Ch. 50 Abnormal 1st Trimester Pregnancy Flashcards
The dominant structure seen in the embryonic cranium during the 1st trimester is the
choroid plexus
_____ is a congenital malformation of the brain and face caused by failure of the telecephalon to completely develop
holoprosencephaly
Ossification of the cranium is completed in the 1st trimester
false
If an embryonic cranial abnormality is suspected in the 1st trimester
the fetus is rescanned after 14 weeks
An echogenic mass in the base of the umbilical cord joining the embryonic abdomen at 10 weeks may be
Normal herniation of the gut outside the abdominal wall or omphalocele
Omphaloceles containing only bowel are easily diagnosed in the 1st trimester
false
Omphaloceles are associated with chromosomal anomalies
true
______ is one of the most common congenital defects seen in the 1st trimester
cystic hygroma
Can hydrocephalus be diagnosed in the 1st trimester of pregnancy
no, 14 weeks
Cystic hygroma is caused by abnormal development of the
lymphatic system
Cystic hygroma is associated with ______, especially when diagnosed in the 1st trimester
chromosomal abnormalities
_______ is the most common chromosomal abnormality that occurs in fetuses who are diagnosed with cystic hygroma in the 2nd or 3rd trimesters
turners syndrome
A cystic structure arising from the posterior fetal neck and upper thorax seen in the 1st trimester is most likely a
cystic hygroma
A nuchal translucency measurement of more than _____mm is always abnormal
2.5mm
The upper limit of normal for nuchal translucency _____ with increasing gestational age up to 14 weeks
increases
Nuchal translucency measurements should be performed with _____ imaging
TA or TV
The magnification of the image is not important when measuring nuchal translucency
false
_____ of fetuses with trisomy 21 will have abnormal nuchal translucency
70%
______ are associated with increased nuchal translucency, even if the karotype is normal
cardiac defects
Increased nuchal translucency is associated with which of the following
trisomy 13,18,21 and triploidy
______ is a gel like substance that surrounds and cushions the vessels of the umbilical cord
whartons jelly
If an umbilical cord cyst is seen in the late 2nd trimester, genetic analysis may be indicated
true
A common cause of 1st trimester vaginal bleeding is
ectopic pregnancy and retroplacental hematoma
_____ is caused by a separation of part of the placenta from the uterine wall
retroplacental hematoma
The larger the retroplacental hematoma is, the less likely it is that the pregnancy will be lost
false
The _____ is the most common ovarian mass seen in the 1st trimester of pregnancy
corpus luteum cyst
Corpus luteum cysts are usually not seen after _____ weeks
18
Ovarian cysts that persists into the 2nd or 3rd trimesters are at higher risk for
torsion
Why is it important to document the location of the placenta in relation to uterine fibroids
because they reduce the source of blood supply for the placenta if they are located beneath it
Fibroids frequently grow during pregnancy due to
estrogen stimulation
_____ may be mistaken for a fibroid
focal uterine contractions
One of the most important diagnoses made by sonography is
ectopic pregnancy
Why has the incidence of ectopic pregnancy increased in recent years
increase risk with PID, IUD, infertile patients and endometriosis
The most common symptom of ectopic pregnancy is
acute pelvic pain
The bleeding associated with ectopic pregnancy is caused by
invasion of the fallopian tube by trophoblastic tissue
Sonographically, the absolute positive diagnosis of ectopic pregnancy is made by
identification of a gestational sac outside the uterus
The most common site of ectopic pregnancy is
fallopian tube
Why is it important for the sonographer to know which preparation or standard is used by the lab for quantitative HCG levels
because IRP numbers are twice 2IS at the same time of pregnancy
A fluid collection often seen in the uterine cavity in cases of ectopic pregnancy is called a
pseudogestational sac
How does the sonographer distinguish pseudogestational sac from intrauterine pregnancy
no fetal pole or yolk sac, filled with low level echoes, no trophblastic flow
Doppler flow around a gestational sac is
low resistance and high velocity
Flow pattern with low resistance and high velocity is referred to as
trophoblastic flow
Mandy came to the emergency room complaining of severe pelvic pain. Bloodwork revealed a positive pregnancy test. Transvaginal sonography demonstrated an empty uterus, a right adnexal mass, and free fluid in the pelvis with a sand-like texture. No definite gestational sac was seen. What is most likely the diagnosis? What does the right adnexal mass represent? Why does the free fluid have echoes?
ectopic pregnancy, hematoma from ruptured tube, blood
Which imaging method is used when imaging ectopic pregnancy
TA and TV
Define heterotopic pregnancy
coexisting and intrauterine pregnancies
`What treatments increase the risk of heterotopic pregnancy
in patients undergoing ovulation induction of IVF
______ is the most dangerous type of ectopic pregnancy
cornual and interstitual
Why is interstitial ectopic pregnancy so dangerous
tremendous blood supply and potential for hemorrhage upon rupture
Define cervical pregnancy
gestational sac implants in cervix
If the fetal heart rate in the 1st trimester is less than 90 bpm, the prognosis is poor
true
If the MSD is _____ less than the CRL, oligohydramnios may be suspected
4mm
Embryos with 1st trimester oligohydramnios always die
true
Diagnosis of _____ requires serial sonograms
embryonic growth retardation
Describe the sonographic appearance of complete abortion
reveals empty uterus with normal endo with no adnexal mass or free fluid
Describe the sonographic appearance of incomplete abortion
thickened or irregular endometrial echos, may see fluid in endo, no heart tones
What is another term for imcomplete abortion
missed abortion
Define anembryonic pregnancy
blighted ovum, gest sac is present but no embryo develops
Molar pregnancy is easily diagnosed in the 1st trimester
false
The snowstorm or bunches of grapes appearance of molar pregnancy appears to be specific to the ____ trimester
2nd
With molar pregnancy, HCG levels are ____ than expected
higher
Why are serial HCG levels done after evacuation of a molar pregnancy
to ensure tropho tissue has been removed
_____ refers to a group of tumors that arise from the chorionic villi of the placenta
gestational trophoblastic disease
Abnormal proliferation of the trophoblast leads to
molar pregnancy
_____ is the most common form of trophoblastic disease and is benign
hyatidiform mole
Increased maternal age leads to a ____ risk for molar pregnancy
increased
Previous history of molar pregnancy leads to a _____ risk for molar pregnancy
increased
______ has only trophoblastic material and no fetal parts
complete molar pregnancy
_____ occurs when a sperm fertilizes an ovum that contains no chromosomes
complete molar pregnancy
______ are locally invasive but do not metastasize
invasive molar pregnancies
______ is both locally invasive and will develop distant mets
choriocarcinoma
What characteristics help the sonographer distinguish between hydropic degeneration of the placenta and molar pregnancy
HCG levels and presence of normal fetus
