1st Trimester Complications Flashcards
1
Q
Based on what hCG values should a pregnancy be seen using transvaginal US?
A
800 to 1000 IU/L based on 2IS (second international standard)
1000 to 2000 IU/L based on first IRP (first international reference preparation)
2
Q
Normal intrauterine pregnancy under 7 weeks demonstrates __ of quantitative maternal serum hCG levels every 3.5 days; or increase __% in hCG levels within __hours.
A
Normal intrauterine pregnancy under 7 weeks demonstrates doubling of quantitative maternal serum hCG levels every 3.5 days; or increase 66% in hCG levels within 48 hours.
3
Q
When do hCG levels plateau and subsequently decline while gestation continues to grow?
A
9-10 weeks
4
Q
With what pathology do hCG levels plateau later and fall much more slowly?
A
trisomy 21
5
Q
How can hCG be used as a screening marker for trisomy 21?
What subunit is most sensitive for this pathology?
A
hCG will be increased during 1st and 2nd trimesters; but cannot be used by itself to diagnose.
beta subunit
6
Q
Normally, pregnancy-associated plasma protein (PAPP-A) does what with advancing gestation?
A
increases
7
Q
What does PAPP-A do with trisomy 21?
A
is initially lower than normal, but decreases with advancing gestation
8
Q
At what gestational age is PAPP-A the strongest biochemical marker for trisomy 21?
A
9-11 weeks
9
Q
What is the most emergent diagnoses made with sonography?
A
ectopic pregnancy
10
Q
What percentage of ectopic pregnancies take place in the fallopian tubes? In the ampula?
A
95-99% in fallopian tubes
70% in ampula
11
Q
What are the risk factors for ectopic pregnancy?
A
rise in incidence of pelvic infections, use of IUDs (having IUD while pregnant), infertility treatments, history of ectopic pregnancies, fallopian tube surgeries, disruption of normal tubal pathways (scarring, endometriosis)
12
Q
What is the most important risk factor for ectopic pregnancy?
A
history of ectopic pregnancy
13
Q
Clinical Symptoms for ectopic pregnancy:
A
vaginal bleeding, positive pregnancy test, back pain, shock symptoms, abnormal hCG levels
14
Q
Other than in fallopian tubes, where can ectopic pregnancies take place?
A
ovary, broad ligament, peritoneum, cervix and cornua
15
Q
Sonographic findings for ectopic pregnancy:
A
pseudogestational sac with homogeneous level echoes, empty uterus, presence of adnexal mass, echogenic free fluid in POD
16
Q
What is a pseudogestational sac?
A
does not contain either living embryo or yolk sac; centrally located within endometrial cavity (vs burrowed sac that is eccentrically located), has homogeneous echoes
17
Q
Extrauterine gestational sacs often demonstrate:
A
thickened echogenic ring (trophoblastic tissue)
18
Q
Risk of ectopic pregnancy can be greater than __% when intrauterine gestation absent and there is corresponding adnexal mass
A
90%
19
Q
What is correlated with an increased risk of ectopic?
A
moderate to large amounts of free intraperitoneal fluid and associated adnexal mass
20
Q
What is the most life-threatening of all ectopic gestations?
A
interstitial pregnancy (at segment of fallopian tube that enters uterus)
21
Q
What makes interstitial ectopic such a dangerous location?
A
involves parauterine and myometrial vasculature, creating life threatening hemorrhage when rupture occurs
22
Q
What type of ectopic has an increased risk of complete hysterectomy? Why?
A
cervical pregnancy
because of uncontrollable bleeding caused by increased vascularity of cervix
23
Q
Name the different location of ectopic pregnancies.
A
ovarian, peritoneal, tubal, isthmic, and cervical
24
Q
What is the most common presentation for complication?
