fetal structural abnormalities

ob week 4

what are orbits

eyeballs

what plane is fetal orbit assessment taken in, and what position should baby be in

taken in axial/transverse plane

baby should be supine

what do you look for in fetal orbit assessment

bilateral development

equal size and spacing

width between orbits roughly the same size as orbits

what is hypotelorism

orbits spaced closer than normal

what is associated with hypertelorism

holoprosencephaly

trisomy 13

microcephaly

hypertelorism

orbits being spaced farther than normal

what is hypertelorism associated with

trisomy 18

anterior cephaloceles

teratogen exposure

what is anopthalmia

absence of globe and sometimes orbit

what causes anopthalmia

failure of optic vesicle to form

what is anopthalmia associated with

Goldenhar-Gorlin syndrome

how do you assess the nose and lips

move transducer forward from the coronal orbital view

image demonstrates two nostrils and separate upper lip

if you are able to assess the nose, upper lip, lower lip and chin in the same plane, what does that mean

that baby is negative for micrognathia

what plane is the palate assessed in

transverse

what structures should be visible in the picture assessing for hard palate

upper lip

hard palate

why do we check the hard palate

to demonstrate intact skin line of upper lip and intact palate

what plane do we check mandible in

transverse

what structures should be visible in the mandible assessment picture

lower lip

jaw

why do we check the mandible

to demonstrate intact lower jaw line

what is the most common facial abnormality

cleft lip and palate

why does cleft lip and palate occur

failed fusion of maxilla, primary + secondary palate

amniotic bands

what are the two major groups of cleft palate

upper lip + anterior maxilla with or without hard palate involvement

cleft resulting from lack of fusion of maxillary prominence with nasal prominence

what is cleft lip and palate associated with

trisomy 13

CNS anomalies

teratogens

amniotic band syndrome

what limitations does sonography have in diagnosing cleft palate

cannot assess for cleft soft palate

how does cleft lip appear on ultrasound

anechoic gap in upper lip seen on coronal views of lip and nose

what other abnormal findings can we find in association with cleft palate

polyhydramnios

small stomach

swallowing issues

why is 3d ultrasound especially helpful in cleft palate cases

allows visualization of posterior portion of palate

demonstrates surface of fetal face

what would color doppler show in cases of cleft palate

fluid flow through cleft

what is micrognathia

hypoplastic mandible

small chin

what is micrognathia associated with

trisomy 18.

pierre robin sequence

Goldenhar-Gorlin syndrome

how does micrognathia appear on ultrasound

in saggital view of facial profile:

protrustion of upper lip

small chin

what is macroglossia

persisent protrusion of tongue

what is macroglossia associated with

beckman wiedman syndrome

hypothyroidism

how does macroglossia appear on ultrasound

tongue protrudes beyond alveolar proccess

what is cylcopia

midline fusion of orbits

single orbit

blind proboscis

what is blind proboscis

protrusion of nasal tissue above orbit

what is cyclopia associated with

holoprosencephaly

teratogen exposure

how does cyclopia appear on ultrasound

extreme hypotelorism or transverse view

demonstration of proboscis on saggital profile view

what is MSAFP

maternal serum alpha fetoprotein

greater than 2.5 multiples of the median (MoM) may suggest what abnormality

neural tube defect

why is MSAFP elevated in neural tube defects

the membranous covering over neural tube defect allows excess AFP to enter maternal circulation

what does increased fundal height suggest

raises suspicion of polyhydramnios

why does polyhydramnios occus in NTD

NTD can impair fetal swallowing allowing fluid to accumulate

what does a lemon shaped head indicate

bilateral indentation of frontal bones

what is a lemon shaped head associated with

spinda bifida

what is a strawberry shaped head

flattened occiput and narrowing of frontal part of head

what is strawberry shaped head associated with

trisomy 18

what is brachycephaly

shortened broad head

CI greater than 85%

what is brachcephaly associated with

chromosomal abnormalities

what is dolichocephaly

long, narrow head

long occiptal-frontal distance

CI less than 70%

what is dolichocephaly associated with

typically due to head molding in breech presentation

what is ventriculomegaly

ventricular enlargement with excessive CSF within ventricles

what is ventriculomegaly associated with

obstruction to outflow

decreased CSF absorption

overproduction of CSF

what is hydrocephalus

ventricular enlargement secondary to increased intracranial pressure / head enlargement

measurement of atrium of lateral ventricles should not exceed __

10mm

where do you measure lateral ventricle

transaxial plane above BPD plane

what should the lateral ventricles contain

choroid plexus

what fluid is contained within lateral ventricles

CSF

what is the normal prognosis of ventriculomegaly

depends on associated abnormalities

what is ventriculomegaly associated with

mostly CNS defects

cardiac malformations

renal malformations

how does ventriculomegaly appear sonographically

excess fluid in lateral and third ventricle

atrium of lateral ventricle measuring greater than 10mm

dangling choroid plexus

what are associated sonographic findings of ventriculomegaly

polyhydramnios

abnormal fetal lie

hepatomegaly

fetal ascites

meningomyelocele

what is acrania

absent skull bone , present brain

how does brain develop in acrania cases

usually abnormal, and shows signs of atrophy

what is anencephaly

absence of skull and cerebral hemispheres

what features may be seen in anenecephaly

bulging eyes

macroglossia

short neck

high AFP

how does anencephaly present sonographically

major portions of cranium and intracranial are absent

“frog-like” face

polyhydramnios

talipes

what is talipes

club foot

what can happen if there is a bony defect in the skull

herniation of intracranial contents

what is a cranial meningocele

herniated contents only includes meninges and CSF

what is encephalocele

herniation of contents include brain tissue and CSF

what are the classifications of enecephalocele or cehpalocele

occipital

frontal

parietal

how does encephalocele or cephalocele present sonographically?

tends to be asymmetrical

mass extending from calvarium

evident cranial defect

cranial cavity appears small

what is holoprosencephaly

incomplete cleavage of primitive forebrain into 2 hemispheres

holoprosencephaly has a strong association with

trisomy 13

how is holoprosencephaly classified

alobar

semilobar

lobar

what is the most severe form of holoprosencephaly

alobar, typically lethal

what is alobar holoprosencephaly

lacking 2 hemispheres

large single ventricle with minial surrounding cerberal tissue

what is semilobar holoprosencephaly

single ventricle

occipital or temporal horns may be present

what is lobar holoprosencephaly

least severe form

2 hemispheres are present

absence of cavum septum pellucidum and corpus callosum

how does holoprosencephaly appear sonographically

fetal cranium appears to have large midline cystic spaces

absence of falx and corpus callosum

facial anomalies

what is dandy walker complex (DWM)

congenital malformation of posterior fossa

small / absent cerebellar vermis

what is vermian hypolasia

abnormal vermian development

midline of cerebellum

what is associated with DWM

CNS abnormalities

how does DWM present sonographically

complete/partial agenesis of cerebellar vermis

enlargement of the 4th ventricle

enlarged cisterna magna

what is arnold chiari type ii malformation

displacement of cerebellar vermis, 4th ventricle, and medulla oblongata

how does arnold chiari type ii malformation appear sonographically

cerebellum will be compressed against back of cranium in c shape

banana sign

no cisterna magna

ventriculomegaly

what is microcephaly

small head circumference (more than three standard deviations below normal)

what is microcephaly associated with

intrauterine infection

aneuploidy

CNS anomaly

how does microcephaly occur

small BPD

decreases HC/AC ration

poor cranial growth