Læknablaðið - 15.05.2001, Blaðsíða 33

FRÆÐIGREINAR / FÓSTURGREINING
þýðir. Neikvætt forspárgildi var í rannsókn
Nicolaides 99,9% sem þýðir að rannsóknin er mjög
góð til að útiloka að sjúkdómurinn sé fyrir hendi (1).
Fyrir þau 95% kvenna sem fá neikvætt svar (líkur á
litningagalla 1:300 eða minni) fylgir oftast léttir yfir
að búið sé að minnka líkur á tilteknum litninga-
göllum. Það er ekki síður mikilvægt að vekja athygli
verðandi foreldra á þeirri staðreynd að skoðunin
hefur verulega minnkað líkur á alvarlegum
fósturgöllum. Forspárgildin eru háð næmi og sértæki
(specificity) og algengi sjúkdómsins í þýðinu. Fyrir
eldri konur, þar sem litningagallar eru algengari, eru
jákvæðu og neikvæðu forspárgildin því betri en hjá
yngri konunum.
Omskoðun við 11-13 vikur getur leitt til grein-
ingar á alvarlegum vandamálum hjá fóstri. Við
núverandi aðstæður er öllum konum 35 ára og eldri
boðið upp á litningarannsókn fósturs, en yngri
konum stendur engin fósturgreining til boða með
tilliti til litningagalla fósturs. Þegar hægt er að beita
öðrum aðferðum en þeim sem einblína á aldur
móður til að greina afbrigðilegar þunganir, er eðlilegt
að endurskoða þessar reglur. Allir verðandi foreldrar
sem þess óska ættu að eiga kost á snemmómskoðun
og líkindamati með tilliti til litningagalla hjá fóstri.
Heimildir
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heart and great arteries in first trimester chromosomally
abnormal fetuses. Am J Med Genet 1997; 69: 207-16.
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translucency in trisomy 21 fetuses: relation to narrowing of the
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