OB GYN CTL 1st Trimester Anatomy & Pathology (12%)

The neural tube normally closes by week __________

6

During fetal development, what describes the fetal component of the placenta?

chorion frondosum

The yolk sac can first be visualized with transvaginal sonography at what gestational age?

5.5 weeks

The double sac sign seen in early pregnancy refers to:

fluid filled gestational sac and fluid filled uterine cavity are both visible with transvaginal sonography

The "twin peak" sign is associated with what type of pregnancy?

diamniotic/dichorionic

Using transvaginal ultrasound, the minimum mean sac diameter that should always demonstrate an embryo is:

16mm

Preeclampsia in the first trimester of pregnancy is not commonly associated with:

molar pregnancy

Which of the following is/are a sign of Spina Bifida in a 13 week fetus?

obliterated cisterna magna and intracranial translucency

A patient who has a history of taking fertility medication presents for a fetal viability scan. The fetus ia approximately 6 weeks old by LMP. Serum levels were performed by her doctor 5 days ago and bhCG levels were 4000 units/ml. Today the level of bhCG is 4200 units/ml. What is the most likely finding on the transvaginal US exam?

blighted ovum

The embryo is most sensitive to teratogenic effects between __________ and __________ weeks gestation

3 and 8 weeks

A patient is admitted to the hospital with a pelvic pain, no bleeding and vomiting. An LMP of 6 weeks ago and the pregnancy test that was performed was positive. Serial hCG levels are assessed 36 hours apart. The first reading was 1500/ml and the second reading was 2000/ml. Ultrasound is ordered to assess the pregnancy. What should you expect to find on the exam.

ectopic pregnancy

A compressed or absent intracranial translucency in a 13 week fetus is an indicator for:

spina bifida

The gestational sac with __________ are the first signs of an intrauterine pregnancy seen with ultrasound

decimal reaction of the endometrium

Which of the following is associated with an inevitable abortion, but is not present with a threatened abortion

dilated cervix

Which of the following describes the function of the chorionic villi?

to provide nourishment to the fetal blood

Which biometric measurement is not used to estimate fetal age in a detailed evaluation of a 13 week fetus?

femur length

Which of the following is the recommended method to document fetal number in an early pregnancy?

count the number of visible embryos

Implantation of the fertilized egg occurs day _____-_____ of the pregnancy

20-23

When the cephalic end of the neural tube fails to close, __________ occurs. When the distal end of the neural tube fails to close, __________ occurs

anencephaly

spina bifida

The first trimester of pregnancy is defined as weeks __________ through __________ gestational age

1

13

Which of the following early embryologic structures produce progesterone?

trophoblastic cells

In an early intrauterine pregnancy, the amniotic sac and yolk sac are collectively called:

the double bleb sign

Which of the following is most suggestive of an inevitable abortion?

cervical dilatation over 3cm

When evaluating the ductus venosus with spectral doppler:

color doppler is used to demonstrate the umbilical vein, ductus venosus and heart in the same image

A fetal heart rate __________ indicates a significant risk for demise in the first trimester

less than 80 bpm

Which of the following is NOT commonly associated with anencephaly?

oligohydramnios

An ectopic pregnancy will almost always be seen on the __________

same side as the corpus luteal cyst

Using transvaginal sonography, the yolk sac can be identified as early as week __________ of the pregnancy

5

A patient presents for a fetal viability scan with an LMP 10 weeks ago. She has been experiencing light vaginal spotting for then last week. The transvaginal exam demonstrates a 2cm crescent shaped hypoechoic area between the chorion and right uterine wall. These findings are most suggestive of:

subchorionic hemorrhage

In the 1st trimester, the 4th ventricle is also called:

intracranial translucency

All of the following are signs of embryonic demise, except:

double bleb sign

A patient presents for a pelvic ultrasound due to pain and bloating. Her LMP was 5 weeks ago and bcHG levels are at 10unit/ml. A mild amount of anechoic fluid is noted in the posterior cup de sac. All of the following are a potential cause for the fluid accumulation, except:

ectopic

Crown rump length (CRL) measures 7mm. What is the estimated gestational age of the pregnancy?

