Ultrasound Findings Flashcards
What is an absent nasal bone
no bony part of the nasal bridge can be identified
What is an absent nasal bone most commonly associated with
T21
What is the likelihood ratio for absent nasal bone in African American, Asian, Chinese/Japanese, and Caucasian populations
AA=8.8
Asians= 14.2
Chinese/Japanese= 15.3
Caucasians= 31.3
What is a likelihood ratio
Used to assess the value of a diagnostic test by comparing the likelihood that a patient with a disease has a particular test result compared to someone without the disease.
The higher the LR, the more likely it is that the ultrasound finding is consistent with a genetic etiology
What are anterior clefts
Can extend through the lip and into the primary/hard palate
What are posterior clefts
CANNOT be visualized on u/s bc they include clefts of the secondary/soft palate
When is the susceptible period for clefting
4th-12th embryonic weeks (6-14 weeks GA)
Unilateral clefts account for ___% of CL+/- CP while bilateral clefts account for the remaining ___%
90; 10
Clefts extend into the palate in ___% of cases that are unilateral and in ___% of bilateral cases
70; 85
What is the order of the most common clefting patterns
(L unilateral, Bilateral, R unilateral)
- L unilateral
- R unilateral
- Bilateral
Ratio is 6:3:1
What is the incidence of CL +/- CP? Which gender is more likely to have CL +/- CP?
1 in 700; Males
Male to Female ratio is 2:1
What populations have the highest frequency of CL+/- CP
Native American and Asian populations
What are potential candidate genes for CL +/- CP
IRF6, MSX1, SATB2, FGFR1
What are the teratogenic associations that can result in CL +/- CP
Alchohol, hyperthermia (fever), methotrexate, maternal PKU, hydantoin, trimethadone, aminopterin, retinoic acid, valproic acid, smoking (odds ratio 1/3)
What is the detection of CL +/- CP on u/s
65-70% depending on the abnormality present
What are the testing recommendations for CL +/- CP identified on u/s
chroms, microarray (specifically for 22q11.2), comprehensive fetal u/s and echo should be offered to detect other defects and monitor for polyhydramnios second to swallowing issues
Parental exams for lip pits, craniofacial abnormalities, single central incisor, hypotelorism, and olfactory issues to r/o conditions like Van der Woude and AD holoprosencephaly
What is the recommended treatment for CL +/- CP
sx correction for CL usually occurs shortly after birth and CP between 6-18mo
Complications prior to sx may include poor feeding that could result in poor weight gain, poor dentition, and hearing problems
What is the general population risk for isolated CL +/- CP
0.1%
What is the empiric risk for a first degree relative with CL +/- CP
4-8%
Bilateral CL+CP=8.0%
Bilateral CL only= 6.7%
Unilateral CL+CP= 4.9%
Unilateral CL alone= 4%
What is talipes equinovarus
Clubfoot; foot brought downward and inward which cannot be brought to a neutral position
Half are bilateral; if it is unilateral, R side is usually affected
What is talipes calcaneovalgus
Foot is bent backward at the ankle and turned out with the foot bones in normal position relative to each other
Unlikely to be syndromic or the result of neurological impairment/syndromes
What is metatarsus varsus
forefront of the foot is turned inward and bent backward while heel and ankle remain in normal position. Usually mild and does not require sx
Unlikely to be syndromic or the result of neurological impairment/syndromes
What is the incidence of clubfoot? Which gender is more likely to have clubfoot?
