OB: Section I. Obstetric Sonography 3/6

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Estimated date of delivery (EDD)

due date, calculated by adding 280 days to the first day of the last menstrual period; also called estimated date of confinement (EDC).

Conceptual age

duration of pregnancy, counted from fertilization, expressed in hours or days, also called embryonic age or post ovulatory age.

Gestational age (GA)

duration of pregnancy, counted from the first day of the LMP, expressed in weeks and days or fractions of weeks. A pregnancy usually lasts 280 days, or 40 weeks.

Missed abortion

early failed pregnancy that remains in the uterus

Blastocyst

early gestation consisting of a thin outer layer of cells (trophoblast), a fluid-filled cavity, and an inner cell mass (embryoblast).

fetal stage begins following the

embryonic period after about 11 weeks

Blighted ovum

empty gestational sac seen in an embryonic pregnancy

Hyperemesis

excessive vomiting during pregnancy sometimes called hyperemesis gravidarum

Inevitable abortion

failed early pregnancy that is in process of being expelled from the uterus

what assists the ova to move into and through the fallopian tube?

fimbriae, contractile walls, and celia. NOT: infundibulum

Gestational sac

first sonographic evidence of an intrauterine pregnancy, the fluid-filled blastocyst.

Hydatidiform mole

form of gestational trophoblastic disease resulting from abnormal fertilization in which there is proliferation of swollen chorionic villi. Also called a molar pregnancy.

Estrogen

group of hormones, primarily produced in the ovaries, which affect secondary sex characteristics and menstrual cycle.

ultrasound in the fisrt trimester is mostly used to demonstrate

hCG level and CRL

Gamete

haploid cell that, when merged with a gamete from the opposite sex, creates a diploid zygote.

gametes are..

haploid cells with 23 chromosomes

Progesterone

hormone produced by the corpus luteum and the placenta

Human chorionic gonadotropin (hCG)

hormone produced by trophoblast cells of the blastocyst, which extends the life of the corpus luteum in the ovary; most pregnancy tests are based on this

Molar pregnancy

hydatidiform mole

Gestational trophoblastic neoplasia

invasive or metastatic form of gestational trophoblastic disease.

Amniocentesis

invasive procedure in which a quantity of the amniotic fluid is removed from the amniotic sac for analysis of the fetal cells or for presence of certain chemicals in the fluid itself; may also be performed as a palliative measure in patients with severe polyhydramnios.

Chorionic villus sampling

invasive procedure in which the chorionic villi of an early pregnancy are removed for analysis

Theca-lutein cysts

large, often bilateral ovarian cysts, the formation which is usually stimulated by excessive levels of circulating human chorionic gonadotropin (hCG).

which hormone triggers ovulation

luteinizing

the placenta will mature from early pregnancy to release all but the following

luteinizing hormone

Crown-rump lenght (CRL)

measurement of the longest axis of an embryo to determine gestational age

Chorion

membrane around the chorionic cavity, made up of trophoblast cells and extraembryonic mesoderm.

Amnion

membrane enclosing the amniotic cavity and embryo or fetus

the whip-like tail of the sperm contains,

mitochondria

a cluster or ball of forming cells is a?

morula

the head of sperm cells contain...

nucleus, which house enzymes allowing for penetration of the outer layer of the ovum.

Anembryonic pregnancy

pregnancy that has fail prior to the development of an identifiable embryo or in which embryonic tissue has been resorbed after early embryo demise

Follicle-stimulating hormone (FSH)

produced by the anterior pituitary, which stimulates the maturation of ovarian follicles.

Luteinizing hormone (LH)

produced by the anterior pituitary, which triggers ovulation in females.

Conceptus

product of fertilization, including all stages from zygote to fetus.

a ruptured follicle, or corpus lutem releases

progesterone

Corpus luteum

progesterone-secreting structure formed by a follicle after releasing its oocyte.

the 5 brain vesicles, which will become the lateral ventricles, the 3rd ventricle, and the upper and lower parts of the 4th ventricle, and the connections between them develop from the

prosencephalon and rhombencephalon

Pregnancy-associated plasma protein A (PAPP-A)

protein produced by the trophoblasts; abnormal levels of PAPP-A may be associated with increased risk of chromosomal abnormalities

zygote

singe cell resulting from the fusion of two gametes.

once the ovum is fertilized, the structure is called a ..

single diploid cell, conceptus, or the zygote

Morula

solid cluster of undifferentiated cells formed by repeated cleavage of the single cell that resulted from the fusion of two gametes.

