OBSTET-L Mensagens pela Março, 2001: Re: trabalhos interessantes VIII

Re: trabalhos interessantes VIII

From: João Batista Marinho de Castro Lima

jbmclima@uol.com.br

Sun, 11 Mar 2001 17:28:29 -0300

João Batista Marinho de Castro Lima R. Jussara no. 304 apto. 202 31.140-070 Bairro da Graça Belo Horizonte - MG

>----- Original Message -----
From: "Thomaz Rafael Gollop" <trgollop@usp.br> To: "Multiple recipients of list OBSTET-L" <obstet-l@mail.medispecialty.com> Sent: Sunday, March 11, 2001 7:13 AM Subject: Re: trabalhos interessantes VIII

> Pois leiam o trabalho de Greggory DeVore(Pasadena, California) no Prenatal
> Diagnosis de Janeiro de 2001: The Genetic Sonogram.Entre outras coisas ele
chega > a conclusão, isto nos Estados Unidos, que a triagem de anomalias
cromossomicas > por ultra-sonografia é mais eficiente do que o teste triplo.
> Quem quiser xerox é só pedir e mandar endereço com CEP.
>
> Prof. Thomaz Gollop
>
> Jaime wrote:
>
> > Aos colegas da lista
> >
> > Ultrasom para rastrear sindrome de Down é um método bastante pobre.
> >
> > Publicação em 28/02/2001 The Journal of the American Medical
Association > > (JAMA)
> >
> > A Dra. Rebecca Smith e o Dr. Bindman, da Universidade da Califórnia, em
São > > Francisco e seu grupo, realizaram uma meta análise de 56 estudos que
> > avaliaram a ultrasonografia de segundo trimestre como método rastreador
da > > sindrome de Down.
> > Os trabalhos escritos encontraram 130.365 fetos saudáveis que tinham
falso > > positivo para a sindrome cromossomial, contra 1.930 fetos realmente com
a > > sindrome de Down
> >
> > Todos os estudos selecionaram mulheres com risco de gerar fetos com
> > anomalias cromossomiais.
> >
> > Os marcadores ultrassonográficos usados, foram a prega nucal e o cisto
de > > plexo coroide, aquela mais confiável que este. Calcularam 79 falso
> > positivos para a prega nucal e 611 para o cisto de plexo coróide para
cada > > caso de Down detectado.
> >
> > O problema é que cada caso suspeito invariavelmente parte para
métodos > > invasivos e aí temos mais perdas de fetos saudáveis pelas complicações
dos > > métodos invasivos do que diagnósticos de Down.
> > Além disso a ansiedade imposta ao casal é imensurável, causando muito
> > sofrimento até o nascimento do bebê.
> >
> > Mais detalhes
> >
> > Second-Trimester Ultrasonography Impractical Screening Test for Down
> > Syndrome
> >
> > WESTPORT, CT (Reuters Health) Feb 27 - Second-trimester ultrasonography
is a > > poor method of detecting fetuses with Down syndrome, resulting in more
fetal > > losses than cases of the syndrome detected, according to a recently
> > conducted meta-analysis of published studies.
> >
> > Dr. Rebecca Smith-Bindman, of the University of California, in San
> > Francisco, and associates included in their analysis 56 studies that
> > recorded second-trimester prenatal ultrasonographic markers reportedly
> > associated with chromosomal abnormalities and outcome information. The
> > articles described findings for 130,365 unaffected fetuses and 1930
fetuses > > with Down syndrome.
> >
> > The sensitivity for Down syndrome was low, though the specificity for
each > > marker was >95%, the investigators report in The Journal of the American
> > Medical Association for February 28. The most accurate marker for
> > discriminating between unaffected and affected fetuses was a thickened
> > nuchal fold, but even this marker had a low sensitivity.
> >
> > The investigators calculated that between 4454 and 87,413 women at
average > > risk of having an affected fetus would need to be screened to detect one
> > case of Down syndrome. False positives would range from 79 for nuchal
fold > > to 611 for choroid plexus cysts for each case of Down syndrome detected.
> >
> > Dr. Smith-Bindman's team writes, "The use of the ultrasonographic
markers as > > an indicator for invasive testing with amniocentesis will lead to an
> > increase in the number of unaffected fetuses lost as a complication of
the > > procedure."
> >
> > On the other hand, the investigators note, if women considered to be at
risk > > on the basis of maternal age or serum testing results forego
amniocentesis > > due to the absence of ultrasonographic markers, the prenatal detection
of > > Down syndrome will actually be reduced.
> >
> > "Most physicians who I speak with don't really like using these
markers," > > Dr. Smith-Bindman told Reuters Health. "They don't believe they're
helpful > > in identifying babies truly affected by Down syndrome. But in this
> > medical-legal environment, they feel that once they've seen it they're
> > compelled to explain it to the woman and therefore recommend invasive
> > testing."
> >
> > This causes a huge amount of anxiety for women, Dr. Smith-Bindman noted.
> > "Unfortunately, even when a second ultrasound or amniocentesis shows the
> > baby is normal, women remain stressed about it until the end of
pregnancy," > > she said. "Women are concerned if they've been told, for example, that
their > > baby had a cyst in the brain."
> >
> > JAMA 2001;285:1044-1055.
> >
> > Jaime Nonato http://www.jaimenonato.com jaimen@zaz.com.br
> >
>

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