Ob final study guide Flashcards
Obstetric sonography allows the clinician to assess the ______, ______, and _______ of the fetus.
development
growth
wellbeing
_______ should be performed only when there is a valid medical reason and using the lowest possible ultrasound energy exposure settings
Fetal sonography
The major biologic effects of ultrasound are believed to be _____ and ______ forces.
thermal
mechanical
produced and collapse of gas filled bubbles
cavitation
Sonographer can minimize thermal effects by:
not staying in one place too long
ALARA
as low as reasonably achievable
_____ is a higher ultrasound energy level and should be completed as quickly as possible to reduce thermal effects.
Doppler
_____ is defined as systematic reflection on an analysis of morality. A study of what is good and bad and of moral duty and obligiation.
ethics
A code of ethics for sonographers has been adopted by the:
Society of Diagnostic Medical Sonography
_____ concerns right and wrong conduct and good and bad character. The production of cherished values that related to how a person interacts and lives in peace.
Morality
_______ directs the sonographer to not cause harm.
nonmaleficience
_______ is providing complete information and assuring comprehension
informed consent
_______ by a patient or subject to a required or experimental procedure
voluntary consent
______ is the greater balance of clinical “goods” over “harm. Meaning the exam must be justified and the clinical importance outweighs the possible harm caused by the exam.
Beneficence
______ refers to a person’s capacity to formulate, express, and carry out value based preferences.
autonomy
_______ means truthfulness.
veracity
______ is the adherence to moral and ethical principles.
integrity
______ is the ethical principle that requires fair distribution of benefits and burdens.
justice
______ is the obligation of caregivers to protect clinical information about patients from unauthorized access.
confidentiality
Indications for first trimester sonography
confirm IUP
evaluate suspected ectopic
estimate gestational age
diagnose multiple pregnancies
confirm cardiac activity
as an adjunct to interventional ultrasound guided procedures
interventional ultrasound guided procedures
amniocentesis
chorionic villus sampling
embryo transfer
localization and removal of intrauterine devices
_______ is a midline cranial defect in which there is herniation of the brain and meninges
cephalocele
______ is a rare, lethal anomaly of cranial development. Primary abnormalities include: defect in occiput involving the foramen magnum, retroflexion of the spine, and open spinal defects
ineincephaly
______ is the dilation of the ventricular system without enlargement of the cranium.
ventriculomegaly
______ is a congenital defect caused by an extra chromosome, which causes a deficiency in the forebrain. It is a malformation of the prosencephalon to differentiate into cerebral hemispheres and lateral ventricles between four and eight week.
Holoprosencephaly
______ result in a cystic dilation of the fourth ventricle with dysgenesis or complete agenesis of the cerebellar vermis and frequently hydrocephalus
Dandy-Walker malformation
______ is when the neural tube fails to close after 6 weeks gestation.
spina bifida
The banana sign is associated with _____
spina bifida
The lemon sign is associated with _____
scalloping the frontal bones
Abnormal wall defects
bowel herniation
gastroschisis
omphalocele
appears sonographically as an echogenic mass at the base of the cord between 8 and 12 weeks
bowel herniation
Bowel protrusion outside of the abdominal wall. Congenital fissure that remains open past 12 weeks in the wall of the abdomen just to the right of the umbilical cord
gastrochisis
abdominal wall defect where the liver, bowel, and stomach are typically located in the umbilical cord. Cannot be differentiated from normal physiological bowel migration until after 12 weeks
omphalocele
The fetal bladder is seen as __-__ weeks of gestation
10
12
________ is seen as a very large bladder because the obstruction does not allow the bladder to empty properly
obstructive uropathy
_______ is fluid filled structure of the with septations that typically surrounds the neck but may extend upward to the head or laterally to the body. it is one of the most common abnormalities seen sonographically in the first trimester
cystic hygroma
Cystic hygroma is associated with chromosomal abnormalities and most common are:
trisomy 13, 18, 21
In fetuses detected with cystic hygroma in the second and third trimesters, _______ is the most common karyotype abnormality
Turners syndrome
The ______ cyst is the most common ovarian/pelvic mass seen in the first trimester of pregnancy
corpus luteum
A gestational sac without an embryo may present:
a normal early IUP
abnormal IUP
pseudogestational sac in a patient with an ectopic pregnancy
________ , is a gestational sac in which the embryo fails to develop or stops developing at an early stage
anembryonic pregnancy
anembryonic pregnancy is also known as:
blighted ovum
__________ is when trophoblastic tissue overtakes the pregnancy and propagates throughout the uterine cavity.
gestational trophoblastic disease
Sonographic findings of Gestational Trophoblastic Disease
snowstorm appearance caused by hydatidform mole
cluster of grapes
increased blood flow
Embryonic bradycardia
<90 BPM
Embryonic tachycardia
> 170 BPM
The amnion is best visualized transvaginally between the __ and __ week
5
7
Ectopic pregnancy is located outside the _______/_____ portion of the uterus.
central/fundal
One of the most emergent sonographic diagnoses
ectopic pregnancy
Approximately __% of maternal deaths are related to ectopic pregnancy.
