ABGC Boards Prenatal Study Questions
and Answers
22q11.2 deletion common cardiac features - ANSWER-75%
- Tet of Fallot
- Interrupted aortic arch
-VSD
- Truncus Arteriosus
Advantages of First Tri Screening over Quad - ANSWER-Increased sensitivity for T21
and T18
Includes T13
Risk assessment earlier
Eliminates incorrect dating issue
AJ ACMG recommended additional carrier screening and carrier screening - ANSWER-
Disease Carrier Frequency
Gaucher 1:15
SMA 1:40
Niemann Pick type A 1:90
Fancomi C 1:90
Bloom 1:100
Mucolipidosis type 4 1:120
Amniocentesis - ANSWER-- needle puncture of the amniotic sac to withdraw amniotic
fluid for analysis
- Typically performed between the 15th and 22nd week
- risk around 1/300-1/500 for pregnancy loss
Ashkenazi Jewish ACOG recommended panel - ANSWER-Disease Frequency
Canavan 1:40
CF 1:25
Familial dysautonomia 1:30
,Atrioventricular Canal Defect and associate chromosome risk - ANSWER-- Hole
between the chambers of the heart
- about a 50% risk of T21
Background rate for birth defects - ANSWER-about 3% of all babies are born with some
birth defect
-Account for about 20% of all infant deaths
cardiac findings in Down syndrome - ANSWER-- 50% of all cases have
- Can be any kind
- Most common is ASD
Cardiac findings in Edwards (T18) - ANSWER-- 90 %
- VSD, ASD, patent ductus arteriosus, pulmonary vlave anomaly
Cardiac findings in Patua (T13) - ANSWER-80%
- No pattern
- ASD, VSD, PDA, Pulmonary Valve anomaly, Dextrocardia (heart on right)
Categories of carrier assessment - ANSWER-- Targeted
- Population-based
- targeted population based screening
- expanded carrier screening
chorionic villus sampling (CVS) - ANSWER-- A technique associated with prenatal
diagnosis in which a small sample of the fetal portion of the placenta is removed for
analysis to detect certain genetic and congenital defects in the fetus.
- Generally completed between the 10th and 13th week
Choroid plexus cyst - ANSWER-- like a blister in choroid plexus of the brain
- often go away by end of pregnancy
- Slight increased risk for aneuploidy (particularly T18
Cleft Lip/Palate - ANSWER-- About 1/800-1/1000
-= Lip and palate form about 4-10 weeks post conception
- Clefting involving upper lip that can go left or right of midline. Can be bilateral or
unilateral
, - about 10% have a chromosome abnormality
CMV (herpes virus) - ANSWER-- If woman has primary infection can pass to child
Teratogen Risk
- Developmental disability
- hearing loss
- vision problems/loss
-Higher risk for SAB
- Other; jaundice, large liver and spleen, low birth weight, microcephaly, neuro problems
Common Ultrasound Markers - ANSWER--Short Femur/Humerus
- Echogenic Intracardiac Focus
- Increased NT fold
- Hypoplastic or absent nasal bone
- Echogenic Bowel
- Pyelectasis
- Choroid Plexus Cyst
- Ventriculomegaly
Confined placental mosaicism - ANSWER-a form of mosaicism that is observed in the
placenta but not in the fetus
Congenital Heart Defects - ANSWER-- Heart developing around 18 days
- about 1-2% overall incidence
- Association with chrom abnl is dependent on type of CHD
Cordocentesis (PUBS) - ANSWER-Sampling of the fetal blood via the umbilical cord
- not common but when preformed it is 18 weeks or later
- Loss risk less than 2%
- Can be used to clarify previous mosaic results
Critical periods of development: Week 3-16 - ANSWER-Nervous system
Critical periods of development: Week 3-7 - ANSWER-Heart
Critical periods of development: Week 4-8 - ANSWER-Ears/Eyes
Critical periods of development: Week 4-9 - ANSWER-Upper/lower limbs