1 in 1000; more common in males (2:1)
What populations have the highest frequency of clubfoot
High incidence in Polynesian population (6.5-7 in 1000)
What is the general population risk for clubfoot
0.1%
What is the empiric recurrence risk in a first degree relative with clubfoot
2-7%
~2% risk to sibs of a male with clubfoot; ~5% risk to sibs of a female with clubfoot
metatarsus varsus and talipes calcaneovalgus appear to run separately from equinovarus and may have an increased rr of 4-5% to sibs
False positives up to ___% in the 3rd tri using u/s for clubfoot. __% of cases do not develop/present until the 3rd trimester
40; 10
What are some causative factors in the intrauterine environment that can cause clubfoot
Twins. oligohydramnios, amnion rupture sequence, fetal positioning, placental insufficiency, maternal infection, maternal toxin exposure
What are testing recommendations for suspected clubfoot
amnio with karyotype and CMA
can consider genetic testing if specific condition is suspected (ex: distal arthrogryposis type 1- bilateral equinovarus)
comprehensive u/s to r/o additional anomalies
fetal MRI and echo may be indicated in complex cases
What is the recommended treatment for clubfoot
sx occurs in 20-80% of cases; most commonly, Ponseti technique is used (4-6wks long leg plaster casts, more casting, abduction brace worn during sleep until ~4yo)
Where should patients with clubfoot be referred
Orthopedic surgeon, postnatal genetics eval with pediatric geneticist
What fraction of clubfoot cases are isolated and syndromic
2/3 are isolated
1/3 are complex (other systems involved; 10-30% are associated with T13/T18)
What is a choroid plexus cyst
trapped cerebrospinal fluid within a fold of the primitive neuro tissue with subsequent accumulation of cellular debris
When can a choroid plexus cyst be visualized on u/s
as early as 9wks GA, but often seen between 16-25wks GA
What is the incidence of choroid plexus cyst
0.5-4% of routine mid-gestation u/s exams
What does the presence of a choroid plexus cyst indicate and what percentage of these case have a choroid plexus cyst
T18; 40-50%
What are the recommendations from ACOG concerning the identification of a choroid plexus cyst
amnio if serum screening is abnormal or the person is 32yo or older at delivery. CMA may also be considered but data is limited on the detection of microdel/dup syndromes in presence of CPCs
How many choroid plexus cysts disappear
> 95% disappear before 26wks (even those with an abnormal karyotype)
What should the follow up be following identification of choroid plexus cysts
Consider fetal echo; f/u u/s for growth can be considered since T18 is associated with IUGR
What is nuchal translucency and when is it measured
accumulation of fluid in the fetal neck ; measured between 11-14 weeks
What are the 95th and 99th percentile cutoffs for NT
3.0mm and 3.5mm respectively
What are some explanations for an increased NT
- cardiac failure secondary to abnormalities of heart/great arteries
- venous congestion of head + neck
- failure of lymphatic drainage bc of impaired fetal movement
- delayed/abnormal development of lymphatic system
- altered composition of ECM
- Chromosome abnormalities
- Microdel/dup syndromes
- Single gene disorders
What are the structural defects associated with increased NTs
CHDs, orofacial clefts, diaphragmatic hernia, omphalocele, body stalk anomalies
What are the testing recommendations following increased NT
fetal karyotyping by CVS/amnio; CMA and testing for Noonan should be discussed; A detailed level II u/s w fetal echo is recommended
What are adverse pregnancy outcomes associated with increased NT
Progression to fetal hydrops, fetal death, major cardiac/structural anomalies
What is hydronephrosis/pyelectasis
dilation of the fetal pelvis
What is the cutoff for a dilated renal pelvis in patients with hydronephrosis/pyelectasis
greater than or equal to 4mm at <33wks; greater than 7mm at >33wks
What is the incidence of hydronephrosis/pyelectasis and which gender is more likely to have the finding
found in ~2-3% of fetuses; more commonly seen in males (2:1 ratio)
What are alternative explanations (non-genetic) for hydronephrosis/pyelectasis finding on u/s
Ureteropelvic junction obstruction (makes up ~44-65% of cases, most of which are unilateral)
Posterior urethral valves (PUVs)- the most common cause of bladder obstruction, may present prenatally with oligohydramnios, bilateral hydronephrosis, and subcortical renal cyst formation
What genetic condition is associated with hydronephrosis/pyelectasis and what is the likelihood ratio
T21; ~2.78
What are the testing recommendations following a finding of hydronephrosis/pyelectasis on u/s
NIPT, confirmatory amnio w karyotype, consider CMA; serial targeted sonography (q4-6wks)
Majority of fetuses have spontaneous resolution/regression across ALL degrees of hydronephrosis on F/U
Pediatric nephrology consult can be delayed until ~2-3d of life
What is a hyperechoic bowel/echogenic bowel/hyperechogenic bowel
Bright sight seen within the bowel on u/s
Dx is subjective and more pronounced echogenicity is associated with a higher likelihood for an associated risk
What is the prognosis for an isolated finding of echogenic bowel
Most cases that are isolated in normal fetuses resolve over time and result from normal outcomes
What are the associated anomalies/conditions associated with hyperechoic bowel/echogenic bowel/hyperechogenic bowel
GI malformations (bowel atresia, bowel volvulus (loop of intestine twists around itself and the mesentery that supplies it, causing a bowel obstruction), etc.)