Gestational trophoblastic disease

spectrum of disorders that begin at fertilization and involve abnormal proliferation of the trophoblasts that in a normal pregnancy form the placenta; may become invasive, malignant, and metastasize.

Miscarriage

spontaneous failure and expulsion of an early pregnancy.

Umbilical vesicle / Yolk sac

structure within the cavity of the blastocyst, which provides nourishment to the embryo and produces its first blood cells; the secondary umbilical vesicle (yolk sac) is the first structure to be sonographically identified within the gestational sac.

Nucal translucency (NT)

subcutaneous fluid in the posterior region of the neck of embryos and fetuses up to 14 weeks' gestational age; abnormally large NTs have been associated with a higher risk of chromosomal and structural abnormalities.

the double sac sign is developed by two layers of deciduas:

the decidua capsularis and the decidua parietalis

the amniotic cavity is formed within the

tick epiblast, adjacent to the trophoblast.

the first blood cells in the embryo are produced by the

umbilical vesicle and are transferred to and from through the vitelline veins and arteries.

what prevents more than one sperm entering an ovum?

zona pellucida

implantation of the blastocyst cannot happen until the

zona pellucida disintegrates.

nourishment from the endometrial glands crosses the

zona pellucida, enter the morula, and forms a fluid-filled cavity called the blastocyst.

the endometrial layers are

a thin basal layer adjacent to the myometrium and functional layer of connective tissue.

Complete hydatidiform mole

abnormal fertilization of an oocyte that contains no maternal chromosomes, resulting in the proliferation of swollen chorionic villi and the absence of identifiable embryonic structures.

Partial hydatidiform mole

abnormal fertilization resulting in one maternal and 2 paternal sets of chromosomes (triploidy), leading to the development of an abnormal fetus and placenta.

Tachycardia

abnormally rapid heart rate.

Bradycardia

abnormally slow heart rate.

At what age have the rudimentary forms of all embryonic organs and structures developed?

almost 11 weeks menstrual/gestational age.

Acrosome

area located in the head of the sperm containing enzymes to aid in penetration of the oocyte.

Mean sac Diameter (MSD)

average diameter of the gestational sac, used to determine gestational age.

a blastocyst consists of all of the following:

blastocele, trophoblast, and embryoblast. Except: blastocite

Chorion Villi

budlike outward growths, counted from the trophoblast cells and extraembryonic mesoderm

Decidualization

changes in the endometrium to allow implantation of a blastocyst.

the first structure seen sonographically within the uterus in early pregnancy is the

chorionic sac

24 to 30 hours after fertilization, rapid cell division occurs. It is known as

clevage

Subchorionic hemorrhage

crescent-shaped sonolucent collection of blood between the gestational sac and the uterine wall.

prepatory changes in the endometrium allowing for implantation include

decidualization

the portion of the endometrium related to blastocyst attachment is the?

deciduas basalis

fetal placenta occupies the

deciduas basalis portion of the endometrium, leaving the basal layer intact.

the yolk sac becomes part of the embryonic gut and contributes to:

digestive, respiratory, and urogenital development

sonography may detect a blastocyst embedded in the decidua as early as

11 days after conception

what is the normal resting heart rate of a 3rd trimeter fetus?

110 to 160 beats per minute.

Second trimester

14 weeks to the end of the 27 week

spontaneous pregnancy loss usually happens in the

1st trimester

a 5 week yolk sac measures about

2.3 millimeters in diameter and enlarges to 5.6 mm at 11 weeks, then disappears by 12 weeks gestational age.

Third trimester

28 weeks to delivery

a normal gestation lasts approximately

280 days

the first visualized structure within the gestational sac is the

2nd yolk sac

the embryonic disc contains

3 germ cell layers from which all future organs and tissue is derived.

the developing cluster of cells travels through the fallopian tube and reaches the uterus about

4 days after fertilization.

the most accurate measurement for dating in early pregnancy is the

CRL

At which gestational age does the yolk sac image between the chorion and amnion?

