Assessment of the First Trimester Flashcards
(49 cards)
1
Q
decidua parietalis / decidua vera
A
results from hormonal influence on the uninvolved endometrial tissue
2
Q
gestational sac
A
- Beta hCG of 1000 mIU/mL should demonstrate a GS transvaginally
- transabdominal: 5mm mean sac diameter 5-6 weeks
- transvaginal: 2-3mm about 4-5 weeks
3
Q
sonographic findings of gestational trophoblastic neoplasm
A
- moderately echogenic soft tissue uterine mass
- cystic structures within mass
- vascular flow
- bilateral theca lutein cysts
- possible adjacent fetus
4
Q
chorion frondosum
A
the portion of the chorion that develops into the fetal portion of the placenta
5
Q
abdominal wall
A
- physiological herniation of the fetal bowel into the umbilical cord
- bowel returns into abdomen, adn herniation resolves by the eleventh gestational week
6
Q
What should be seen during the 6th week?
A
- MSD 15-20mm
- yolk sac visualized
- c-shaped embryo approx 5mm
- heart rate present
7
Q
cornual ectopic
A
- laterally placed gestational sac
- myometrium incompletely surrounds the GS
- highly vascular location
8
Q
Nuchal Translucency
A
- first trimester screening for chromosomal abnormalities
- maximum thickness of the subcutaneous translucency betweem the skin and soft tissue overlying the cervical spine is measured
- calipers are placed on the hyperechoic lines, not in the nuchal fluid, from inner-to-inner borders
- exceeding 3 mm is abnormal
9
Q
where does the zygote form?
A
in distal fallopian tube
10
Q
What should be seen by the 5th week?
A
- MSD 10mm
- yolk sac seen transvaginally
- may see embryonic disc and may wee cardiac activity
11
Q
what are the risk factors for an ectopic?
A
- pelvic infection
- IUD
- oviduct surgery
- infertility treatment
- endometriosis
- previous ectopic
12
Q
decidua basalis
A
portion of the endometrium on which the implanted conceptus rests
13
Q
skeletal system
A
- vertebral bodies and ribs are forming at 6 weeks
- arms and legs are forming at 7 weeks
- ossification of the vertebral bodies and rib cartilage at 9 weeks
- long bones form during the 10 week
14
Q
heterotopic pregnancy
A
one IUP and one extrauterine
differential: bicornuate uterus pregnancy in both horns, IUP with complex corpus luteal cyst
15
Q
morula
A
solid mass of cells formed by cleavage of a fertilized ovum
16
Q
The embryo unfolds and the midgut has herniated during what week?
A
8th week
17
Q
What is demonstrated during 12th week?
A
- midgut returned to abdominal cavity
- skeletal body
- fluid in stomach
- yolk sac no longer seen
18
Q
chorionic plate
A
the part of the chorionic membranethat covers the placenta
19
Q
crown-rump length
A
- measured until 12th gestational week
- most accurate method of dating a pregnancy
- sagittal measurement of the embryo or fetus from the top of the head to the bottom of the rump
- lower extremities are not included in the measurement
- length increases approximately 1 mm/day
20
Q
What should be seen by the 4th week?
A
thickening of endometrium
MSD 2-3mm
21
Q
decidua capsularia
A
decidua that covers the surface of the implanted conceptus
22
Q
embryological age
A
length of time based from conception.
weeks 6-10
23
Q
decidua parietalia
A
decidua exclusive of the area occupied by the implanted conceptus; aka decidua vera
24
Q
embryo
A
- embryonic period extends from the sixth through the tenth gestational weeks
- transabdominal: usually detected within an MSD >25mm
- transvaginal: usually detected in an MSD >16mm
25
pseudocyesis
* false pregnancy
* psychological codition
* normal nongravid uterus
* normal adnexa
26
The 10th week has what sonographic findings?
* muscle movement has begun
* hyperechoic choroid plexuses
* rhombencephalon demonstrated
27
mean sac diameter
establishes gestional age before visualization of an embryonic disc
MSD(mm)=length+height+width/3
28
when is organogenesis generally completed?
by the 10th week
29
decidua basalis
develops where the blastocyst implants
maternal contribution to placenta
30
gestational trophoblastic neoplasm
* abnormal proliferation of the trophoblast
* hydatid swelling in a blighted ovum
* trophoblastic changes in retained placental tissue
31
what implants in the endometrium?
blastocyst
32
anembryonic (blighted ovum)
* zygote develops into a blastocyst but inner cell mass fails to develop
* differential: missed abortion or pseudogestational sac
33
complete abortion
miscarriage
differential: ectopic or early IUP
34
clinical findings of pseudocuesis
* nausea and vomiting
* abdominal distention
* amenorrhea
* negative pregnancy test
* differential: recent complete miscarriage
35
differential of gestational trophoblastic neoplasm
* incomplete abortion
* degenerating fibroid
* adenomyosis
36
cranium
* prosencephalon- forebrain
* mesencephalon- midbrain
* rhombencephalon- hindbrain
37
fallopian tube ectopic
* 95% are located in the fallopian tube
* typically in ampulla
* complex adnexal mass
* cul-de-sac fluid
* may display an extrauterine gestational sac with or without embryo
38
decidua capsularis
closes over and surrounds the blastocyst
39
clinical findings of gestational trophoblastic neoplasm
* bleeding
* hyperemesis
* elevated beta hCG
* large for dates
* no heart tones
* low maternal AFP
* preeclampsia
40
subchorionic hemorrhage
* low pressure bleed from implant of blastocyst
* becomes more anechoic with time
* differential: nonviable twin, incomplete abortion, placenta abruption
41
cardiovascular system
* first system to function in the embryo
* four heart chambers are formed by the eighth gestational week
* cardiac motion as early as 5.5 weeks
42
cardiac activity
* first system to function in embryo
* should be identified by 6 weeks, as early as 5.5 weeks
* 110-115 bpm before 6 weeks
* 120-160 bmp after 6 weeks
43
Amnion
* attaches to embryo at the umbilical cord insertion.
* expands with accumulation of amniotic fluid and growth of the embryo
* obliterates chorionic cavity by 16th week
44
corpus lutem during pregnancy
* secretes progestrone before placental circulation
* usually measures
* hypervascular periphery (ring of fire)
* differential: ectopic or endometrium
45
yolk sac
* provides nutrition to the embryo
* earliest structure visualized in the gestational sac
* attached to the embryo by the vitelline duct
* inner-to-inner border diameter should not exceed 6mm
* transabdominal: evident within an MSD of 20mm
* transvaginal: evident within an MSD of 8mm
46
during what week do limb buds appear?
7th week
CRL 1 cm
47
how long does it take fertilization to implant?
5 to 7 days
48
incomplete abortion
* retained products of conception
* thick and complex endometrium
* intact gestational sac with nonviable embryo
* collapsed GS
* differential: ectopic or endo dysplasia
49
human chorionic gonadotropian
* produced by the trophoblastic cells of the developing chorionic villi
* normally doubles every 30 to 48 hours during the first 6 weeks of pregnancy
* peaks at the tenth gestational week 100,00 mIU/mL
* declines after tenth week and levels out at about 18 weeks 5000mIU/mL
* gestaional sac should be identified transvaginally after the hCG levels reach 1000 mIU/mL and as early as 500 mIU/mL