CF (meconium ileus, caused by obstruction of the small bowel w abnormally thick meconium in 10-15% of infants with CF)
Viral infections (congenital infections such as CMV, toxoplasmosis, and parvo B19)
DS or other chromosome abnormality
IUGR or IUFD
Intra-amniotic bleeding (fetal swallowing of blood, have a good prognosis if no additional anomalies)
What are the testing recommendations after identification of hyperechoic bowel/echogenic bowel/hyperechogenic bowel
Amnio offered in all cases. Chroms, consider viral PCR studies, consider CMA, prenatal analysis for CF
Noninvasive options should include NIPT, maternal serology (CMV, toxo), parental CF screening)
What is the follow up after diagnosis of hyperechoic bowel/echogenic bowel/hyperechogenic bowel
Additional u/s to r/o other anomalies
Referral to pediatric sx (unless resolved) and clinical geneticist
What is an intracardiac echogenic focus and what is suspected to cause it
area of increased echogenicity similar to or greater than that of surrounding bone within the fetal heart; thought to be caused by microcalcification within the papillary muscle
What is the incidence of intracardiac echogenic focus? Where is the finding typically found?
0.5-20%; most often in the L ventricle, rarely the aorta
What is the likelihood ratio associated with intracardiac echogenic focus
5.08-5.83
What are the testing recommendations following identification of intracardiac echogenic focus
In low risk patients, no f/u or testing indicated
In high risk patients (increased age), prenatal dx for chrom conditions, consider CMA
What is mild ventriculomegaly
width of the atria of the lateral ventricles exceeding 10mm (range between 10-12mm)
What is moderate ventriculomegaly
width of the atria of the lateral ventricles between 13-15mm
What is severe ventriculomegaly
width of the atria of the lateral ventricles equal to or exceeding 15mm
Also known as hydrocephalus. Severe ventriculomegaly is the dx prenatally, hydrocephalus is the post birth dx
What are the associated anomalies/conditions with mild ventriculomegaly
Underlying structural anomalies (seen in 40% of cases; can include NTDs, Dandy Walker Malformation, Agenesis of the corpus callosum, etc.)
Chromosome abnormalities (typically DS)
Other genetic conditions (Aicardi syndrome, CHARGE, Walker-Warburg, VACTERL, Apert, Hurler)
Congenital infections (toxoplasmosis, CMA, rarely parvo or rubella); can cause decreased reabsorption of CSF or cerebral atrophy; accounts for 1-5% of mild cases, 10-20% of severe cases
Intracranial hemorrhage (due to congenital/acquired bleeding disorders), increased risk for IUGR
What is the most common associated anomaly with ventriculomegaly
NTDs
What is the likelihood ratio for mild ventriculomegaly with other sonographic findings? Isolated?
27.52; 3.81
What are the testing recommendations for mild ventriculomegaly
Level II u/s to confirm ventriculomegaly and r/o associated anomalies (up to a 12% False + rate)
Amnio for chroms with or without CMA, AFP and acetylcholinesterase
PCR for toxoplasmosis, CMV, rubella, and parvo (with addition of viral studies, specificity and PPV are 100%)
Noninvasive= NIPT, maternal titers for IgG + IgM (lower specificity)
What is the prognosis for isolated mild ventriculomegaly? Persistent mild ventriculomegaly?
