Ch. 53, 55-64 All Flashcards
AFP Alpha-Fetoprotein
Fetal protein made by YS then fetal liver; sample in wks 15-18; Elevated- neural tube defects, abd wall defects, etc; Low- Trisomies; US-amniocentesis when MSAFP elev and US offers no explanation
CVS Chorionic Villus Sampling
US guided biopsy of placenta or chorionic villi; detects chromosomal anomalies, biochemical or metabolic disorders, thalassemia, and sickle cell; Performed early (GA 10-12wks); US- full survey first and determine locations
Amniocentesis
US guided sampling of amniotic fluid for genetic testing; GA- 15-20 wks (earlier has risks); US- full survey first; collect away from fetus, central placenta, umbilical cord, and near maternal midline to avoid UT vessels
Aneuploidy
Abnormal number of chromosomes; High prevalence in patients referred for amniocentesis b/c of advanced maternal age, abnormal AFP, abnormal quad screen, or US detection of multiple fetal anomalies.
Placentamegaly
Enlarged placenta >600 g; Assoc w/maternal and fetal disorders, maternal diabetes, and Rh incompat; US- placenta thickened >4cm from subplac veins to amniotic fluid junction
Cordocentesis
Obtains fetal blood through US guided needle aspiration of umbilical cord to test chromosomes; FISH has decr need; US- more for guided transfusions in Rh isoimmunization
Nuchal Transluceny NT, “Translucency Three, Fold Five”
Abnormal fluid collection at neck; Strongly assoc w/aneuploidy; US- measure btwn 10-14 weeks; clear margins in sag plane away from amnion; >3mm abnormal
Polyhydramnios
amniotic fluid volume >2000 ml (AFI >20cm); caused by maternal diabetes (most common), fetal Macrosomia, and Rh isoimmunization; USA- Freely floating fetus w/in the swollen amniotic cavity, accentuated fetal anatomy, AFI = or >20cm (mild).
Oligohydramnios
Overall reduction in AFI; fetal crowding and decreased fetal movement; USA- AFI less than 5cm; poor scanning resolution
Chorioid Plexus Cysts
Common; CSF trapped w/in the neuroepithelial folds; usually isolated; often resolve by 22-26 weeks GA; may be associated w/aneuploidy; USA- Round/ovoid anechoic w/in the CP; sizes from 0.3 – 2 cm; uni- or bilateral; solitary or multiple; unilocular or multlocular
Ventriculomegaly
Dilatation of the ventricles w/in the brain; occurs w/obstruction of CSF flow; USA- lateral ventricular >10 mm; “dangling choroid sign;” possible dilatated 3rd and 4th ventricles
Thickened Nuchal Fold, “Translucency Three, Fold Five”
Measured in 2nd trimester in plane w/CSP, Cere, and CM; risk for aneuploidy; normal is less than 5mm up to 20 wks
Diabetes Mellitus/ Macrosomia
Diabetes increases risks of complications, including macrosomia; USA- correct dating important for size, polydydramnios, caudal regression syndrome
Cardiac Anomalies
Associated w/various anomalies, including trisomy 21 (Down’s) and polyhydramnios
oMphalocele M=membrane
Persistent bowel and/or liver within umbilical cord beyond 12th week; worse than gastroschisis, especially if contains liver; abdominal echogenic wall mass w/surrounding membraine; ascites
GastRoschisis R=Right
Abdominal wall defect (almost always to right of umb cord) w/herniated bowel passing through; elev. MSAFP; USA- free floating bowel seen outside abdominal cavity w/o a covering membrane
Spina Bifida
Cleft or opening in spine; USA- flattened frontal bones, obliterated CM, “banana” cerebellum; SB Occulta-opening covered w/skin or hair, normal MSAFP, difficult to detect w/US; Meningocele- open defect w/only protrusion of meninges, USA- splaying posterior ossification centers w/V or U shape, cleft in skin, saclike anechoic protrusion; Meningomyelocele- common defect w/meninges and neural elements protruding, USA-splaying w/V or U shape, cleft in skin, saclike protrusion that contain neural elements
Talipes (clubfoot) “Tap the ball with your club”
Deformities of foot/ankle. USA- may appear as persistent abnormal inversion of the foot perpendicular to the lower leg.