A
first trimester bleeding
25
Why would bleeding occur in the first trimester?
normal implantation, ectopic pregnancy, spontaneous abortion, subchronic hemorrhage
26
Pregnancy is unlikely to progress if bleeding is accompanied by...
severe pain, uterine contractions, dilated cervix
27
___% of pregnancies result in 1st trimester spontaneous abortion. When does this occur?
15-20%
| happens in first 6-8 weeks
28
List the five types of abortions.
complete, incomplete, threatend, missed, and inevitable
29
Describe each type of abortion: complete, incomplete, threatend, missed, and inevitable
complete: expulsion of all products of conception(POC)
incomplete: partial expulsion of POC
inevitable: no expulsion of POC, open cervix, contractions, no progression
threatened: bleeding, no expulsion of POC, cervix closed, pregnancy may progress
missed: no expulsion of POC, complete retention of POC
30
What is an abortus?
fetus exposed prior to 20 weeks or less than 500g
31
Sonographic findings of incomplete spontaneous abortion:
ranges from intact gestational sac with nonviable embryo to collapsed gestational sac grossly misshapen
32
Sonographic signs for retained products:
thickened endometrium ( >8mm), increased vascularization of endometrial complex (color doppler strongly predictive)
33
What are signs of a spontaneous abortion?
presence of visible embryonic parts, gestational sac, embryonic disc, obvious evidence of retained products of conception, no heart activity
34
What is the most common occurrence of bleeding in first trimester?
subchorionic hemorrhage
35
How does a subchorionic hemorrhage occur?
the low pressure bleed results from the process of implantation of fertilized ovum into endometrial cavity and myometrial wall
36
Where is a subchorionic hemorrhage found?
between myometrium and margins of gestational sac (between chorion and wall of uterine cavity)?
37
Clinical Symptoms for subchorionic hemorrhage:
bleedings, spotting or uterine cramping; if hemorrhage becomes large enough, can lead to spontaneous abortion
38
Sonographic finding for subchorionic hemorrhage:
early bleed: slightly echogenic as RBC actively fill area of hemorrhage
with time, becomes more anechoic; avascular
39
If a patient has a positive pregnancy test, but a normal uterus/endometrium with no gestational sac, what should be suspected?
very early intrauterine pregnancy (between 3 and 5 weeks), nondeveloping pregnancy, ectopic pregnancy
40
Sonographic findings for absent intrauterine sac:
empty uterus with no evidence for endometrial fluid collection, absence of adnexal masses or ff, positive beta-hCG level
41
How fast does a normal intrauterine sac grow? How fast does a normal embryo grow?
1mm per day in the first trimester
42
At what size should the gestational sac be to see the yolk sac transvaginally?
8mm in size
43
When should the embryo be visualized?
when the MSD is greater than 16 mm
44
Differentials of gestational sac without embryo or yolk sac:
normal early intrauterine pregnancy less than 5 weeks, abnormal intrauterine pregnancy, pseudogestational sac in patient with ectopic
45
Criteria for abnormal sac:
lack of appropriate growth indicates abnormal sac; if embryo not detected at 6.4 weeks, diagnosis of spontaneous pregnancy loss can be made
46
What is a blighted ovum/anembryonic pregnancy?
gestational sac in which embryo fails to develop or stops developing at such early stage that it is imperceptible by US
47
What happens to the gestational sac with a blighted ovum?
continues to grow
48
Sonographic findings for blighted ovum:
large, empty gestational sac; no yolk sac, amnion, or embryo; MSD increases by 0.7mm/day (normal=1.13mm/day)
49
Findings in a gestational sac associated with abnormal intrauterine pregnancies include:
absence of cardiac motion in embryo 5mm or larger, absence of cardiac motion after 6.5 menstrual weeks, large yolk sac or amnion without visible embryo, calcified yolk sac;
gestational sac greater than 18mm and lacking viable embryo, gestational sac greater than 8mm and lacking visible yolk sac, irregular/misshapen sac, sac in the position of cornula, low or hourglassing through cervical os;
irregular trophoblastic reaction, absent double decidual sac finding, thin trophoblastic reaction (less than 2mm), intratrophoblastic venous flow, gestational sac growth of less than .6mm/day, absent embryonic growth, discrepancy in sac size with hCG level
50
What is gestational trophoblastic disease?