Mild form rarely causes significant cortical thinning (primarily cause of DD/ID in children with hydrocephalus)
Children with persistent (NOT those whose ventriculomegaly regresses) mild, isolated ventriculomegaly are at increased risk for neurodevelopmental delay, including cognitive, language, and behavioral deficits
No indication that these individuals are at increased risk for seizures or health complications
What is the follow up for mild ventriculomegaly identified on u/s
serial u/s to assess changes, identify late onset brain abnormalities, and assess for macrocephaly
possible fetal MRI in late 2nd and 3rd tri
possibly speak with pediatric neurology, pediatric geneticist
What is a cystic hygroma
congenital malformations of the lymphatic system (most commonly in the posterior neck
What is the difference between an increased nuchal translucency and a cystic hygroma
septations and the appearance of multiple fluid spaces
What is the incidence of cystic hygromas
0.2-1%
What are the associated anomalies/conditions with cystic hygroma
2/3 identified in the 2nd tri have an abnormal karyotype, with the majority being Turner syndrome
CHDs, Noonan, multiple pterygium syndrome, lethal skeletal dysplasias, Fryns syndrome, teratogenic exposure from alcohol
What are the testing recommendations when cystic hygroma is identified on u/s
amnio with chroms, CMA and disease specific genetic testing should be considered
Detailed level II u/s with fetal echo to look for associated anomalies. Periodic u/s to monitor progression into hydrops
What is the likelihood ratio for cystic hygroma
11-23.3
What is the prognosis for a fetus with cystic hygroma
chance of a healthy outcome is between 6-10%. Progressive hydrops in ~75% of cases and usually results in fetal demise
Majority of pregnancies w cystic hygroma and dx of Turner syndrome end in stillbirth or IUFD
What is the follow up after identification of cystic hygroma on u/s
Babies may be born with webbed becks or redundant skin-= referral to pediatric sx and/or geneticist
What are shortened long bones
Femur (thigh bones) and/or humerus (bone from shoulder to elbow) length <5th percentile for GA
Fetuses with one of these markers are more likely to have the other as well
What is the incidence for shortened long bones
Femur= 0.3-6%
Humerus= 3.7-7%
What are the associated anomalies and conditions with shortened long bones
DS
Skeletal dysplasias (typically less than 3rd percentile for growth, and additional characteristic signs (fractures, bowing, abnormal cranium shape)
3rd percentile cutoff identifies up to 75% of achondroplasia cases in the 3rd tri
What are the likelihood ratios for shortened long bones
humerus: 5.1-6.3
femur: 1.2-1.5
What are some general risks for fetuses with isolated shortened long bones
Greater risks for IUGR, small for GA, low birth weight (due to placental insufficiency), preterm labor, possibly preeclampsia
What are the testing recommendations following identification of shortened long bones
controversial if amnio is necessary if short femur identified if isolated
shortened humeri less controversial, increased risk for aneuploidy: discuss amnio with chroms, CMA considered
What is the follow up after identification of shortened long bones
serial growth u/s to monitor for placental insufficiency
consider uterine artery Doppler if IUFR is suspected
What is a single umbilical artery/two vessel cord
the most common umbilical cord anomaly. Instead of 1 umbilical vein and 2 umbilical arteries, there is only 1 artery
Thought to be caused by thrombic atrophy of the 2nd umbilical artery
What are some proposed risk factors for development of single umbilical artery
AMA, use of ART, preexisting DM, female fetal gender, chronic HTN, smoking in pregnancy
What is the incidence of single umbilical artery
0.25-2%
Increased in twin pregnancies (4-7%)
Caucasian fetuses 3x more likely to have SUA compared to AA fetuses. Japanese descent are least likely to have SUA
What are the associated anomalies/ conditions with single umbilical artery
when identified in 2nd tri, risk of associated structural anomalies increased to 25-33% (most commonly cardiovascular, genitourinary (renal agenesis, pelvic dilation, hydronephrosis), and vertebral anomalies
