Ch. 31 Multiple Gestations

Question 1

shunting of venous or arterial blood from one twin to another through placental circulation

Answer 1

twin–twin transfusion syndrome (TTTS)

Question 2

asymmetric fetal weight between twins

Answer 2

discordant growth

Question 3

an abnormal accumulation of fluid in at least two fetal body cavities

Answer 3

hydrops

Question 4

type of amniocentesis used to remove a large amount of amniotic fluid around a fetus suffering from polyhydramnios

Answer 4

therapeutic amniocentesis

Question 5

a treatment that uses lasers to separate abnormal placental vascular connections between twins that are suffering from twin–twin transfusion syndrome

Answer 5

endoscopic-guided laser photocoagulation

Question 6

when a twin fetus, suffering from twin–twin transfusion syndrome, experiences severe oligohydramnios and is closely adhered to the uterine wall

Answer 6

Stuck twin

Question 7

Sonographic Findings of ___________

1.Monochorionic twinning
2.Discordant fetal growth
3.Oligohydramnios around donor twin
4.Polyhydramnios around recipient twin
5.Recipient may be hydropic

Answer 7

Twin–Twin Transfusion Syndrome

Question 8

With TTTS, the twin that shunts blood to the other is called the “_______” twin and is often _________than the twin receiving extra blood, the “_______” twin.Treatment options include therapeutic amniocentesis and endoscopic-guided laser photocoagulation of the communicating placental vessels.

Answer 8

donor; smaller; recipient

Question 9

A complication that carries a high mortality rate for __________twins is twin–twin transfusion syndrome (TTTS)

Answer 9

monochorionic

Question 10

With TTS, the donor twin often suffers from ________ and ________, whereas the recipient experiences _______ and __________

Answer 10

anemia and growth restriction; hydrops and congestive heart failure

Question 11

discordant growth, which is described as a _____ to ______ ________ in the estimated fetal weight of the smaller fetus compared to the larger.

Answer 11

15% to 25% reduction

Question 12

vascular connections

Answer 12

anastomoses

Question 13

an abnormally developed twin that has an absent upper body and no heart

Answer 13

acardiac twin

Question 14

________ refers to severe oligohydramnios surrounding a twin that appears to be closely associated with the uterine wall

*seen with TTTS

Answer 14

Stuck twin

Question 15

Abnormal anastomoses of placental vessels may result in a parasitic twin or _______. This is considered to be a severe form of TTTS.

Answer 15

acardiac twin

Question 16

Acardiac twinning may also be referred to as ____________ sequence or acardiac parabiotic twinning.

Answer 16

twin-reversed arterial perfusion (TRAP)

Question 17

another name for acardiac twinning

Answer 17

twin-reversed arterial perfusion (TRAP)

Question 18

Sonographic Findings of ________

1.Normal pump twin
2.Acardiac twin—absent upper body, absent heart, and hydrops

Answer 18

Acardiac Twin

Question 19

With acardiac twinning, there is one normal fetus, the “_________,” and an abnormally developed fetus containing no________. The normal fetus maintains the growth of the parasitic twin. Abnormally developed fetus also has absent upper body, and hydrops

Answer 19

pump twin; no heart

Question 20

The pump twin has a perinatal mortality of 50% to 55%, secondary to _________ and ________.

Answer 20

polyhydramnios and prematurity

Question 21

Conjoined twins can result from ____________twinning.

Answer 21

monochorionic monoamniotic

Question 22

conjoined twins attached at the chest

Answer 22

thoracopagus

Question 23

conjoined twins attached at the abdomen

Answer 23

omphalopagus

Question 24

The most common forms of conjoined twinning are _______ and _________, which is the attachment at the chest and abdomen, respectively.

Answer 24

thoracopagus;omphalopagus

Question 25

twins joined at the cranium

Answer 25

craniopagus

Question 26

conjoined twins joined back-to-back in the sacral region

Answer 26

pyopagus

Question 27

dead at birth

Answer 27

stillborn

Question 28

Conjoined twins may also be joined at the cranium (___________) or back-to-back in the sacral region, which is termed __________.

Answer 28

(craniopagus); pyopagus

Question 29

The prognosis is poor for conjoined twins. They have a 40% chance for being _________, with many dying within the first 24 hours.

Answer 29

stillborn

Question 30

The death of a twin, and subsequent reabsorption of the embryo during the first trimester, is termed a __________

Answer 30

vanishing twin

Question 31

the death and reabsorption of a twin

Answer 31

vanishing twin

Question 32

the death of one fetus in a twin pregnancy that is maintained throughout the pregnancy; actually means paperlike fetus

Answer 32

fetus papyraceus

Question 33

If the fetus dies in the first trimester and is maintained throughout the pregnancy, it is referred to as ______________. With dichorionic twins, the surviving twin is rarely affected by the death of the other. However, the death of a _________ twin during the first trimester frequently leads to the death of the other twin.

Answer 33

fetus papyraceus; monochorionic

Question 34

The death of a ________ twin during the second or third trimester can lead to life-threatening problems in the surviving twin. Potential troubles exist as a consequence of the breakdown of the demised twin.

Answer 34

monochorionic

Question 35

Vascular products, as a result of the breakdown of tissues, travel from the demised twin to the surviving twin by means of the common vascular channels within the shared placenta, a complication known as __________

Answer 35

twin embolization syndrome

Question 36

Twin embolization syndrome can result from the death of a __________ twin.