Carnegie stage 20

Which brain structure can be identified in this sonogram?

Choroid plexus

Where does implantation of the embryo occur?

Endometrium

What hormone does the mature ovarian follicle secrete?

Estradiol

the pituitary produces ..

FSH, which at puberty causes follicles to mature and fill with fluid

Which of the following is the solid ball of developing cells that occurs after fertilization?

Morula

when the nuchal translucency (NT) measurement is combined with

PAPP-A and free B-hCG, the detection rate for trisomy 21 increases to 86%

CHAPTER 14 ------------------------------------------------

SONOGRAPHIC EVALUATION OF 1ST TRIMESTER COMPLICATIONS

First timester

0 days (LMP) to the end of the 13th week

ultrasound measurement errors due to beam width and machine calibration of

1 or 2 mm per 10 cm are acceptable

3 criteria for interstitial pregnancy are:

1, An empty uterine cavity. 2, A gestational sac greater than 1 cm from the most lateral point of the endometrial cavity. 3, A gestational sac surrounded by a thin myometrial layer.

at what level of b-hcg concentration should a normal intrauterine pregnancy be seen?

1,500 to 2,500 mIU/mL

spontaneous pregnancy loss before 20 weeks occurs in approximately what percentage of population?

10 to 20%

the placenta can be well documented as a discoid structure transabdominally at

12 weeks

what percent of pregnancies in the US are ectopic?

2%

a gestational sac without an embryo or yolk sac with a mean sac diameter greater than

2.0 cm generally predicts pregnancy failure

Using the Jeanty table, what is the BPD measurement range for a 15 week fetus? (For this item, use table in the textbook.)

2.2 to 2.5 cm

tubal rupture occurs in

21% of ectopic pregnancies

to estimate an accurate fetal age, the BPD measurements should be obtained before:

33 weeks

Nuchal cord

360 degree wrapping of the umbilical cord around the fetal neck.

Using the Hadlock table, what is the gestational age for a fetus with a head circumference of 342.7 millimeters? (For this item, use table in the textbook.)

39.1 weeks

How many days long does the ovulation period last?

4 days

the normal duration of pregnancy is

40 weeks from LMP

measurement errors occur as many as

45% of fetuses in the circumstance of external uterine pressure with the BPD measurement.

B-hCG levels should double approximately every:

48 hours

In a normal pregnancy, how long does it take the B-hCG to double?

48 hours

a typical placenta weights

480 to 600 gams

transvaginal sonography should demonstrate a fetal pole with cardiac motion at

5.5 to 8 weeks of gestation

generic abnormalities cause

50 to 70% of pregnancy failures

what percent of patients with ectopic pregnancy have no symptoms?

50%

indications of possible embryonic demise:

6 mm embryo without cardiac activity. No double bleb sign with a < 5 mm embryo. Enlarged amniotic sac with < 5 mm embryo.

when are ectopic pregnancies usually diagnosed?

6 to 10 weeks

the implantation window begins

6 to 8 days after ovulation and lasts for approximately 4 days.

what b-hcg levels are necessary to visualize an IUP using transabdominal approach?

6,500 mIU/mL

CHAPTER 18 ----------------------------------------------

ABNORMALITIES OF THE PLACENTA & UMBILICAL CORD

CHAPTER 16 ------------------------------------------

ASSESSMENT OF FETAL AGE & SIZE OF THE 2ND & 3RD TRIMESTER

Which of the following defines a heterotopic pregnancy?

An intrauterine pregnancy (IUP) coexisting with an ectopic pregnancy

Which type of resolution is half of the spatial pulse length?

Axial

the most exact orbit measurement is the

BOD

the most common and routine measurement to assess the fetal growth and well being are

BPD, HC, AC and FL

common fetal body ratios are

BPD/FL, HC/AC, and AC/FL

select the correct CI formula

BPD/FOD X 100

Which of the following terms describes an oocyte without maternal chromosomes resulting in proliferation of swollen chorionic villi and the absence of identifiable embryonic structures?