Rocker Bottom Feet
Prominent heel and a convex sole; associated w/multiple syndromes, especially trisomy 18. USA- can look similar to clubfoot.
Amniotic Band Syndrome “Bands are bad”
“Amniotic bands” (fibrous tissue stands) compress fetus; causes fetal malformations involving the limbs, craniofacial region, and trunk; USA- malformation of the fetus, echogenic bands present w/in the amniotic cavity- follow closely to see where band is attached
Synechiae
UT scars from previous instrumentations used in the UT (usually curettage), c-sect, or episodes of endometritis; leads to amniotic sheets. USA- echogenic nonfloating bands that cross throught the amniotic cavity
Amniotic Sheets
echogenic nonfloating bands cross through the amniotic cavity; thicker than amniotic band syndrome; don’t cause fetal malformations; USA- fine echodense line in the UT cavity; surround fetus or be freely mobile; maternal blood flow w/in
Polydactyly
Extra digits. USA- extra fingers or toes.
Syndactyly “Syn/Stuck”
Fused digits. USA- difficult to distinguish on US.
Clinodactyly
Overlapping digits. USA- difficult to distinguish on US.
Amelia
Congenital absence of one or more extremities. USA- may be recognized prenatally.
Trisomy 13, 18, 21 PEDs
13- Patau; 18-Edwards; 21-Down’s
Trisomy 13
Patau’s syndrome; extremely severe; extra chromosome 13; consists of multiple anomalies; lethal w/80% of infants dying w/in the 1st month. USA- Holoprosencephaly, corpus callosum agenesis, microcephaly, facial anomalies (ex. Cyclopia and single nostril), cleft lip/palate, heart defects, omphalocele, renal anomalies, limb anomalies, cystic hygroma, echogenic chordae tendineae, IUGR, 2 vessel cord, polyhydramnios.
Trisomy 18
Edwards’ syndrome; 2nd most common w/extra chromosome 18; lethal anomaly w/90% of infants dying w/in the 1st year; USA- cardiac anomalies, cranial anomalies, low-set ears, micrognathia, cleft lip, persistently clenched hands, radial aplasia, Omphalocele, diaphragmatic hernia, neural tube defects, cystic hygroma, renal anomalies, polyhydramnios, IUGR, 2 vessel cord, nonimmune Hydrops.
Trisomy 21
Down syndrome; one of most common chromosomal disorders; extra #21 chromosome; association w/advanced maternal age and abnormal nuchal translucency. USA- limited; nuchal fold 6mm or greater, extremity anomalies, shortened femur or humerus, duodenal atresia, heart defects, IUGR, mild pyelectasis, echogenic bowel, mild Ventriculomegaly, echogenic intracardiac focus, absence of nasal bone at 11-14 weeks.
Turner Syndrome
45X; absence of the X or Y chromosome; not associated w/advanced maternal age; /elevated MSAFP when cystic hygroma is present. USA- cystic hygroma, cardiac anomalies, general lymphedema, Hydrops, renal anomalies, short femurs, oligohydramnios, especially when severe renal anomalies exist.
Coarctation of the Aorta
Discrete shelflike lesion in the isthmus of arch or at site of ductal insertion near left subclavian; this and ventricular septal defects most common cardiac defect w/Turner’s Syndrome
Acrania
Lethal; absence of cranium w/complete, although abnormal, development of the cerebral hemispheres. USA- brain tissue w/o a calvarium; disorganization of the brain tissue; prominent sulcal markings; “Mickey Mouse” bilobed brain in 1st trimester.
