ultrasound anomalies Flashcards
non-immune hydrops
-any causes of fetal hydrous not caused by RBC alloimmunization
-1/1500-1/3800 births
+up to 35% discovered incidentally on ultrasound
hydrops
refers to abnormal fluid buildup in 2 or more locations
ascites
fluid buildup in the abdomen
cardiovascular hydrops
- most common mechanism (17-35%)
- due to increased central venous pressure
chromosomal abnormality associated hydrops
- 7-16% of cases
- can be due to cardiac anomalies, lymphatic dysplasia abnormal myelopoeisis, etc
infection associated hydrops
- 5-7%
- can be due to anemia, anoxia, endothelial cell damage, and increased capillary permeability
- CMV, too, parvo, syphilis, herpes, rubella, coxsackie virus, leptospirosis, trypanosome cruzi
twin-twin transfusion associated hydrops
- 3-10%
- due to hyper___emia and increased central venous pressure
aneuploidy and hydrops
- monosomy X (42-67% cases)
- Trisomy 21 (23-30%)
- Trisomy 13, 18, 12
syndromic hydrops
- Noonan
- Pena-Shokeir syndrome
- myotonic dystrophy
- multiple pterygium syndrome
- skeletal dysplasias
pena-shokeir syndrome
- caused by mutations of the DOK7 and RAPSN genes
- can cause IUGR, joint contractures, pulmonary hypoplasia, and facial anomalies
- also called fetal akinesia deformation sequence
metabolic conditions and hydrops
- galactosialidosis
- GM1 gangliosidosis
- sialidosis
- MPS IVA
- Farber disease
- most of these not evaluated prenatally, as they aren’t what we worry about most with hydrops
parvo pathogenesis
affects bone marrow by preferentially infecting and replicating inside erythroid cells
-see hand and neck depression
-incredibly anemic baby with hydrops starting 2-4w post-maternal infection
+usually starts with ascites
*10% risk of fetal hydrous after maternal infection (which is usually mild)
parvo treatment
transfusion at 19-22w usually helps the fetal bone marrow recover and baby will be okay
MCA doppler
looks at blood vessel in fetal brain to show how fast blood is being shunted and therefore how anemic the fetus is
+higher doppler values indicate more significant anemia
PUBS
-used to be used to study hematocrit levels and find out if baby is anemic
-now used to transfuse following MCA
+use dense pellet of high crit irradiated O negative blood to transfuse
estimated fetal weight
- BPD
- HC
- abdominal circumference
- femur length
PUBS risk
- failure of procedure and continued anemia in fetus
- ROM, preterm labor or delivery
- typically done after 18w & before 34w to avoid problems
ultrasound
screening method completed at different times in pregnancy to identify possible issues or differences, monitor growth and fluid levels as well as guide additional procedures and further care
level II anatomy scan
- typically done between 18-22w to allow for further follow-up and timing of results
- in depth look at head, face, neck, chest, abdomen, spine, extremities and genitalia
early anatomy
completed transvaginally around 14w for cases suspicious of abnormality or family history
-followed up by later scans
intracardiac echogenic focus (EIF, IEF)
- soft marker with possible increased risk for Down syndrome
- identified commonly in left ventricle
- sometimes not reported anymore because it does not impact function
- ethnic variation-more common in Asian population
pylectasis
-dilation of the renal pelvis
-more common in males
-can be indicative of a GU structural anomaly
+if greater than 4mm at anatomy followup at 28w-new cutoff 7mm
-slightly increased risk for Down syndrome, but less concerning if isolated
absent/hypoplastic nasal bone
-echogenic line within the bridge of fetal nose
-significant risk of Down syndrome
+51x more likely, BUT can be familial and ethnic (if Caucasian could be 132x more likely, if Afro-Carribean only about 8.5x more likely)
+typically not associated with other conditions
hypoplastic nasal bone cutoff
less than 5th percentile indicates abnormal
echogenic bowel
- increases risk for aneuploidy (LR=6), and CF
- can be seen in cases of fetal infection (namely CMV)
- can also be associated with bowel malformations or rupture as well as intra-amniotic bleeding
CF risk with echogenic bowel
2% if parental carrier status unknown
CPC incidence
-seen in 1% of all pregnancies and 50% of trisomy 18 pregnancies
+Tri18 LR=7
*however it is rare for Tri18 to only be seen with this finding
CPC
-relatively common abnormality seen within fetal brain ventricles in area that makes CSF
-in the absence of a karyotypic abnormality there is no association with fetal abnormality or developmental problems
+often times NIPS is first line testing now
-rarely can look similar to intracranial hemorrhage
increased nuchal fold
- abnormal measurement at posterior fossa at 18-24w
- increases risk for DS (LR=17-especially if found before 20w), cardiac anomalies, single gene disorders such as skeletal dysplasias, Noonan, multiple pterygium syndrome
- fetal echo recommended as follow-up
club foot
- 1 in 1000 live births, typically isolated with good prognosis
- can be related to positional factors (oligo, multiple gestation, uterine anomalies such as fibroids)
- can be a sign of neurological, muscle or connective tissue disorders including >50 genetic conditions
omphalocele
- herniation of abdominal contents into umbilical cord
- 50% risk of chromosome abnormality
- increased need for c-section delivery
gastroschisis
-intestines protrude into amniotic fluid without covering-typically to the right of cord
-usually sporadic and not due to karyotypic abnormality
+typically due to a vascular event that occurred
-seen more commonly in young mothers, particularly smokers
-usually prognosis is fine, some risk for IUFD, but fine if survive to birth-can sometimes need surgical resection
skeletal dysplasias
-more than 300 types caused by single gene abnormalities
+makes pin-pointing type difficult prenatally, though some have characteristic features
+if detected in 1st or 2nd tri likely lethal, non-lethal present later or postnatally
-X-rays and autopsy can help determine recurrence risks
identifying skeletal dysplasia on ultrasound
-measuring long bones (humerus & femur)
+on anatomy making sure these & digits are present
+if these are short or oddly shaped measure all 12
-looking at shape of the head
-measuring chest circumference/size
preaxial extra digits
more concerning from genetics POV than post-axial which is more likely to be isolated or familial
-polydactly more common in AA populations and can be inherited in AD fashion
clefting
- 1/1000 live births
- typically isolated, but can be part of 300+ syndromes
