OB/GYN Registry Review Part 4 Flashcards
_____ twinning will always be:
dichorionic/diamniotic
early division <4 days results in:
dichorionic/diamniotic
The most common division is between __-__ days
4
8
Division between 4 and 8 days results in:
monochorionic/diamniotic
Late division >8 days results in:
monochorionic/monoamniotic
two completely separate gestational sacs within the uterine cavity in the first trimester
dichorionic
Twin peak (labda or delta sign)
dichorionic/diamniotic
thin membrane inserting like a T into placenta which means one shared placenta T sign
monochorionic/diamniotic
Monochorional twins share one placenta so there’s increased risk of ____ and ____
fetal shunting
growth issues
fetal shunting through vessels in the placenta
Twin to Twin Transfusion syndrome
Donor twin gives blood to other, eventually suffering from ____ and ____ in TTTS
anemia
IUGR
The recipient twin receives too much blood and can suffer from _____ and ____ due to the overload of blood going to the heart in TTTS
hydrops
CHF
1st initial sonographic indication of TTTS
discordant fetal growth
The donor twin in TTTS signs:
smaller/IUGR
oligohydramnios
anemia
The recipient twin in TTTS signs:
larger
polyhydramnios
hydrops/CHF
most severe type of TTTS
stuck twin
Oligohydramnios is so severe that the donor twin appears to be stuck to the side of the uterine wall
Stuck twin (TTTS)
Acardiac twinning is also known as ____
TRAP sequence
TRAP sequence is:
twin reversed arterial perfusion syndrome
abnormal anastamosis of placental vessels that support the growth of parasitic or acardiac twin
TRAP sequence
One normal fetus and one abnormally developed fetus with no heart
TRAP sequence
The pump twin in TRAP sequence maintains:
the growth of the parasitic twin
The pump twin in TRAP sequence has a mortality rate of __% secondary to polyhydramnios and prematurity.
50
The acardiac twin in TRAP sequence demonstrates:
absent upper body, absent heart, and hydrops
Conjoined twins only happen in;
monochorionic/monoamniotic twins
Occurs when zygote splits >13 days
conjoined twins
Most common types of conjoined twins
thoracopagus
omphalopagus
thoracopagus
conjoined at the chest
omphalopagus
conjoined at the abdomen
_____ twins have a greater chance of survival in cause of one twin demise, especially earlier on in the first trimester
dichorionic
fetal death in 1st trimester and is maintained, not reabsorbed. May eventually become vanishing
fetus papyraceus
death of a twin in the early 1st trimester and is reabsorbed
vanishing twin
______ fetal demise will often lead to death of other twin
monochorionic
Fetal demise in the second trimester of monochorionic can lead to:
twin embolization syndrome
demised twin begins to breakdown and vascular products can travel through common vascular channels with shared placenta.
twin embolization syndrome
The _____ and ____ are usually affected in twin embolization syndrome
central nervous system
kidneys
The normal placenta is __-__ cm thick
2
4
The major function of the placenta is an ____ organ
excretory
The _____ exchanges gases and wastes products with nutrients and oxygen and is the means of nutrition and respiration.
placenta
The maternal side of the placenta
decidua basalis
The fetal side of the placenta
chorion frondosum
functional unit of placenta
lobes of chorionic villi termed cotyledons
2 discs of equal size joined together by an isthmus of placental tissue
bilobed
additional small lobe separate from the main placental mass but connect by vascular connections. No placental tissue connection
accessory lobe/succenturiate lobe
curled up placental contour appearing appearing as a shelf. Curled edges, do not lay flat or smooth along wall. Increased risk of abnormal placental development and future abruption
circumvallate placenta
pools of maternal venous blood. Sonolucent areas within placental mass. Will not fill in with color, but can be “swirling” in B-mode
venous lakes/maternal lakes/placental lakes/lacunae
Advanced maturation of the placenta can be indications of maternal complications leading to:
placental insufficiency
asymmetrical IUGR
Grade 0 placenta
homogenous, smooth texture. No indentations in the chorionic plate. Smooth borders (1st tri to early 2nd tri)
Grade 1 placenta
subtle indentations in chorionic plate, small random hyperechoic foci (2nd tri to early 3rd tri)
Grade 2 placenta
larger, comma-like indentations alter chorionic plate, larger calcifications in basal plate (late 3rd tri)
Grade 3 placenta
post dates/advanced. Complete indentations chorionic to basal plate. Irregular calcifications with shadowing. Related to drug abuse and preeclampsia. may cause IUGR if early gestation
-previa
presenting/before
placenta is implants within the LUS and covers/near to internal os
placenta previa
most likely cause of painless vaginal bleeding in 2nd/3rd trimester
placenta previa
Placenta previa can only by diagnosed __ weeks onward due to possible placental migration
20
internal os is completely covered by placental tissue
complete placenta previa
edge of placenta touches internal os
marginal placenta previa
edge of placenta is within 2cm of internal os
low-lying placenta
general term for abnormal adherence of placenta to myometrium
placenta accreta
loss of basal plate or myometrial/serosal layer, multiple placental lacunae, and increased peripheral vascularity
placenta accreta
Most common (accreta, increta, or percreta)
accreta
Placenta _____ invades the myometrium
increta
Placenta ____ penetrates through the uterus and breach serosal layer
percreta
premature separation of placenta from uterine wall
placental abruption
hypoechoic or anechoic region between placenta and uterine wall at level of basal plate
placental abruption
most severe abruption, entire retroplacental hematoma
complete placental abruption
A few centimeters of separation (abruption)
partial
placental edge, lifting the chorionic membrane from the wall (abruption)
marginal
most common placental tumor
chorioangioma
Most common location of chorioangioma
adjacent to umbilical cord insertion at placenta
