Prenatal diagnosis is testing for diseases or conditions in a fetus before it is born. The aim is to detect birth defects such as Neural tube defects, Down syndrome, chromosomal abnormalities and genetic diseases. Common methods of prenatal diagnosis include invasive methods like amniocentesis, chorionic villus sampling, and cordocentesis as well as non-invasive methods like ultrasonography. Prenatal diagnosis provides information to help couples prepare for the birth of an affected baby and enables pregnancy termination as an option. Problems can include failure to obtain a sample or ambiguous chromosome results.
2. CON TEN TS
• I ntro ctio
du n
• Pu se o pre
rpo f natal diagno sis
• I ndicatio o pre
ns f natal diagno sis
• M e ds o pre
tho f natal diagno sis
• Pro m in pre
ble s natal diagno sis
3. Prenatal diagno is te
sis sting fo dise s o
r ase r
co
nditio in a fe s be re it is bo The
ns tu fo rn.
aim is to de ct birth de cts su as
te fe ch
N e ral tu de cts, D o n syndro e
u be fe w m,
chro o m abno alitie and ge tic dise s
mso al rm s ne ase
5. Pu se o pre
rpo f natal diagno
sis
•P rovid ing w id e s t p os s ib le rang e of c h oic e s to
w om e n at ris k of h aving c h ild w ith a g e ne tic
ab norm ality.
•P rovid e re as s u ranc e and re d u c e anx ie ty,
e s p e c ially am ong h ig h -ris k g rou p s .
•E nab le h ig h ris k w om e n to c ontinu e
p re g nanc y b y c onfirm ing th e ab s e nc e of a
c e rtain g e ne tic d is e as e .
6. • A llow th e c ou p le s to p re p are
p s yc h olog ic ally for th e b irth of
affe c te d b ab y.
• T o e nab le p re natal tre atm e nt of th e
affe c te d foe tu s .
• P rovid e ris k inform ation to c ou p le s
w h e n p re g nanc y te rm ination is an
op tion.
7. I ndicatio fo pre
ns r natal diagno
sis
• A dv d m rnal age >3 yrs o age
ance ate ( 5 f )
• Pre io s child w a chro o m abno ality
vu ith mso al rm
• F am histo fo a ge tic dise
ily ry r ne ase
• H isto o u x
ry f ne plaine fotu lo s o pe
d e s sse r rinatal deaths
• A bno alitie ide d in u u
rm s ntifie ltraso nd
• Othe high risk facto like m rnal illne s
r rs ate sse
9. M e ds o pre
tho f natal diagno
sis
I N VA S I VE N ON -I N VA S I VE
• A m nioc e nte s is • U ltras onog rap h y
• C h orionic villu s T w o d im e ns ional
s am p ling (C VS ) (2 D ) u ltras ou nd
• C ord oc e nte s is T h re e d im e ns ional
• F e tos c op y (3D ) u ltras ou nd
• D op p le r u ltras ou nd
10. I nv e M e ds Of
asiv tho
Prenatal D iagno
sis
11. A m ce sis
nio nte
• R e m oval of 1 0-2 0 m l of am niotic flu id from
th e ab d om inal w all u nd e r u ltras ou nd
g u id anc e arou nd 1 4 w e e k s of g e s tation and
its analys is for c h rom os om e b as e d
ab norm alitie s .
• E nab le s th e d oc tors to m e as u re th e alp h a-
fe to p rote in le ve l in th e am niotic flu id w h ic h
ind ic ate s w h e th e r th e foe tu s h as a b rain or
s p inal c ord d e fe c t.
13. Cho nic Villu S am
rio s pling
• R e m oval of s am p le of c h orionic villi u nd e r
u ltras onog rap h ic g u id anc e .
• C VS m ay b e u s e d ins te ad of am nioc e nte s is
u nle s s a s am p le of th e am niotic flu id is
ne e d e d .
• I n C VS , re s u lts are availab le m u c h e arlie r
in th e p re g nanc y.
15. Co ce sis
rdo nte
• P e rc u tane ou s u m b ilic al b lood s am p ling or
c ord oc e nte s is is u s e d w h e n rap id c h rom os om e
analys is is ne e d e d u nd e r u ltras onog rap h ic
g u id anc e .
• Vis u alis ation of th e u m b ilic al ve s s e ls b y
trans ab d om inal u ltras ou nd and e nab ling foe tal
b lood s am p ling .
• I t is u s u ally u s e d in th e m anag e m e nt of R h e s u s
is oim m u niz ation.