Complete hydatidiform mole

What anatomy is indicated by the arrows?

Double sac sign

the fetal expected birth date is known as the

EDC or the EDD

Which phase of pregnancy provides the most accurate dating?

Early embryo measurements

Which of the following best defines the sonographic appearance for an inevitable abortion?

Empty low-lying gestational sac, open cervix.

Which of the following is the most commonly used measurement to estimate fetal age?

FL

Marcrosomia

Fetus over 4,000 grams (8 lb, 13 oz)

Which of the following is the differential for an intraplacental lesion?

Fibrin deposition

What is the most likely cause for the sonographic visualization of hypoechoic areas in the intervillous spaces beneath the chorion that lack flow?

Fibrin deposits

Which maternal factor results in delayed placental maturation of a five centimeter placenta?

Gestational diabetes

signs of tubal rupture may include all of the following:

Hypotension. Rebound tenderness. Tachycardia. Except: urinary tract infection

Which of the following placental greases demonstrates basal and interlobular septal calcifications?

III

Which type of ectopic pregnancy implants on previous cesarean scars?

Intramural

Which form of placenta previa lies within two centimeters of the internal cervical os?

Low-lying placenta

Which hormone triggers ovulation?

Luteinizing

which is the only procedure that does not require ultrasound guideance

MCA doppler

gold standard modality for diagnosing and locating abdominal ectopic pregnancies

MRI

select the measurement not usually included in a first trimester screening for assessing risk in a chromosomally abnormal fetus.

MSD

marginal cord insertion in sonograpic image

Marginal

Which of the following is the spontaneous failure and expulsion of an early pregnancy?

Miscarriage

Which of the following is the structure indicated by the arrow?

Omphalocele

What is the most likely cause for the sonographic finding on a 26- year-old, G2P1, patient presenting with complaints of pain and bleeding with a high risk history due to uncontrolled hypertension and a previous sonographic examination?

Placenta abruption

Which of the following is the implantation of the placenta low in the uterus resulting in total or partial covering of the cervix?

Placenta previa

Predictive value

Precision rate or the probability of disease.

Which acquired maternal problem results in a placenta thickness of less than two centimeters?

Preeclampsia

What is the area between the myometrium and placenta?

Retroplacental

CHAPTER 15 ---------------------------------------

SONOGRAPHIC ASSESSMENT OF THE ECTOPIC PREGNANCY

CHAPTER 17 ------------------------------------------

THE FETAL ENVIRONMENT

CHAPTER 13 --------------------------------------

THE USE OF ULTRASOUND IN THE 1ST TRIMESTER

Which term describes an abnormally fast heart rate?

Thachycardia

What anatomic landmarks help determine the correct level to measure the HC?

Thalamus, falx, cavum septum pellucidum

Which of the following is a chromosomal cause for a thick placenta?

Triploidy

Which of the following describes the sonographic characteristic of excessive Wharton's jelly?

Variably echogenic, soft tissue mass with three vessels visible.

Which of the following term describes the mucous tissue surrounding the umbilical cord?

Wharton's jelly

A pseudosac is

a fluid collection caused by bleeding form the decidualized endometrium

if ultrasound is equivocal in the diagnosis of ectopic pregnancy:

a laparoscopy may be used for diagnosis

routine obstetric ultrasound done between approximately 6 and 12 weeks divulging a normal singleton fetus demonstrates

a miscarriage rate of 1.6%

color doppler presents as

a ring of fire around a viable ectopic pregnancy

a pregnancy less than 20 weeks with vaginal bleeding is termed

a threatened abortion

which ectopic pregnancy location can support a pregnancy the longest before detection?

abdominal

symptoms of general malaise, nausea, vomiting, vaginal bleeding, and painful fetal movements are associated with

abdominal ectopic prenancy

Placenta accreta, increta, and percreta

abnormal attachment of the placenta to the uterus with different terms used to describe the depth of placental invasion

hydatidiform moles are caused by;

abnormal fertilization

Placenta hydrops

abnormal fluid accumulation coexisting with fetal hydrops

Aneuploidy

abnormal number of chromosomes

an endometrial stripe thickness less than 8 mm suggests an

abnormal or ectopic pregnancy

Circumvallate placenta

abnormally attached placenta with a peripheral raised ring

the sliding sac sign suggests an

abortion in progress

What is the mIU/mL discriminatory cutoff for B-hCG.?

