from this pregnancy – how many multiples are expected,
what kind of multiples are coming, and what are the medical problems
associated with this kind of twins. Secondly,
I think that the neonatologists have come to a plateau in the care they
can offer to very low birth weight infants. We have not made important steps forward in the last years
and the limit of viability is still 24-25 weeks around the world. I think
that if such panorama remains unchanged, we should continue to be very
careful about high order multiple pregnancies due to the ongoing problems
in dealing with severe prematurity. This
is really a very important point. If these babies are born prematurely,
they’ll be more prone to future handicaps like cerebral palsy or lung
hypoplasia, and they’ll be a major burden, familial burden, social
burden, and psychological burden to this family and to the coexisting
children. I think that the
ball is now in the field of obstetricians, since the neonatologists are
already doing as much as they can. So let’s know from the very beginning what kind of
multiples are we expecting in order to offer the best of our services to
multiple gestations.” Dr.
Hugo Verhoeven:
“Perfect, Alexandra, thank you very much.” Dr.
Alexandra Matias:
“It was my pleasure.” courtesy of OBGYN.net |
|
| OBLink.com © 2002-2009 Ferring Pharmaceuticals, All Rights Reserved. |