Greater incidence of GI anomalies in fetuses with R-sided SUA
If one other anomaly is identified prenatally, risk for aneuploidy (usually T18) increases to 10% (when more than one anomaly is seen, the risk increases to 20-25%)
Other genetic conditions including Meckel-Gruber, VATER, fetal hydantoin syndrome, Zellweger, multiple lentigines, and ectrodactyly syndromes
What are the testing recommendations following identification of single umbilical artery on u/s
In isolated cases, need a high resolution u/s. Prenatal testing/screening not indicated, but can be considered
Dx testing should be offered with additional findings/risk factors (chroms, CMA considered)
What is the follow up following identification single umbilical artery
fetal echo with exams after birth
should be closely followed by pediatrician following IUGR identified for the first 2yrs of life
What are the most common sonographic markers associated with DS (in decreasing likelihood ratio)
Ventriculomegaly (~28), increased nuchal fold/absent or hypoplastic nasal bone (~23), aberrant R subclavian artery (~21), echogenic bowel (~11), mild hydronephrosis (~8%), ICEF (~6), short humerus (~5), short femur (~4)
What is the most common chromosome condition associated with single umbilical artery
T18
What is a choroid plexus cyst typically indicative of on u/s
T18
What is a cystic hygroma typically indicative of on u/s
Turner, Noonan, Heart Defect, Aneuploidy
What is a duodenal atresia (double bubble) typically indicative of on u/s
T21
What is an echogenic bowel typically indicative of on u/s
Bleeding, CF, CMV, T21
What is holoprosencephaly typically indicative of on u/s
T13, SLO
What is 2-3 syndactyly typically indicative of on u/s
SLO
What is a caudal regression typically indicative of on u/s
mat diabetes
What is a cloverleaf skull typically indicative of on u/s
thanatophoric type 2; FGFR2 related disorders (Apert, Pfeiffer, Crouzon
What is a heart and arm anomaly typically indicative of on u/s
Holt-Oram
What is a molar tooth sign typically indicative of on u/s
Joubert syndrome
What is a triad of occipital encephalocele, cystic kidneys, and polydactyly typically indicative of on u/s
Meckel gruber
What is an omphalocele typically indicative of on u/s
BWS
What is Pierre Robin sequence typically indicative of on u/s
Stickler syndrome
What are radial ray anomalies (thumb/radius) typically indicative of on u/s
Fanconi anemia, Holt-Oram, Thrombocytopenia absent radius (TAR) syndrome
What is a rhabdomyoma typically indicative of on u/s
Tuberous sclerosis
What is a telephone receiver femur typically indicative of on u/s
Thanatophoric dysplasia type 1
What is a interrupted aortic arch typically indicative of on u/s
22Q
What is a truncus arteriosus typically indicative of on u/s
22Q
What is tetralogy of Fallot typically indicative of on u/s
22Q, T21
What is heterotaxy typically indicative of on u/s
ciliopathies
What is Ebstein anomaly typically indicative of on u/s
Lithium exposure
What is pulmonary stenosis typically indicative of on u/s
Noonan
What is an ASD/VSD typically indicative of on u/s
T21, T18, T13
What is coarctation of the aorta indicative of on u/s
Turner
What is supravalvular aortic stenosis typically indicative of on u/s
Williams syndrome
What can be seen on u/s in those with arthrogryposis
congenital joint contractures in 2+ areas of the body
What can be seen on u/s in those with Dandy-Walker malformation
primarily impacts the cerebellum
50% have ID
What is a congenital diaphragmatic hernia? What is it associated with?
protrusion of abdominal organs into chest cavity, almost always left-sided
associated conditions: Trisomy 10-20% (mostly 18), Fryns syndrome, Cornelia de Lange syndrome
What is gastroschisis? What is it associated with?
Protrusion of intestines and sometimes other abdominal organs through abdominal wall defect with no protective membrane
opening typically right of the belly button
sporadic, increased incidence among young mothers
What is holoprosencephaly? What is it associated with?
Defect of forebrain cleavage (most severe- alobar; least severe-lobar)
associations with T13, T18, triploidy, single gene (SHH), SLO, Mat DM, alcohol
What is lissencephaly? What is it associated with?
“smooth brain”
Miller-Dieker syndrome, Walker-Warburg
