Chapter 31 - Multiple Gestations Flashcards
An abnormally developed twin that has as absent upper body and no heart; also referred to as parasitic twin; also referred to as twin-reversed arterial perfusion sequence
Acardiac twin
The inner sac that contains the embryo and amniotic fluid; echogenic curvilinear structure that may be seen during the first trimester within the gestational sac
Amnion
Related to the number of amnions in a multiple gestation
Amnionicity
Fluid-filled space, created by the amnion, surrounding surrounding the developing embryo or fetu
Amniotic sac
Vascular connections
Anastomoses
The condition of having a deficient number of red blood cells
Anemia
The outer membrane of a gestation that surrounds the amnion and developing embryo
Chorion
Relates to the number of chorions and the type of placentation in a multiple gestation
Chorionicity
The division of a cell
Cleavage
Monoamniotic, monochorionic twins that are attached at the head, thorax, abdomen, or lower body
Conjoined twins
Twins joined at the cranium
Cranipagus
Having two amniotic sacs
Diamniotic
Having two placentas
Dichorionic
Having two placentas and two amniotic sacs
Dichorionic
Diamniotic
Asymmetric fetal weight between twins
Discordant Fetal growth
Two ova are fertilized by two sperms
Dizygotic
A treatment that uses lasers to separate abnormal placental vascular connections between twins that are suffering from twin-twin transfusion syndrome
Endoscopic Guided laser Photocoagulation
The death of one fetus in twin pregnancy that is maintained throughout the pregnancy; actually means paperlike fetus
Fetus Papyraceus
Twins that result from the fertilization of two separate ova and have dissimilar characteristics
Fraternal Twin
An abnormal accumulation of fluid at least two fetal body cavities
Hydrops
A shortage of oxygen or decreased oxygen in the blood
Hypoxia
Twins that result from the split of a single zygote and share the same genetic structure
Identical twins
A triangular extension of the placenta at the base of the membrane is indicative of a dichorionic diamniotic pregnancy; also referred to as the delta sign or the twin peak sign
Lambda Sign
Having one amniotic sac
Monoamnitoic
Having one chorion
Monochorinic
Having one placenta and two amniotic sacs
Monochorionic
Diamniotic
Having one placenta and one amniotic sac
Monochorionic Monoamniotic
Coming from one fertilized ovum or zygote
Monozygotic
The relative frequency of occurrence of a disease
Morbidity
The rate of actual deaths
Motality
Conjoined twins attached at the abdomen
Omphalopagus
An unfertilized egg
Ovum
Formation or structure of a placenta, structural organization, and mode of attachment of fetal to maternal tissues during placental formation
Placentation
The development of a cystic cavity within within the cerebrum; may be the result of an intraparenchymal hemorrhage
Porencephaly
Conjoined twins joined back-to-back in the sacral region
Pyopagus
36
A single developing fetus
Singleton pregnancy
Dead at birth
Stillborn
When a twin fetus, suffering from twin-twin transfusion syndrome, experiences severe oligohydroamnios and is closely adhered to the uterine wall
Stuck twin
Type of amniocentesis used to remove a large amount of amniotic fluid around a fetus suffering from polyhydroamnios
Therapeutic Amniocentesis
Conjoined twins attached at the chest
Thoracopagus
When vascular products travel from a demised twin to the surviving twin by means of the common vascular channels within the shared placenta
Twin Embolization Syndrome
Shunting of venous or arterial blood from one twin to another through placental circulation
Twin-twin transfusion syndrome
The death and reabsorption of a twin
Vanishing twin
Relates to the number of zygotes (fertilized ova)
Zygosity
The cell formed by the union of two gametes; the first stage of fertilized ovum
Zygote
patients with multiple gestations may present with the clinical indication of large for dates and also an elevated ______ blood level compared to a singleton pregnancy
hcG
twins have a 4x higher risk of fetal ____ and a 6x higher neonatal ______ rate
mortality
morbidity
what has been shown to increase the probability of multiple gestations:
a maternal history of multiple gestations, ART (assisted reproductive therapy, ovulation induction drugs, advanced maternal age, and maternal obesity
twins can be either _____ or ________
monozygotic
dizygotic
monozygotic twins arise from a ___________ whereas dizygotic twins form from __________
single zygote
two speerate zygotes
the ________, the structure that forms the placenta, develops before the amnion
chorion