proliferative disease of trophoblast after abnormal conception
51
benign form of gestational trophoblastic disease include:
hydatidiform mole (partial, complete, coexistent)
52
malignant form of gestational trophoblastic disease include:
invasive mole or choriocarcinoma
53
Clinically, what does gestational trophoblastic disease look like?
vaginal bleeding, beta hCG dramatically elevated (>100,000), severe nausea/vomiting (hyperemesis gravidarum), low AFP levels
54
What is a complete molar pregnancy?
occurs when egg without nucleus is fertilized by one normal sperm
55
Sonographic findings for complete mole:
snowstorm appearance: moderately echogenic soft tissue mass filling uterine cavity marked with small cystic spaces representing hydropic chorionic villi (grape-like)
uterus larger than dates, heterogeneous complex pattern, bilateral adnexal fullness, ovarian enlargement (theca lutein cysts)
56
Sonographic findings for partial mole:
placental tissue grossly enlarged and engorged with cystic spaces, embryo/embryonic tissue may be identified
57
Appearance of first trimester molar pregnancy may stimulate:
missed abortion, incomplete abortion, blighted ovum, hydropic degeneration of placenta associated with missed abortion
58
Malignant forms of trophoblastic disease include:
invasive mole and choriocarcinoma
59
When does invasive hydatidiform mole occur?
when hydropic villi of partial/complete mole invades uterine myometrium and at further penetrate uterine wall
60
Clinically, invasive hydatidiform mole look like...
continued heavy bleeding, severe nausea/vomiting, very elevated hCG levels
61
Sonographically, invasive hydatidiform appears....
enlarged uterus with multiple focal areas of grape-like structures throughout
62
Can choriocarcinoma metastasize?
fast growing, commonly metastasizes to lungs, liver, brain
63
Choriocarcinoma clinically appears:
vaginal bleeding, dyspnea, abdominal pain, neurologic symptoms
64
What is the first conclusive sonographic sign of viability?
identifying IUP with/without cardiac activity
65
When does the heart tube form?
between 3.5 and 5 weeks of conception
66
What embryonic cardiac rates have a poor prognostic finding?
less than 90 bpm
| and greater than 170 bpm (may lead to heart failure and fetal hydrops)
67
What is the expected growth of the yolk sac?
.3mm/day
68
What is the normal maximum diameter for the yolk sac?
5.5mm between 5 and 10 weeks gestation
69
A yolk sac of what size has an increased risk for spontaneous pregnancy loss?
5.6mm or greater
70
What is the double bleb sign?
simultaneous side by side appearance of amnion and yolk sac
71
The mean amniotic sac diameter should be equal to...
the CRL
72
Where is the embryonic disc located?
between the amnion and yolk sac
73
When is the amnion best seen?
transvaginally between the fifth and seventh weeks of gestation
74
When is the nuchal translucency the thickest?
at 11 to 14 weeks gestation
75
An increased nuchal translucency can be found in...
trisomy 13,18,21, or fetuses with cardiac defects and other genetic syndromes
76
What is the criteria for nuchal translucency measurements?
between 11 weeks and 13 weeks 6 days old, CRL must be between 45mm and 84mm, sonographer must obtain optimal mid-sagittal view, and embryo must be away from amniotic membrane with head in neutral position, no hyperextension or flexion
77
What is one of the most common abnormalities seen sonographically in the first trimester?
cystic hygroma
78
What specific chromosomal abnormalities does cystic hygroma associate with?
trisomies 13,18,21
79
What is the most important marker in the first trimester for Turner's Syndrome?
cystic hygroma
80
Where does cystic hygroma appear?
posterior aspect of fetal neck and upper thorax
81
Any posterior neck thickness greater than __, with or without septations, should be followed
3mm
82
When can the embryonic head sonographically be seen?