above 1,500 to 2,500

sonography can detect central nervous system abnormalities, such as

acrania/anencephaly, spina bifida, encephalocele, holoprosencephaly, and Dandy-Walker malformation.

the most accurate fetal measurements are taken

along the beam axis using the axial resolution

fertilization generally occurs in the ..

ampullary portion of the fallopian tube.

most ectopic pregnancies occur in the

ampullary portion of the oviduct.

if the fetal head is very low in the pelvis,

an endovaginal transducer may allow BPD measuements

b-hcg levels increase and then plateau at

approximately 9 to 11 weeks

Retroplacental

area between the myometrium and placenta

extrachorial placenta

attachment of the placental membranes to the fetal surface of the placenta rather than to the underlying villous placental margin

an aborting gestational sac will appear

avascular with color doppler

accurate measurements are partially determined by

axial and lateral image resolution

Annular placenta

bandlike placenta encircling the internal uterus

False knot

bending, twisting, and bulging of the umbilical cord vessels mimicking a knot in the umbilical cord.

B-hCG

beta human chorionic gonadotropin; a glycoprotein hormone produced in pregnancy that is made by the embryo soon after conception and later by the placenta

macrosomia is defined as a

birth weight 4,000 grams or higher

select a fetal characteristic that is not a 3rd trimester individuation

bradycardia

the femur measurement

can be reliably used after 14 weeks gestation

Braxton-Hicks

cause bulging into the amniotic cavity

MTX, known as methotrexate, interferes with

cell division and is used to manage ectopic pregnancy in a conservative manner

Omphalocele

central anterior abdominal wall defect of the umbilicus where abdominal organs are contained by a covering membrane consisting of peritoneum, Wharton's jelly, and amnion

a normal cord insertion is called

central insertion

What is the most likely diagnosis for the sonographic appearance of a circumscribed complex mass protruding from the fetal surface of the placenta?

chorioangioma

theca lutein cysts are usually stimulated by excessive levels of hCG and are related to:

complete molar pregnancy

a ruptured tubal pregnancy presents as a

complex mass-like area representing hemorrhage and free fluid.

heterotopic pregnancy

concomitant intrauterine pregnancy and ectopic pregnancy.

limb-body wall complex

condition characterized by multiple complex fetal anomalies and a short umbilical cord

ectopic pregnancies diagnosed in early gestation allow for

conservative methods of treatment

Velamentous insertion

cord attachment to the edge of the placenta

Vasa previa

crossing of the cervix by the umbilical cord coexisting with a velamentous cord insertion or placental succenturiate.

retroperitoneal complex is

decidua basalis and portions of myometrium

the "empty amnion sign" means

definitive evidence of pregnancy failure

Cord prolapse

delivery of the cord before the fetus

an embryo measuring 5mm or greater should

demonstrate cardiac activity

repeated or serial levels of b-hcg are necessary to

detect and increase, decrease or leveling of the hormone.

a fetus with a long and narrow head is called

dolichocephalic

which phase of pregnancy provides the most accurate dating?

early embryo measurements

if the crown-rump length is more than 2 standard deviations below the mean for the expected gestational age,

early-onset intra uterine growth restriction may be suspected .

the perfect technique for measuring the fetal abdomen and head circumference is the

ellipse

sonographic appearance for an inevitable abortion

empty low-lying gestational sac and open cervix

the purpose of 2nd and 3rd trimester measurements of a fetus are

estimating fetal age and determining the size and development

Hyperthyroidism

excessive activity of thyroid

Bilobed placenta (succenturiate lobe)

extra placental lobe smaller than the placenta

what is a possible outcome of amnion rupture before the fetal age of 16 weeks?

extra-amniotic pregnancy/extra-amniotic coelom

Trophoblast

extraembryonic tissue that develops into the placenta

what is the pathway from the uterine cavity to the peritoneal cavity?