twins who have one shared placenta are referred to as ______ whereas twins who have two separate placentas are called __________
monochorionic
dichorionic
___________ refers to how many amnions or amniotic sacs are present
amnionicity
twins who share the same amniotic sac are referred to as __________, whereas twins who have their own individual amniotic sac are ________
monoamniotic
diamniotic
_________ are the most common form of twinning, arise from two separate fertilized ova
dizygotic
dizygotic twins are referred to as ________ because they have their own genetic structure
fraternal twins
dizygotic twinning always results in __________, there are two placentas, there must be two amnions
diachronic diamnotic twins
_____________ arise from a single zygote that splits
monozygotic twins `
monozygotic twins are always:
identical twins
three categories of monozygotic twins:
monochorionic diamniotic
dichorionic diamniotic
monochorionic monoamniotic
result of dichorionic diamniotic twins: (dizygotic)
description: two separate fertilized ova
appearance: fraternal
(each twin has their own chorionic and amniotic sac)
result of monochorionic diamniotic twins: (monozygotic)
description: one zygote splits between 4 and 8 d
appearance: identical
(identical twins who share a placenta (monochorionic) but each have their own inner sac (diamniotic)
result of dichorionic diamniotic twins: (monozygotic)
description: one zygote splits prior to day 4
appearance: identical
result of monochorionic monoamniotic: (monozygotic)
description: one zygote splits late
appearance: identical
(twins are those who share both the chorionic and amniotic sacs)
most common form of monozygotic twins:
monochorionic diamniotic
most common form of monozygotic twins:
monochorionic monoamniotic twins
because of the shared amniotic sac, monochorionic monoamniotic carries the additional risk of:
conjoined twins
the presence of one yolk sac and two fetuses is indicative of a __________ gestation, whereas the presence of two yolk sac is indicative of a __________ gestation
monoamniotic
diamniotic
a triangular extension of the placenta at the base of the diving membrane is indicative of a dichorionic diamniotic pregnancy. this is referred to as:
twin peak sign, lambda sign, or delta sign
with a monochorionic diamniotic pregnancy, the membrane will be thin and seen separating at the junction point with the placenta, a sonographic sign referred to as the:
“T sign”
if the twins are different sexes, then one can assume that the twins are:
Dichorionic
same-sex fetuses that have a single placenta and a thin membrane separating them are almost certainly:
Monochorionic
a complication that carries a high mortality rate for monochorionic twins is:
Twin-twin transfusion syndrome (TTTS)
What is TTTS?
the twin that shunts blood to the other is called the “donor” twin and is often smaller than the twin receiving extra blood, the “recipient twin”
with TTTS, the donor twin will suffer from ____________ and the recipient twin experiences _______
anemia and growth restriction
hydrops and congestive heart failure
treatment options for TTTS:
therapeutic amniocentesis and endoscopic-guided laser photocoagulation of the communicating placental vessels
stuck twin refers to:
severe oligohydramnios surrounding a twin that appears to be closely associated with the uterine wall
sonographic findings of twin-twin syndrome: (TTTS) (5)
- monochorionic twinning
- discordant fetal growth
- oligohydramnios around the donor twin
- polyhydramnios around recipient twin
- recipient may be hydropic
abnormal anastomoses (a cross-connection between adjacent channels, tubes, fibers, or other parts) of placental vessels may result in:
a parasitic twin or acardiac twin- this is considered to be a severe form of TTTS
acardiac twinning may also be referred to as ___________ or __________
TRAP syndrome (twin-reversed arterial perfusion)
or
acardiac parabiotic twinning
with acardiac twinning, there is one normal fetus, “__________” and an abnormally developed fetus containing ___________
“pump twin”
no heart
sonographic findings of acardiac twin: (2)
- normal pump twin
- acardiac twin - absent upper body, absent heart, hydrops
the most common forms of conjoined twinning are ________ and __________ which is attached at the chest and
abdomenthoracopagus and omphalopagus
twin embolization syndrome can result from the death of a ___________ twin
monochorionic
________ and ______ are common in the survivor of twin embolization syndrome
hydrocephalus and porencephaly
mothers expecting multiple gestations have an increased risk of developing?