17. F e sco
to py
• Vis u alis ation of foe tu s b y m e ans of an e nd os c op e .
• I t c an b e u nd e rtak e n to d iag nos e a s u b tle
s tru c tu ral ab norm alitie s p ointing to a s e riou s
d iag nos is .
• C an als o b e u s e d to ob tain foe tal s am p le s for s om e
d iag nos is as inh e rite d s k in d is ord e rs and s om e
m e tab olic d is ord e rs .
19. N on-I nvas ive
M e th od s O f
P re natal
D iag nos is
20. U ltraso graphy
no
• I t offe rs valu ab le m e ans for p re natal d iag nos is .
• U s e d for d e te c ting m u ltip le g e s tation, d oc u m e nt
foe tal viab ility, c onfirm g e s tational ag e and loc aliz e
p lac e nta.
• I t is a non invas ive te c h niq u e w ith no ris k to th e
foe tu s or m oth e r.
• A s p e c ialis e d e x p e ns ive e q u ip m e nt and a s k ille d
e x p e rie nc e d op e rator are ne e d e d .
21. • I t is offe re d to th os e w ith a h is tory of g e ne tic
d is e as e .
• D e taile d foe tal anom aly s c anning is offe re d als o to
all p re g nant w om e n arou nd th e 1 8 w e e k s of
g e s tation as a s c re e ning p roc e d u re for s tru c tu ral
anom alie s .
• I t c an id e ntify fe atu re s w h ic h s u g g e s t u nd e rlying
c h rom os om al ab norm ality ind ic ating am nioc e nte s is .
23. 2 U ltraso graphy
-D no
• 2 -D U ltras onog rap h y is a
w id e ly u s e d te c h niq u e to
p rod u c e live 2 D im ag e s of th e
fe tu s .
• T h is typ e c re ate s tw o
d im e ns ional im ag e s th at h e lp
d oc tors to d e te rm ine th e b ab y's
g e s tational ag e and e valu ate it’s
g row th and d e ve lop m e nt.
• A s tand ard p re natal 2 -D
u ltras ou nd e x am u s u ally tak e s
ab ou t 2 0 m inu te s .
24. 3 U ltraso graphy
-D no
• I t w as 1 s t d e ve lop e d b y O laf von
R am m and S te p h e n S m ith at D u k e
U nive rs ity in 1 987
• 3-D U ltras onog rap h y is a w id e ly
u s e d te c h niq u e to p rod u c e live 3-D
im ag e s of th e fe tu s .
• I n 3D fe tal s c anning , ins te ad of th e
s ou nd w ave s b e ing s e nt s traig h t d ow n
and re fle c te d b ac k , th e y are s e nt at
d iffe re nt ang le s . T h e re tu rning
e c h oe s are p roc e s s e d b y a
s op h is tic ate d c om p u te r p rog ram
re s u lting in a re c ons tru c te d th re e
d im e ns ional volu m e im ag e of fe tu s 's
s u rfac e or inte rnal org ans .
25. D o r U ltraso nd
pple u
I t is a s p e c ial form of u ltras onog rap h y
th at im ag e s and e x am ine s b lood flow .
I t e x am ine s th e c h ang e in p itc h in th e
s ou nd w ave s p rod u c e d , w h ic h p rovid e s
inform ation ab ou t b lood flow . T h e
d ire c tion of b lood flow is s h ow n in
d iffe re nt c olors on th e s c re e n. T h is
typ e of im ag ing c an p rovid e d e tails
ab ou t c irc u lation w h ic h is p artic u larly
h e lp fu l if th e m oth e r h as h ig h b lood
p re s s u re or th e b ab y is g row ing m ore
s low ly th an e x p e c te d .
26. Pro m in pre
ble s natal diagno :
sis
• F ailu re to ob tain a s am p le or c u ltu re failu re .
• A n am b ig u ou s c h rom os om e re s u lt.
• A n u ne x p e c te d c h rom os om e re s u lt.
• R is k to th e m oth e r and th e foe tu s .
27. Prenatal Tre e
atmnt
• I n m os t s itu ations th e d iag nos is of p re natal
ab norm alitie s h as a s u b s e q u e nt op tion of
te rm ination of th e p re g nanc y.
• W h ile th is ap p lie s in m os t s itu ations , th e re is
c au tiou s op tim is m th at w ith th e ad ve nt of g e ne
th e rap y p re natal d iag nos is w ill, in tim e , le ad to
e ffe c tive tre atm e nt in ueo
tr.