fallopian tubes

body stalk anomaly

fatal condition associated with multiple congenital anomalies and absence of the umbilical cord

cerebellar size is generally unaffected by

fetal growth disturbances and is independent of the shape of the cranium

Placenta membranacea

fetal membranes covered by chorionic villi due to failure of chorion differentiation into the chorion laeve and chorion frondosum

Aneurysm

focal dilatation of an artery

intrauterine contraceptive device (IUD)

form of birth control; small, plastic, or copper, usually T-shaped device, with a string attached to the end that is inserted into the uterus.

beam width artifact tends to make measurement points

fuzzy, therefore, cursors should be placed at the edge of the most definite echo observed, but should not include beam width artifact

interstitial pregnancy

gestation located in the intramyometrial segment of the fallopian tube.

cornual pregnancy

gestation located within a rudimentary uterine horn or one horn of a bicornuate or septated uterus.

Abdominal pregnancy

gestation located within the intra-peritoneal cavity, apart from tubal, ovarian, or intraligamentous sites.

abdominal pregnancy

gestation located within the intraperitoneal cavity apart from tubal, ovarian, or intralegamentous sites.

Intramural pregnancy

gestation located within the myometrium of the uterus

intramural

gestation located within the myometrium of the uterus

ovarian pregnancy

gestation located within the ovary

an intrauterine mass over 3.45 cm in largest diameter, a thin endometrium, and low resistance arterial Doppler flow is likely a form of

gestational trophoblastic disease.

Beta human chorionic gonadotropin (B-hCG)

glycoprotein hormone produced in pregnancy that is made by the developing embryo soon after conception and later by the placenta.

what laboratory value is useful when a smaller than expected gestational sac is seen with ultrasound?

hCG

enlarged ovaries are frequently seen during complete molar pregnancy as a result of elevated

hCG levels

Triploid, triploidy

having three copies of each chromosome.

Morison's pouch

hepatorenal recess; deep recess of the peritoneal cavity on the right side extending upward between the liver and the kidney; gravity-dependent portion f the peritoneal cavity when in the supine position,

cervical pregnancy frequently presents on ultrasound as a

hourglass-shaped uterus

when using a valid published fetal growth chart, it is important to know

how the measurements were generated, so that the examiner uses the same methodology that the chart was compiled on.

tubal ring sign

hyperechoic ring of trophoblastic tissue that surrounds an extrauterine gestational sac

Tubal ring sign

hyperechoic ring of trophoblastic tissue that surrounds an extrauterine gestational sac.

toxemia of pregnancy presents as pregnancy-induced

hypertension, proteinuria, edema, and headache and may progress to seizures (eclampsia).

ectopic pregnancy

implantation of a fertilized ovum in any area outside of the endometrial cavity

increased hCG lab levels and clinical signs and symptoms associated with complete molar pregnancies are more severe than

in partial moles

Respiratory insufficiency

inadequate absorption of oxygen and/or inadequate expulsion of carbon dioxide

the increase in C-section scar pregnancies is probably due to the

increase in number of the c-section deliveries

thinning of the myometrium behind the placenta may indicate the following

increta, accreta, and percreta. Except: adherence

pelvic inflammatory disease (PID)

infection of the female reproductive tract that results from microorganisms transmitted especially during sexual intercourse or by other means such as surgery, abortion, or parturition

Valsalva

inhalation and suspension of breath coupled with abdominal muscle contraction to increase abdominal pressure.

procedures that cause an injury to the myometrium, including curettage, hysteroscopy, myomectomy, metroplasty, and cesarean section can be the cause for

intramural pregnancy

Thrombosis

intraplacental area of hemorrhage and clot

heterotopic pregnancy means pregnancy

intrauterine and extrauterine, simultaneous

What is the most likely cord pathology demonstrated on the image?

large umbilical cord cyst pg 415

A complete hydatidiform mole usually results in:

large-for-dates uterus and vaginal bleeding

uterine vessels are most abundant along the

lateral uterine wall

early onset intrauterine growth restriction is defined as crown-rump length at

least 2 standard deviation below the mean for expected gestational age.

pregnancy failure is most likely to occur when the fetal heart rate is?

less than 110 beats per minute at 6.3 to 7 weeks

discriminatory cutoff

level of B-hCG at which a normal intrauterine pregnancy can be seen with sonography.