7 weeks

On transvaginal sonography, cardiac activity must be identified in an embryo with a CRL of __________ or greater to be considered a viable IUP

7mm

An asymptomatic patient presents for a viability scan. Using the transvaginal approach, a 15mm fetal pole is identified without cardiac activity. The yolk sac is present within the gestational sac. Which oof the following best describes these finding?

embryonic demise

The mean sac diameter in a normal IUP will demonstrate __________ increase in size per day up until the 10th week of gestation

1mm

Which of the following is a characteristic of an incomplete abortion?

slower than expected decrease in hCG levels

When evaluating a first trimester fetus, the reported crown rump length should be:

the average of at least three measurements

When is PW Doppler appropriate to evaluate the first trimester fetus?

when aneuploidy is suspected

A patient presents with an LMP of 7 weeks 4 days. The script states the fundal height is large for gestational age and acute onset of systemic HTN. These clinical findings are most suggestive of:

molar pregnancy

Which of the following is a sonographic sign of an abnormal 8 week intrauterine pregnancy?

gestational sac located in the lower uterine segment

If fertilization occurs, __________ will stop the regression of corpus luteal cyst so that it can produce progesterone to stimulate the decimal reaction

bhCG

The number of yolk sacs can be used to determine:

the amnionicity of the multifetal pregnancy

When evaluating the fetal heart in a 13 week 3 day fetus, the 4 chamber view with and without color and the 3 vessel trachea view with color are part of the standard AIUM protocol. What other image must be recorded to demonstrate proper cardiac position and axis?

fetal stomach

The chorionicity and amnionicity of a twin pregnancy is determined by:

timing of the cell division in the zygote

All of the following are layers of the endometrium that form with pregnancy, except:

decidua accreta

The most common location of an ectopic pregnancy is:

ampulla

Which of the following types of twin gestation will have the highest risk for conjoined twins?

monochorionic/monoamniotic

What abnormality occurs when two sperm fertile the same egg?

triploidy

A normal ductus venosus waveform in the first trimester fetus demonstrates :

a biphasic pattern with antegrade A-wave

What is the most common cause of demise in the first trimester?

chromosomal abnormalities

Mild tricuspid regurgitation in a first trimester fetus is suggestive of:

aneuploidy

The embryo of a normal pregnancy will increase in size approximately __________

1mm every day

Which of the following statements is correct regarding multifetal pregnancy?

easiest to determine amnionicity/chorionicity in the first trimester, around 8 weeks gestation

Which of the following adnexal masses is a sign of a normal intrauterine pregnancy?

corpus lute cyst

Which of the following is responsible for the symptoms of early pregnancy, such as nausea and vomiting?

progesterone

The AIUM defines a late trimester ultrasound evaluation as an exam performed on a fetus that is between:

12 and 13 weeks 6 days of age

Average normal heart rate in an early first trimester pregnancy is __________

100-115bpm

The earliest gestational age the gestational sac can be seen transvaginally is?

4 weeks

The yolk sac is considered normal in size when the inner diameter is less than __________

6mm

Which of the following demonstrates the lowest risk of embryonic demise?

TV ultrasound identifies a gestational sac with MSD 12mm and 5mm yolk sac but no embryo

While scanning an asymptomatic patient with a 10wk gestation, you identify a complex cyst in the right ovary. This finding is most suggestive of:

corpus luteal cyst

At what gestational age does the CRL become less accurate for fetal dating?

at the 12th week

Diabetes mellitus is associated with:

increases risk of embryonic demise and miscarriage in the first trimester

The embryo and yolk sac can be seen with TV ultrasound as early as:

5.5 weeks

Which of the following types of twin gestation will have the thickest membrane between the fetuses?

dichorionic/diamniotic

Sn IRP bhCG level of __________ units/ml should definitely correspond with visualization of an IUP by transvaginal ultrasound

2000

Which of the following is a possible maternal complication of diamniotic twins?

anemia

The __________ forms the outer layer of the placenta that is in contact with the endometrium

chorion

What type of holoprosencephaly can be identified in a 13 weeks fetus?

alobar

__________ refers to bhCG levels in blood that correspond with the first possible sonographic visualization of the gestational sac in a normal IUP. __________ refers to the bhCG levels in blood that must correspond with the sonographic visualization of the gestational sac in a normal IUP

threshold

discriminatory zone

Which of the following correctly describes the nuchal translucency measurement?