7 weeks
83
When does ossification of the cranium begin?
after 9 weeks
84
What are the dominant structures seen within the embryonic cranium in the first trimester?
choroid plexus, which fills lateral ventricles that in turn fill cranial vault
85
What does the brain look like at 7-8 weeks gestation?
cystic
86
What is visualized in the brain at 12-13 weeks gestation?
falx cerebral, lateral ventricles with choroid plexus
87
What is acrania?
partial or complete absence of cranium
88
What is acrania a predecessor of?
anencephaly
89
When acrania occurs, what happens to the fetal head?
has abnormally shaped head, referred to as "Mickey Mouse" head
90
What is anencephaly?
congenital absence of brain and cranial vault
91
What does anencephaly look like?
cerebral hemispheres either missing or reduced to small sizes; frog appearance (bulging eyes with nothing above)
92
What is cephalocele?
midline cranial defect in which there is herniation of the brain and meninges
93
What regions of the head does cephalocele involve?
occipital, frontal, parietal, orbital, nasal, or nasopharyngeal
94
In what areas of the world is cephalocele more common?
in the western hemisphere, occipital defects are more common; in eastern hemisphere, frontal defects are more common
95
What is iniencephaly?
rare, lethal anomaly of cranial development whose primary abnormalities include: defect in involving foramen magnum, retroflexion of spine where fetus looks upward with occipital cranium directed toward lumbar spine, open spinal defects
96
What is ventriculomegaly and when is it seen?
dilation of vetricular system without enlargement of cranium; after 11 weeks
97
What does ventriculomegaly look like sonographically?
choroid plexus shown to be dangling in dilated dependent lateral ventricle, compression and thinning of choroid plexus
98
What is holoprosencephaly?
malformation sequence that results from failure of prosencephalon to differentiate into cerebral hemispheres and lateral ventricles between 4th and 8th gestational weeks
99
What facial defects are associated with holoprosencephaly?
one eye, smaller distance between eyes, protruding trunk like tissue on face
100
What three types is holoprosencephaly divided into?
alobar, semilobar, and lobar
101
What type of holoprosencephaly is the most serious?
alobar consisting of single ventricle, small cerebrum, fused thalami, agenesis of corpus callosum, falx cerebri
102
When does spina bifida occur?
when there is a failure of neural tube to close after 6 weeks gestation
103
Sonographic apperance of spina bifida include:
lemon sign, banana sign, bulging within posterior contour of fetal spine and extrusion of the mass of vertebral column.
104
Any gut herniation greater than __ should be considered suspcious and be followed for resolution after 11 weeks 5 days
6mm
105
When does the bladder become sonographically visable?
at 10 to 12 weeks gestation
106
What results in a very large bladder?
obstructive uropathy, especially at the level of urethra
107
What is the most common ovarian mass seen in first trimester pregnancy?
corpus luteum cyst
108
What hormone do corpus luteum cysts secrete?
progesterone
109
What does a typical corpus luteum cyst look like?
measures less than 5cm in diameter and does not contain any septations
110
Occationally, what does a corpus luteum cyst look like?
large, size greater than 10cm, internal septations and echogenic debris, color Doppler with ring of vascularity around it
111
As corpus luteums regress, at what age should they not be seen anymore?
16 to 18 weeks gestation
112
What does a hemorrhagic corpus luteum cyst look like>
fishnet septations, debris
113
Due to ____ ___, fibroids may increase in size throughout first trimester and early in second trimester.
estrogen stimulation
114
Rapid increase in fibroid size can cause what?
leads to necrosis and may cause significant pain
115
What can a growing fibroid do to a gestational sac?
compress it and cause spontaneous abortion
116
What do fibroids look like sonographically?
hypoechoic, echogenic, or isoechoic, poor acoustic attenuation, displacement of endometrium or uterus or both
117
How do you differentiate between a gestational sac and a pseudogestational sac?
a pseudogestational sac has no living embryo/yolk sac, centrally located within the endometrial cavity, homogeneous level echoes
118
The human chorionic gonadotropin (hCG) levels in gestational trophoblastic disease:
increase at a markedly higher rate than in a normal pregnancy
119
The most common site of an ectopic pregnancy is:
the ampullary portion of the fallopian tube
120
A fluid collection in the endometrium that stimulates the gestational sac of an early pregnancy is called:
pseudogestational sac
121
Theca lutein cysts are:
the largest of the functional cysts, associated with trophoblastic disease or hyperstimulation of the hCG
122
When the uterus empties itself of all products of conception, it is referred to as a(n):
complete abortion
123
What is the approximate hCG level when a gestational sac is first observed (transabdominally)?