Synechia (Asherman syndrome)

linear, extra amniotic tissue that projects into the amniotic cavity with no restriction of fetal movement

Cotyledons

lobule or subdivision of maternal placenta containing fetal vessels, chorionic villi, and the intervillous space

molar pregnancy has the ability to develop into

locally invasive or metastatic gestational trophoblastic neoplasia, GTN aka choriocarcinoma

tall parents tend to have

long babies

placental blood flow should demonstrate as

low resistance

Placenta previa

low uterine implantation of the placenta resulting in total or partial covering of the cervix

which fibroid is most likely to obstruct vaginal delivery, requiring a cesarean delivery.

lower uterine segment

fetal weight by ultrasound is usually requested to rule out all of the following

macrosomia, IUGR, and possible low birth weight. Except: BPP

differences in fetal growth parameters can be caused by

maternal smoking, altitude and genetics

Occipito-frontal diameter (OFD)

measurement from the frontal to the occipital obtained at the same level as BPD.

normal pregnancies occur in all but where?

medial to the interstitial portion of the fallopian tubes.

Axial resolution

minimum distance between two bright echoes along the path of the ultrasound beam, which is half the spatial pulse length.

Lateral resolution

minimum distance between two bright echoes at right angels (perpendicular) to the ultrasound beam path directly related to the beam width and focal zone.

Wharton's jelly

mucous tissue surrounding the umbilical cord

the preferred measurement method for fetal growth is

multiple measurements in a cluster

the most accurate fetal measurement can be obtained from

multiple parameters

the intramural segment of the tube is surrounded by

myometrium, which allows for increased expansion compared to other tubal sections.

Does NOT indicate possible embryonic demise:

no cardiac activity with a < 5 mm embryo and a double bleb sign

determining sonographic dates for a fetus using a single parameter is

not desirable, especially in late pregnancy

marginal insertion (aka, battledore placenta)

occurs when the umbilical cord inserts at the placental margin instead of centrally

ectopic pregnancy can be caused by

oviduct surgical history

cervical pregnancy is rare and linked to all of the following, except

ovulation induction techniques

cervical incompetence is

painless cervical dilatation

what structures are seen in an accurate BPD measurement?

parietal, sphenoid, and petrous ridges

lateral resolution is

path of the beam

Fertilization

penetration of an oocyte by a sperm to form a diploid zygote.

Gastroschisis

periumbilical abdominal wall defect, typically to the right of normal cord insertion, that allows for free-floating bowel in the amniotic fluid.

Which of the following describes growth of the chorionic villi superficially into the myometrium?

placenta accreta

an abnormally thin placenta detected over most of the uterine cavity is

placenta membranacea

an overly distended maternal urinary bladder may cause misleading appearance of

placenta previa

Bilobed placenta

placenta where the lobes are nearly equal in size and the cord inserts into the chorionic bridge of tissue that connects the two lobes

Battledore placenta

placenta with umbilical cord inserted into the border

Intervillous spaces (sinus)

placental spaces that communicate with maternal vessels

the role of sonography in early threatened pregnancy is not to alter the outcome, but to

predict which will continue to term.

pregnancy of unknown location (PUL)

pregnancy in which no signs of an intrauterine pregnancy or ectopic pregnancy are seen by sonography

Pregnancy of unknown location (PUL)

pregnancy in which no signs of an intrauterine pregnancy or ectopic pregnancy are seen by sonography.

Toxemia of pregnancy

pregnancy induced hypertension, proteinuria, edema and headache (preeclampsia), which may progress to the development of seizures (eclampsia)

cervical pregnancy

pregnancy located within the endocervical canal

Abruptio placentae

premature separation of the placenta from the uterus

Which of the following identifies the sonographic finding in the uterus which is made up of bleeding from the decidualized endometrium?

pseudosac

Cephalic index (CI)

ratio of the PBD to the OFD

True knot

result of the fetus actually passing through a loop or loops of umbilical cord creating one or more knots in the cord

a yolk sac with healthiest characteristics is

round in shape

a positive pregnancy test without visualization of uterine contents, adnexal mass, and free fluid indicate

ruptured ectopic pregnancy

hypovolemic shock

shock due to a decrease in blood volume.

platycephaly is

shortening of the vertical dimension of the skull and widening of both diameters of the transverse plane.

in vitro fertilization (IVF)

sperm is placed with an unfertilized egg in a petri dish to achieve fertilization; the embryo is then transferred into the uterus to begin a pregnancy or cryopreserved for future use.