and Answers
22q11.2 deletion common cardiac features - ANSWER-75%
- Tet of Fallot
- Interrupted aortic arch
-VSD
- Truncus Arteriosus
Advantages of First Tri Screening over Quad - ANSWER-Increased sensitivity for T21
and T18
Includes T13
Risk assessment earlier
Eliminates incorrect dating issue
AJ ACMG recommended additional carrier screening and carrier screening - ANSWER-
Disease Carrier Frequency
Gaucher 1:15
SMA 1:40
Niemann Pick type A 1:90
Fancomi C 1:90
Bloom 1:100
Mucolipidosis type 4 1:120
Amniocentesis - ANSWER-- needle puncture of the amniotic sac to withdraw amniotic
fluid for analysis
- Typically performed between the 15th and 22nd week
- risk around 1/300-1/500 for pregnancy loss
Ashkenazi Jewish ACOG recommended panel - ANSWER-Disease Frequency
Canavan 1:40
CF 1:25
Familial dysautonomia 1:30
,Atrioventricular Canal Defect and associate chromosome risk - ANSWER-- Hole
between the chambers of the heart
- about a 50% risk of T21
Background rate for birth defects - ANSWER-about 3% of all babies are born with some
birth defect
-Account for about 20% of all infant deaths
cardiac findings in Down syndrome - ANSWER-- 50% of all cases have
- Can be any kind
- Most common is ASD
Cardiac findings in Edwards (T18) - ANSWER-- 90 %
- VSD, ASD, patent ductus arteriosus, pulmonary vlave anomaly
Cardiac findings in Patua (T13) - ANSWER-80%
- No pattern
- ASD, VSD, PDA, Pulmonary Valve anomaly, Dextrocardia (heart on right)
Categories of carrier assessment - ANSWER-- Targeted
- Population-based
- targeted population based screening
- expanded carrier screening
chorionic villus sampling (CVS) - ANSWER-- A technique associated with prenatal
diagnosis in which a small sample of the fetal portion of the placenta is removed for
analysis to detect certain genetic and congenital defects in the fetus.
- Generally completed between the 10th and 13th week
Choroid plexus cyst - ANSWER-- like a blister in choroid plexus of the brain
- often go away by end of pregnancy
- Slight increased risk for aneuploidy (particularly T18
Cleft Lip/Palate - ANSWER-- About 1/800-1/1000
-= Lip and palate form about 4-10 weeks post conception
- Clefting involving upper lip that can go left or right of midline. Can be bilateral or
unilateral
, - about 10% have a chromosome abnormality
CMV (herpes virus) - ANSWER-- If woman has primary infection can pass to child
Teratogen Risk
- Developmental disability
- hearing loss
- vision problems/loss
-Higher risk for SAB
- Other; jaundice, large liver and spleen, low birth weight, microcephaly, neuro problems
Common Ultrasound Markers - ANSWER--Short Femur/Humerus
- Echogenic Intracardiac Focus
- Increased NT fold
- Hypoplastic or absent nasal bone
- Echogenic Bowel
- Pyelectasis
- Choroid Plexus Cyst
- Ventriculomegaly
Confined placental mosaicism - ANSWER-a form of mosaicism that is observed in the
placenta but not in the fetus
Congenital Heart Defects - ANSWER-- Heart developing around 18 days
- about 1-2% overall incidence
- Association with chrom abnl is dependent on type of CHD
Cordocentesis (PUBS) - ANSWER-Sampling of the fetal blood via the umbilical cord
- not common but when preformed it is 18 weeks or later
- Loss risk less than 2%
- Can be used to clarify previous mosaic results
Critical periods of development: Week 3-16 - ANSWER-Nervous system
Critical periods of development: Week 3-7 - ANSWER-Heart
Critical periods of development: Week 4-8 - ANSWER-Ears/Eyes
Critical periods of development: Week 4-9 - ANSWER-Upper/lower limbs