Anencephaly
Most common neural tube defect; “absence of the brain;” lethal; USA- detectable at 10-14 weeks’ GA; Acrania; reduction in CRL w/advancing GA; 2nd trimester appears as absent cerebral hemispheres along w/absence of the skull; rudimentary brain tissue (cerebrovasculosa); bulging fetal orbits (fetus looks “froglike”)
Ectopia Cordis
Exposed heart outside chest wall through a cleft sternum. USA- heart outside the thoracic cavity; a portion or all of the heart may protrude through the defect in the sternum; pericardial and pleural effusions common.
Duodenal Atresia
Blocked duodenal lumen; prohibits passage of swallowed amniotic fluid; Atresia or narrowing below obstruction; amniotic fluid backs up into the duodenum and stomach. USA- Two echo-free structures (stomach and duodenum) in upper fetal abdomen “double bubble sign;” hydramnios almost always seen; IUGR
Esophageal Atresia
Blocked esophagus; a fistula that communicates between the trachea and esophagus may allow passage of amniotic fluid into the stomach. USA- polyhydramnios and absent stomach over repeated studies; fluid may be in the stomach because of fistula; blind-ending esophagus during fetal swallowing; “upper neck sign.”
Diaphragmatic Hernia
Herniation of the abdominal viscera into chest that results from a defect in the fetal diaphragm; most common occurs posteriorly and laterally. USA- left-sided congenital diaphragmatic hernia- cardiac silhouette displaced to the right w/ectopic stomach in the chest; sag may show defect in diaphragm; fetal lung may be small and compressed; cardiomediastinal shift critical in diagnosis; intrathroacic liver; Through foramen of Bochdalek
Fetal Hydrops
Free fluid or edema w/in a fetus in at least 2 areas; USA- fetal ascites; pleural effusion; skin edema >5-6mm; pericardial effusion >2mm; placental edema >4-4.5cm in true A/P diameter
Rh isoimmunization
Causes (IHF) Hydrops Fetalis because of maternal Rh antigens attacking fetus. USA- evidence of ascites, pleural effusion, and/or skin edema, thickened placenta and hydramnios
Cystic Hygroma
Malformation of lymphatic system leads to single or multiloculated lymph-filled cavities around neck; may lead to fetal Hydrops, even death. USA- bilateral large cystic masses at the posterolateral borders of the neck; in severe cases, may surround neck and head and upper trunk; may have dense septations
Meconium Peritonitis
Fetus has a sterile chemical peritonitis secondary to in utero bowel perforation; may have meconium Pseudocyst. USA- calcifications seen on peritoneal surfaces or in the scrotum via the processus vaginalis; ascitic fluid may be echogenic; hydramnios
Epignathus
Teratoma in the oropharynx; Highly complex and contain solid, cystic, or calcified components; swallowing impaired, resulting in hydramnios; small stomach. USA-abnormal positioning of tongue; small stomach; hydramnios
Fetal Goiter
Enlarged fetal thyroid; may be from maternal thyroid disease. USA- symmetrical, solid, homogeneous mass arising from the anterior fetal neck; hydramnios and a small or absent stomach
Cleft Lip
Common; failure to fuse primary and secondary palate; cleft courses anteriorly through the upper lip and alveolus; unilateral or bilateral; occurs in isolation or w/other anatomic and karyotypic abnormalities. USA-modified coronal plane as gap in upper lip; may affect nose (swelling, flattened, widened, or intact)
Cleft Palate
Lateral palatine processes fail to fuse at midline; w/ or w/o cleft lip. USA- a challenge because of bony shadowing; use coronal and axial planes, 3D (use caution if patients can see abnormality before doctor has had a chance to counsel them)
Dandy-Walker Malformation
Agenesis or hypoplasia of cerebellar vermis; dilatation on the fourth ventricle and enlargement of the posterior fossa. USA- posterior fossa cyst, splaying of cerebellar hemispheres, enlarged CM, ventriculomegaly; cardiac anomalies, polydactyly, facial clefts, and urinary tract anomalies
Arnold Chiari Malformation
Banana-shaped cerebellum, displaced downward into the foramen magnum and lemon-shaped head resulting from the downward pull that occurs w/open spina bifida.