10
Ectopic pregnancy occurs in the _______ in 95% of cases.
fallopian tubes
________ is simultaneous intrauterine and extrauterine pregnancy.
heterotopic pregnancy
_______ is in the fallopian tube at the cornua of the uterus
Interstitial
______ is the most life threatening kind of pregnancy because this area contains the parauterine and myometrial vasculature increasing the risk of massive hemorrhage.
interstitial pregnancy
_______ is when the gestational sac is within the cervix
cervical pregnancy
_______ frequently presents on ultrasound as an _______ shaped uterus
hourglass
______ is when the pregnancy is within the ovary
ovarian pregnancy
The maximum thickness of the subcuteaneous lucency at the back of the neck in an embryo at 11-14 weeks
nuchal translucency
Markers for cardiac anomalies
increased nuchal translucency
tricuspid regurgitation
reversal of flow in the ductus venosus
The partial or complete absence of the cranium
acrania
the congenital absence of the brain and cranial vault
anencephaly
By 8 weeks 3 primary vesicles seen within fetal brain
prosencephalon
rhombencephalon
mesencephalon
Around 20 weeks of gestation, a sonogram may demonstrate a cystic area within the cranium which is the ______
normal rhombencephalon
By 9 weeks the _____ has formed and the echoigenic _____ tissue is seen in the lateral ventricles
midline falx
choroid plexus
Limb buds are recognizable during the __ week of gestation
6th g
Hands and feet decelop later in the first trimester and completely formed the the end of the __ wek
10th
At __ weeks calcifications of the clavicle begins, floowed by ossification of the mandible, palate, vertebral column, and neural arches
8
Frontal cranial bones begin to calcify at __ weeks followed by long bones
9
Palate fusion occurs late in the ____ trimester.
first
____ and ____ are noted brightly echogenic structures by the 9th week
maxilla
mandible
Abdominal wall is developed by __ weeks of gestation
6
Midgut descends into the fetal abdomen at about __ weeks
11
Embryonic hear beat starts beating at approximately __ days
23
Normal heart rate 5 weeks
92-109 BPM
Normal heart rate 6 weeks
112-136 BPM
Normal heart rate 7 weeks
112-140 bpm
normal heart rate 8 weeks
126-160 BPM
Normal heart rate 9 weeks
126-150 BPM
Normal heart rate 10 weeks
126-150 BPM
Normal heart rate 11 weeks
120-150 BPM
Normal heart rate 12 weeks
125-160 BPM
Dizygotic twin pregnancies account for __% of all twins
70
Dizygotic twins are defined as _____ and _____
dichorionic
diamniotic
______ twin arise from two separately fertilized ova.
dizygotic
_____ and _____ twins appear as two separated gestational sacs
dichorionic
diamniotic
_________ twins appear to be contained within a single gestational/chorionic sac; two amnions; two yolk sacs, and two embryos are identified.
Monochorionic-diamniotic
___________ twin gestation is one gestational sac, one yolk sac and one amniotic membrane and two embryos within a single amniotic cavity.
monoamniotic-monochorionic
multiple pregnancies with chorionic sac
monochorionic
Most common presentation for complications in the first trimester is ______
bleeding or spotting
Most common reason for bleeding in the 1st trimester
subchorionic hemorrhage
Secondary yolk sac is formed at ___ days when the primary yolk sac is pinched off by the extra embryonic coelom
23
The embryonic phase is week __ through week __
4
10
During the _____ phase all the major internal and external structures begin to develop
embryonic
______ is the most accurate measrement for determining gestational age.
crown rump length
The crown length measurement is considered the most accurate through the __ week.
12
In early pregnancy, the gestational sac size grows at a rate of __ mm/day
1
An embryo with cardiac activity should be identified transvaginally when the gestational sac measures __-__ mm
16-20
Mean sac diameter formula
length + width + height/3
Initial heart beat occurs between __ - __ weeks
5.5
6
Ectopic pregnancies demonstrate a ____ hCG than intrauterine pregnancies
lower
The serum leve3l of beta hCG is dramatically elevated with ______
gestational trophoblastic disease
hCG is normal 7 week pregnancy doubles every ___ days
3.5
A normal gestational sac can be consistently demonstrated with transabdominal scanning when the beta hCG level is ____ mIU/ml
1800
AT __-__ weeks hCG levels plateau and subsequently decline while gestation continues
9
10
In ______ hCG levels are increased and they plateau much later and fall much more slowly
trisomy 21
Intrauterine pregnancy can be visualized sonographically during the __ week
fifth
______ is on the myometrium or burrowowing side of conception
decidua basalis
the interface between the decidua capsularis and the echogenic, highly vascular endometrium
double decidual sac sign
_____ is the earliest intragestational sac anatomy seen
yolk sac
_____ is usually seen from 5 weeks gestation
yolk sac
Visualization of the _____ predicts a viable pregnancy
yolk sac