reeclampsia and anemia
(preeclampsia-high blood pressure during pregnancy)
the median gestational age of delivery for twins is:
35 weeks
infants born with low birth weight, and specifically before 32 weeks’ gestation, often suffer from ___________ with episodes of _______
pulmonary hypoplasia- (incomplete development of the lungs)
hypoxia- (body does not receive enough oxygen)
which of the following is not a sonographic sign of a dichorionic diamniotic gestation?
a. twin peak sign
b. lambda sign
c. delta sign
d. T sign
D
twins that have the threat of being conjoined are:
a. monochorionic monoamniotic
b. monochorionic diamniotic
c. dizygotic
d. dichorionic diamniotic
A
which of the following would be a newborn most likely suffer from if he or she were born prior to 32 weeks as a result of multiple gestation complications?
a. ascites
b. pulmonary hypoplasia
c. amnionitis
d. preeclampsia
B
the inner membrane surrounding the fetus is referred to as the:
a. placenta
b. chorion
c. amnion
d. yolk sac
C
twins that result from the fertilization of two separate ova are called:
a. diamniotic
b. dizygotic
c. monozygotic
d. monochorionic
B
what condition is pregnant-induced maternal high blood pressure and excess protein in the urine after 20 weeks’ gestation?
a. gestational diabetes
b. preeclampsia
c. porencephaly
d. maternal mirror syndrome
B
the outer membrane of the gestation is referred to as the:
a. placenta
b. chorion
c. amnion
d. yolk sac
B
which of the following would not increase the likelihood of multiple gestations?
a. gestational diabetes
b. maternal age > 40 yrs
c. maternal history of twins
d. ART
A
twins whose bodies are connected at some point are said to be:
a. fraternal
b. conjoined
c. identical
d. stuck
B
the term that indicates the presence of two separate amniotic sacs is:
a. dichorionic
b. bichorionic
c. monoamniotic
d. diamniotic
D
Twins having two placentas and one amniotic sac are referred to as:
a. monochorionic diamniotic
b. monoamniotic dichorionic
c dichorionic monoamniotic
d. this does not occur
D
what is it called when a twin fetus, suffering from TTTS, experiences severe oligohydramnios and becomes closely adhered to the uterine wall?
a. acardiac monster
b. vanishing twin
c. acardiac twin
d. stuck twin
D
which term relates the number of amniotic sacs?
a. chorionicity
b. placentation
c. amnionicity
d. embryology
C
twins have one placenta and one amniotic sac are referred to as:
a. dichorionic monoamniotic
b. dichorionic diamniotic
c. monochorionic diamniotic
d. monochorionic monoamniotic
D
which term relates the number of placentas?