multiple measurements should be obtained and the largest one that follows the measurement criteria correctly is reported

On transvaginal ultrasound, the minimum mean sac diameter that should always demonstrate a yolk sac in a normal IUP is:

8mm

A 26yr old patient presents with a positive pregnancy test and an approximate age of 7 weeks 3 days fro. her LMP. Beta hCG levels are significantly higher than a 7 week gestation. The exam shows a large heterogeneous solid mass measuring

6 x 4 x 3 cm within the endometrial cavity. The uterus measures 10 x 6 x 5 cm. What is the most likely explanation for the sonographic findings described?

hydatidiform mole

Which of the following signs indicates an abnormal early pregnancy?

cullen sign

Fetal cardiac activity can first visualized with transvaginal sonography at approximately what gestational age?

6 weeks

During fetal development, which of the following describes the maternal component of the placenta?

decidua basalis

What is the minimum international reference preparation value for bhCG that indicates a gestational sac should definitely be visualized by transabdominal ultrasound?

4000units/ml

Which of the following statements regarding twins is true?

most monozygous pregnancies are diamniotic

How are the long bones of the extremities evaluated in a 13 week fetus with suspected cardiac defects?

document 3 long bones are present in each extremity

What cardiac view is used to document proper fetal heart position on a first trimester exam?

4 chamber view

Conception occurs approximately:

2 weeks after the last menstruation

Which of the following is a sign of impending fetal demise?

irregular gestational sac shape

To obtain a PW Doppler evaluation of the tricuspid valve:

place the cursor line parallel to the interventricular septum

One yolk sac with two embryos indicates:

monoamniotic twins

The discriminatory bhCG level refers to:

bhCG levels in blood that MUST correspond with the sonographic visualization of the gestational sac

With transabdominal ultrasound, a blighted ovum is diagnosed with a mean gestational sac diameter greater than __________ without a fetal pole present

25mm

A patient is admitted to the hospital with a pelvic pain, no bleeding and vomiting. An LMP of 6 weeks ago and the pregnancy test that was performed was positive. Serial hCG levels are assessed 36 hours apart. The first reading was 1500/ml and the second reading was 4500/ml. Ultrasound is ordered to assess the pregnancy. What should you expect to find on the exam?

molar pregnancy or multiple pregnancy

A 25yr old patient presents for a first trimester scan with uterine size consistent with a 12wk fetus but the LMP indicates a 7 week pregnancy. You identify a mass of mottled tissue with cystic components and internal blood flow that occupies the fundus of the uterine cavity. There is also a gestational sac with a 4mm embryo identified in the inferior portion of the endometrial canal. Which of the following best describes these findings?

partial molar pregnancy

Which of the following carries the lowest risk of spontaneous abortion?

gestational sac implanted in the endometrial cavity near the uterine cornea

Which of the following describes the sonographic appearance of a normal nasal bone in a 1st trimester fetus?

two parallel lines, resembles an equals sign (=)

What sonographic "sign" refers to the overlapping of the cranial sutures with fetal demise?

spalding sign

Megacystitis in a first trimester is diagnosed when the bladder length is greater than or equal to:

7mm

A patient with a history of an 8 week pregnancy presents for an ultrasound due to pelvic pain and moderate bleeding for the last 4 days. What is the most likely finding on todays exam?

spontaneous abortion

An asymptomatic patient presents for a viability scan in the first trimester. The ultrasound exam demonstrates a fetal pole that measures at 7 weeks 2 days. A 7mm yolk sac is identified. The fetal HR is evaluated by m-mode and is estimated at 79bpm. There is no evidence of subchorionic hemorrhage. Which of the following statements is true?

The yolk sac is abnormally enlarged and the fetal heart rate is lower than normal

The chorionic villi and membrane are formed from the:

trophoblastic cells

The most common place for normal egg fertilization to occur is within which of the following fallopian tube segments?

ampulla

The most commonly identified predictor of poor outcome in a first trimester ultrasound is:

abnormally large yolk sac

Regarding twin pregnancy, if division of the zygote is not complete by day 13 of the gestation it will result in:

conjoined twins

What are the two most common neural tube defects?

anencephaly and spina bifida