3. antenatal screening Flashcards
what are 3 downsides to screening
- false positives
- harm from screening or further tests
- cost
what is FPR
false-positive ratio
The ratio of patients who are disease-free but test positive for an illness, as a result of error, to all patients who do not have the disease
what theory is used to estimate the probability of a diagnosis, given the appearance of specific signs, symptoms, or test outcomes.
bayes theorem
sickle cell and thalassaemia:
who gets screened, when and how is it done?
- pregnant women (also based on ethnic origin)
- pre-conception to 10 weeks
- blood test
if a pregnant woman tests positive for sick cell/thalassaemia:
what prenatal diagnosis is used?
CVS (Chorionic villus sampling)
amniocentesis
if a pregnant woman tests positive for sick cell/thalassaemia:
what would happen if the fetus is affected
termination
early specialist care
infectious disease:
-who gets screened and when does it happen
all women
at booking
infectious disease screening:
what gets screened for and how
HIV, Hep B syphilis
serology (diagnostic examination of blood serum)
what are the next steps if tested positive for HIV?
- maternal treatment
- high risk antenatal care
- prevent transmission to neonate
what are the next steps if tested positive for Hep B
- change antenatal care prevent transmission
- neonate receives vaccine
what are the next steps if tested positive for syphilis
maternal treatment to prevent congenital syphilis
chromosomal abnormalities:
- who gets screened
- when does it happen
all preg woman
between 11+0-13+6
chromosomal abnormalities:
how is screening performed
combined test:
- fetal nuchal translucency (fluid @ back of neck)
- maternal serum - beta-hCG and PAPP_A
how is the risk of trisomy 21 increased
with maternal age
what BRAIN abnormalities can be detected by US
acrania
holoprosencephaly
what SPINE abnormalities can be detected by US
open spina bifida
what FACE abnormalities can be detected by US
facial cleft
anopthalmia
what NECK abnormalities can be detected by US
cystic hygroma
what THORAX abnormalities can be detected by US
congenital diaphragmatic hernia
what ABDOMINAL WALL abnormalities can be detected by US
exomphalos (omphalocele)
gastroschisis
what URINARY TRACT abnormalities can be detected by US
biliary renal agenesis
urethral obstruction
what EXTREMITIES abnormalities can be detected by US
club foot
arthrogryposis
what SKELETAL abnormalities can be detected by US
skeletal dysplasia
achondroplasia
what Congenital heart disease can be seen (US) via four chamber view
- AV septal defect
- hypoplastic left heart syndrome
- ventricular septal defect
- Ebsten’s anomaly
what Congenital heart disease can be seen (US) via great vessels view
- transposition of the great arteries
- tetralogy of Fallot
- common arterial trunk
- coarctation of the aorta
- aortic valve stenosis