1800 mIU/mL
124
All of the following statements regarding hydatidiform mole are true except:
a) a previous mole results in increased risk for recurrrence
b) it is associated with markedly elevated hCG levels
c) the sonographic appearance is similar to that of a degenerating myoma
d) although considered "tumors" of trophoblastic tissue, they are incapable of metastasizing
d) although considered "tumors" of trophoblastic tissue, they are incapable of metastasizing
125
Higher than normal levels of hCG are seen in which of the following conditions?
a) multiple gestation
b) corpus luteum cyst
c) ectopic pregnancy
d) anembryonic gestation
a) multiple gestation
126
Trophoblastic disease, which extends outside the uterus and spreads to the lungs or brain, is called:
choriocarcinoma
127
Increased levels of hCG may cause:
theca lutein cysts
128
In an early gestation, the gestational sac:
can be visualized transvaginally by 4wks and transabdominally by 6wks
129
The placenta develops from:
the portion of the trophoblast attached to the myometrium, the decidua basalis
130
During the first trimester, the developing embryo grows aproximately ___ every day.
1-2 mm
131
A patient with a positive serum hCG test presents with some bleeding. The LMP indicates 5 to 6wks of gestation. Sonography does not reveal a fetal pole. The MOST likely diagnosis is a(n):
a) hydatidiform mole
b) complete spontaneous abortion
c) ectopic pregnancy
d) normal intrauterine gestation, but too early to detect the fetal pole
d) normal intrauterine gestation, but too early to detect the fetal pole
132
In a patient with a complete spontaneous abortion, the MOST likely finding is a(n):
a) empty gestational sac with no evidence of decidua
b) embryo with no evidence of a heartbet
c) complex mass in the cul-de-sac
d) empty uterus with a decidual reaction
d) empty uterus with a decidual reaction
133
A patient presents with a closed cervical os and a distorted gestational sac in the lower uterine segment. This MOST likely represents a(n):
a) blighted ovum
b) complete spontaneous abortion
c) threatened abortion
d) inevitable abortion
c) threatened abortion
134
With respect to ectopic pregnancies, which of the following is TRUE?
a) an adnexal mass can usually be palpated
b) implantation in the interstitial portion of the tube is a common occurrence
c) cornual ectopic pregnancies may have dangerous prognoses
d) ectopic pregnancies cannot be carried past the first trimester
c) cornual ectopic pregnancies may have dangerous prognoses
135
An embryo presents with an outpouching from the anterior abdominal wall into the base of the umbilical cord. This is MOST likely to be:
a) gastroschisis
b) omphalocele
c) normal herniation of the fetal gut
d) umbilical hernia
c) normal herniation of the fetal gut
136
The type of twinning that occurs when two ova are fertilized is:
a) monozygotic twinning
b) dizygotic twinning
c) monochorionic and monoamniotic twinning
d) monochorionic and diamniotic twinning
b) dizygotic twinning
137
What usually happens to the hCG levels in 48hrs in the presence of an ectopic pregnancy?
hCG levels rise at a subnormal rate
138
A fluid collection in the endometrium that stimulates the gestational sac of an early pregnancy is called:
pseudogestational sac
139
Which of the following is not a sonographic finding of a hydatidiform mole?
a) theca lutein cysts
b) grapelike clusters throughout the uterus
c) homogeneous uterine texture
d) low-impedance, high-flow Doppler pattern
c) homogeneous uterine texture
140
The thin decidua overlying the portion of the gestational sac facing the endometrial cavity is the:
decidua vera
141
The formula used to calculate gestational age from CRL is:
GA = CRL + 6.5
142
What occurs when there is death of the embryo or fetus, but the gestational parts remain in utero?
incomplete or missed abortion