Incomplete abortion

spontaneous abortion in which some products of conception remain in the uterus.

Cerclage

stitch placed into the incompetent cervix to prevent opening

if the umbilical/portal junction is not visualized while attempting an AC measurement, use the level of the fetal

stomach

the risk of spontaneous mis carriage, preeclampsia, placental abnormalities, or preterm delivery is increased by crescent-shaped sonolucent fluid between the gestational sac and the uterine wall is called:

subchorionic hematoma

Hemodynamically unstable patients with a known ectopic pregnancy require

surgical management, the most successful being laparoscopy.

Placentomegaly

term that refers to a thickened placenta

Mickey Mouse sign

term used to describe the cross-section of the three-vessel umbilical cord or the portal triad (portal vein, hepatic artery, common bile duct)

the area most likely to collect fluid in the right abdomen, between liver and kidney is called

the Morrison's pouch

MFP (multiple fetal parameter) is

the average gestational age determined by 4 common measurements of the fetus

short and frequent pulses yield

the greatest axial resolution

a hemorrhage due to ectopic rupture of the oviduct is most severe in

the interstitial portion

the more measurements obtained and averaged during a fetal ultrasound

the more accurate the fetal age estimate.

a sonogram is ordered to date a pregnancy if

the patient is unsure of LMP and if clinical exam of the uterus does not agree with the patient's reported LMP

ultrasund demonstrates and incomplete abortion as a

thickened endometrium or hyperechoic tissue within the uterus

Which fetal leg bone is medial and larger?

tibia

Placental infarction

tissue death resulting form circulatory obstruction

the recommended technique to obtain an accurate AC is

to first locate the long axis of the fetal spine

if the b-hcg level is above the discriminatory cutoff and no IUP is visualized, through

transabdominal, transvaginal sonography should be performed

Which of the following is a cause for abruption placenta?

trauma

double decidual sac sign (DDS)

two concentric hyperechoic rings (representing the echogenic base of the endometrium and the decidua capsularis/chorion levae) surrounding the anechoic gestational sac in a normal intrauterine pregnancy

double decidual sac sign

two concentric hyperechoic rings, representing the echogenic base of the endometrium and the decidua capsularis/chorion leave, surrounding the anechoic gestational sac in a normal intrauterine pregnancy.

Which term describes a method of assessing the degree of umbilical cord coiling?

umbilical coiling index

A correct AC measurement demonstrates the

umbilical vein junction with the portal vein perpendicular to the spine

a blighted ovum is also called an

unembrionic pregnancy.

an HC measurement should be obtained

using outer edge of the calvarium at the level of BPD

Braxton-Hicks

uterine contractions that do not lead to labor

uterine size estimation by physical examination to determine pregnancy age may be INACCURATE due to all of the following:

uterine fibroids, maternal obesity, and surgical scars. Except: parity

Threatened abortion, threatened miscarriage

vaginal bleeding in early pregnancy of less than 20 weeks; may be accompanied by pain or cramping.

ectopic pregnancy symptoms usually present as

vaginal bleeding, pelvic pain, and palpable adnexal mass.

What occurs when the intramembranous vessels course across the internal cervical os?

vasa previa

Breus' mole

very rare condition where there is massive subchorionic thrombosis of the placenta secondary to extreme venous obstruction

Sliding sac sign

when gentle pressure from the transducer moves the gestational sac

sliding sac sign

when gentle pressure from the transducer moves the gestational sac

Vernix caseosum

white, cheesecake coating of fetal skin

Which of the following is the blastocyst layer that eventually develops into the embryonic portion of the placenta?

Trophoblast

Which of the following is the structure that produces the embryo's first blood cells?

Umbilical vesicle


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