Week 11- DMS 212 Fetal Head, Neck, and Spine

AFP is produced by the fetal ____________ and ________________

liver and yolk sac

AFP is found in the...

maternal serum and amniotic fluid

AFP peaks at ___________ weeks

15-18

elevated AFP can indicate

underestimated ges age

multiple fetuses

open neural tube defect

abdominal wall defect

cystic hygroma

fetal demise

low AFP can indicate

overestimated ges age

chromosomal abnormality

GTN

long-standing demise

maternal HTN or diabetes

when is the maternal AFP test taken

15-17 weeks

example of neural tube defect

spina bifida

example of abdominal wall defect

omphalocele

in the early 1st trimester most of the amniotic fluid comes from the _____________

maternal blood

later in the 1st trimester amniotic fluid comes from the ___________________

fetus excreting urine

how is amniotic fluid created

fetus swallowing the fluid and urinates it

when does the ability to swallow begin

8-11 weeks

swallowing the fluid helps to develop the __________________ system

GI

inhaling small amounts of fluid helps to develop the _______________ system

respiratory

keritization

exchange of fluid through permeable fetal skin

urine output accounts for nearly ________________ of fluid in the second half of pregnancy

total volume

after _______ weeks the fetus becomes the major producer of the amniotic fluid

16

quantity of fluid is directly related to _____________ function

kidney

if there is a renal anomaly you might expect to see

oligohydramnios

functions of the amniotic fluid

protection

temp reg

enables fetal movement

lung and genitourinary development

polyhydraminos

too much fluid

polyhydraminos is assoc with

TTTS

oligohydramnios

too little fluid

anhydramnios

no fluid

sono appearance of anhydramnios

no window to see baby

from __________weeks there will be a generous amount of fluid

20-30

volume of fluid stops increasing at _______ weeks

33

when does fluid become scanty

late third trimester

how is AFI determined

in the maternal sag plane four quadrants of fluid are measured

AFI of oligohydramnios

less than 5cm

largest single pocket less than 2cm

AFI of polyhydramnios

more than 24cm

largest single pocket more than 8cm

cephalic presentation

head down toward cervix

breech presentation

head up

transverse lie maternal right

head toward right

transverse lie maternal left

head toward left

complete breech

both knees bent feet down

incomplete breech

one leg up one leg down

frank breech

both legs up

oblique presentation

head and body are 45 degrees angle to the maternal sag plane

how many bones are in the feta head

8

the fetal head bones are connected by

sutures

________________________ exist between the forming bones

fontanelle spaces

abnormal head shapes can develop because

bones of the skull are moveable and malleable

fontanelles ramin unossifies through the __________ of life to allow...

1st year, vaginal delivery and expansion of growing brain

what are the forces that can cause a mishappen head

external pressure

gravitational forces

early fusion

plagiocephaly

uneven shaped forehead

trigonocephaly

triangular shaped forehead

scaphocephaly

long narrow head

scaphocephaly is caused by

craniosynostosis

brachycephaly

short wide head

dolichocephaly

Long narrow head

dolichocephaly is caused by

pressure or premature fusion of sagittal suture

what are the two divisions of the fetal head

cerebrum

posterior fossa

the cerebrum contains the

interhemispheric fissure

falx

corpus callosum

CSP

thalamus

ventricular system

corpus callosum

provides communication between the two hemispheres

location cavum septum pellucidum

between the frontal horns of lateral ventricles

location of thalamus

either side of the third ventricle

function of the ventricular system

cushioning for the brain

the ventricular system contains the _______________

choroid plexus

choroid plexus function

produces CSF

echogenicity of the choroid plexus

echogenic

choroid plexus cysts

isolated

contain CSF

resolve between 24-26 weeks

measurement of the lateral ventricles

less than 10mm

location of the 3rd ventricle

slit between lobes of the thalamus

posterior fossa

cerebellum

cisterna magna

forth ventricle

the cerebellum grows ______mm per week between _________ weeks

1, 14 and 20

shape of the cerebellum

figure 8

where is the cerebellum measured

level of cisterna magna and thalamus

what is the banana sign

cerebellum is banana shaped

brian is being pulled down into spinal canal

normal measurement of cisterna magna

3-10mm

normal measurement of nuchal fold

less than 6mm

when is the nuchal fold identified

17-20 weeks

thickened nuchal fold indicated

down syndrome

trisomy 21

when is NT measured

11-13.5 weeks

normal measurement of NT

2.5-3mm

equal sign

top- skin

bottom- nasal bone

level of BPD, HC, and OFD

falx

CSP

thalami

CI of dolichocephaly

less than 75

CI of brachycephaly

more than 85

normal CI

80

when do the nasal bones first appear

11-13 weeks 6 days

CRL of 42mm

why is the nose/lips view so important

to rule out cleft lip/palate

anophthalmia

absence of one or both eyes

colpocephaly

migrational defect of the occipital horns of the lateral ventricles leading to ventricular enlargement

dysgenesis

abnormal formation

dysmorphic

Malformation of an organ or structure

ectasia

dilation or distension of hollow structure

nares

nostrils

neuropore

rostral or caudal end of neural tube

rostral

toward the head

teratogen

anything that interferes with development

vermis

central portion of cerebellum assoc with posture and locomotion

maternal serum AFP ________________ across placenta

diffuses

anencephaly

no cranium or brain tissue

sonographic features of anencephaly

abnormally shaped cephalic pole

absent neural tissue

loss of normal head contour

froglike appearance

spinal defects

omphalocele

clubfoot

cleft lip/palate

polyhydramnios

agenesis of corpus callosum (ACC)

complete or partial albescence of corpus callosum

ACC is assoc with

trisomy 13 and 18

hydrocephalus

dandy-walker syndrome

arnold-chairi malformation

holoprosencephaly

dandy-walker syndrome

absence of cerebellar vermis and enlarges 4th ventricle

lemon sign

frontal deformities assoc with arnold chiari malformation

growth of long bones is from __________________ to ______________________

proximal to distal