a. chronionicity
b. zygocity
c. amnionicity
d. cleavage
A
identical twins result from:
a. monozygotic twinning
b. dizygotic twinning
c. heterotopic pregnancies
d. monochorionic pregnancies
A
the sonographic examination of twins reveals a triangular extension of the placenta at the base of the membrane. this finding is indicative of:
a. monochorionic monoamniotic twins
b. monochorionic diamniotic twins
c. dichorionic diamniotic twins
d. monochorionic diamniotic twins
C
asymmetry in fetal weight between twins is indicative of:
a. discordant growth
b. preeclampsia
c. dichorionic diamniotic twinning
d. intrauterine infections
A
twins having two placentas and two amniotic sacs are referred to as:
a. monochorionic diamniotic
b. biamniotic dichorionic
c. dichorionic diamniotic
d. dichorionic biamniotic
C
typically, the first sonographic manifestation of TTTS is:
a. oligohydramnios
b. polyhydramnios
c. dichorionic twinning
d. discordant fetal growth
D
conjoined twins that are attached at the abdomen are referred to as:
a. omphalopagus
b. thoracopagus
c. ileopagus
d. craniopagus
A
monozygotic twins result from:
a. a single zygote that splits
b. two zygotes that are fertilized by the same sperm
c. two morulla
d. a single zygote that is fertilized by two sperm
A
the demise of a twin during the second or third trimester can lead to:
a. TTTS
b. twin embolization syndrome
c. twin peak sign
d. acardiac twinning
B
the term that indicates the presence of two separate placentas is:
a. dichorionic
b. bichorionic
c. monoamniotic
d. diamniotic
A
what is a treatment that separates abnormal placental vascular connections between twins that are suffering from TTTS?
a. cleavage-laser resection treatment
b. endoscopic-guided laser photocoagulation
c. endemic translocation of the placental vessels
d. circumvallate resection of shared placental vasculature
B
the shunting of blood from one twin to the other is termed:
a. TTTS
b. twin embolization syndrome
c. twin peak sign
d. conjoined twins
A
factors that increase the likelihood of having multiple gestations include all of the following except:
a. advanced maternal age
b. ovulation induction drugs
c. poor nutritional state
d. maternal predisposition for twins
C
TRAP syndrome may also be referred to as:
a. TTRS
b. vanishing twin syndrome
c. twin embolization syndrome
d. acardiac twinning
D
which of the following can occur as a result of dizygotic twinning?
a. monochorionic diamniotic twins
b. monochorionic monoamniotic twins
c. dichorionic diamniotic twins
d. all of the above
C
the abnormal twin in acardiac twinning is also referred to as the:
a. pump twin
b. parasitic twin
c. stuck twin
d. vanishing twin
B
the twin that will appear larger in TTTS is the:
a. donor
b. recipient
c. both will be the same
d. both will be demised
B
fraternal twins result from:
a. monozygotic twinning
b. dizygotic twinning
c. heterotopic pregnancies
d. monochorionic pregnancies
B
what is the term for conjoined twins attached at the sacral region?
a. sacralpagus
b. omphalopagus
c. pyopagus
d. thoracopagus
C
which of the following can occur as a result of monozygotic twinning?
a. monochorionic diamniotic twins
b. monochorionic monoamniotic twins
c. dichorionic diamniotic twins
d. all of the above
D
the most common for of monozygotic twins is:
a. monochorionic diamniotic
b. dichorionic monoamniotic
c. monochorionic monoamniotic
d. none of the above
A
all of the following complications are associated with multiple gestations except:
a. preterm delivery
b. high birth weight
c. maternal anemia
d. maternal preeclampsia
B
acardiac twinning results from:
a. poor maternal nutrition
b. dizygotic gestations
c. abnormal links between the placental vessels
d. twin embolization syndrome
C
ovulation induction drugs not only increase the likelihood of multiple gestations, but also increase the likelihood of:
a. maternal diabetes
b. ovarian prolapse
c. heterotopic pregnancies
d. choriocarcinoma
C
which form of monozygotic twinning is least common?
a. monochorionic diamniotic
b. monochorionic monoamniotic
c. dichorionic diamniotic
d. dichorionic biamniotic
B
the demise of a twin can lead to the development of neurologic complications in the living twin as a result of:
a. twin embolization syndrome
b. TTTS
c. TRAP syndrome
d. dichorionicity
A