Answer 36

monochorionic

Question 37

when vascular products travel from a demised twin to the surviving twin by means of the common vascular channels within the shared placenta

Answer 37

twin embolization syndrome

Question 38

the development of a cystic cavity within the cerebrum; may be the result of an intraparenchymal hemorrhage

Answer 38

porencephaly

Question 39

In the death of a monochorionic twin, particularly the __________ and the __________ are affected in the surviving twin, with a documented 25% risk of death or neurologic damage for the survivor. Intracranial abnormalities such as hydrocephalus and porencephaly are common in the survivor as well

Answer 39

central nervous system and kidnyes

Question 40

Triplet pregnancies can manifest with different combinations of ________ and ________. For example, triplets can be trichorionic triamniotic and dichorionic triamniotic. Most triplet and quadruplet pregnancies result from the use of ovulation induction or in vitro fertilization

Answer 40

chorionicity and amnionicity;

Question 41

Unfortunately, multiple gestations beyond twins have an increased likelihood of discordant growth, miscarriage, and perinatal death. When assisted reproduction is used, resulting in a high number of multifetal pregnancies, multifetal __________ may be used. With sonographic guidance, a needle punctures the fetal heart and potassium chloride is injected.

Answer 41

reduction

Question 42

pregnancy-induced maternal high blood pressure and excess protein in the urine after 20 weeks’ gestation

Answer 42

preeclampsia

Question 43

the condition of having a deficient number of red blood cells

Answer 43

anemia

Question 44

underdevelopment of the lungs

Answer 44

pulmonary hypoplasia

Question 45

a shortage of oxygen or decreased oxygen in the blood

Answer 45

hypoxia

Question 46

Mothers expecting multiple gestations have an increased risk of developing _________ and ________. The risk for _______ delivery is increased 7 to 10 times more compared to a singleton pregnancy, with an associated ______ birth weight. The median gestational age of delivery for twins is 35 weeks, and for triplets and beyond, the gestational age of delivery is even earlier.

Answer 46

preeclampsia and anemia; preterm; low; 35 weeks

Question 47

Infants born with low birth weight, and specifically before 32 weeks’ gestation, often suffer from _____________ with episodes of ________. _______ at the time of birth can cause tiny, fragile blood vessels within the immature brain to rupture, leading to intracranial hemorrhage and possible irreversible neurologic complications or death.

Answer 47

pulmonary hypoplasia; hypoxia; Hypoxia

Question 48

Terminology associated with conjoined twins Conjoined Terminology: __________ Area of Union: Joined at the head

Answer 48

Craniopagus

Question 49

Terminology associated with conjoined twins Conjoined Terminology: __________ Area of Union: Joined at the thorax (chest)

Answer 49

Thoracopagus

Question 50

Terminology associated with conjoined twins Conjoined Terminology: __________ Area of Union: Joined at the abdomen

Answer 50

Omphalopagus

Question 51

Terminology associated with conjoined twins Conjoined Terminology: __________ Area of Union: Joined at the pelvis (spine connected at a 180 degree angle, facing away from one another)

Answer 51

Ischiopagus

Question 52

Terminology associated with conjoined twins Conjoined Terminology: __________ Area of Union: Joined at the sacral region or back-to-back

Answer 52

Pyopagus

Question 53

With a ______________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.”

Answer 53

monochorionic diamniotic

Question 54

If separate placentas are noted, then the pregnancy must be ___________. In addition, noting a triangular extension of the placenta at the base of the dividing membrane is indicative of a _____________pregnancy. This is referred to as the twin peak sign, lambda sign, or delta sign

Answer 54

dichorionic diamniotic

Question 55

a triangular extension of the placenta at the base of the membrane and is indicative of a dichorionic diamniotic pregnancy; also referred to as the delta sign or twin peak sign

Answer 55

lambda sign, twin peak sign, delta sign

Question 56

If the twins are _______ 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 __________

Answer 56

different; monochorionic

Question 57

The presence of _____ yolk sac and two fetuses is indicative of a monoamniotic gestation, whereas the presence of ______ yolk sacs is indicative of a diamniotic gestation.

Answer 57

one; two

Question 58

During the first trimester, ________ twins will have a thick membrane separating the two amniotic sacs, whereas __________twins will have a thin membrane or no membrane at all between them

Answer 58

dichorionic; monochorionic

Question 59

Monozygotic twins arise from a _______ zygote that splits. Thus, monozygotic twins are always _________ twins because they share their design from only one fertilized egg. It depends on the time at which this division, or ________, takes place as to how many placentas and amnions may be present with monozygotic twins

Answer 59

single; identical; cleavage

Question 60

twins that result from the split of a single zygote and share the same genetic structure

Answer 60

identical twins

Question 61

the division of a cell

Answer 61

cleavage

Question 62

What are the 3 types of monozygotic twins?

Answer 62

(i) monochorionic diamniotic, (ii) dichorionic diamniotic, and (iii) monochorionic monoamniotic

Question 63

_______________twins are the most common form of monozygotic twins.

Answer 63

Monochorionic diamniotic

Question 64

It is important to note that when two fetuses share the _______placenta, complications are more likely to occur.

Answer 64

same

Question 65

The least probable monozygotic twinning to occur is _________________twins. A late split, beyond day 8 postconception, will result in _______________twins. Because of the shared amniotic sac and this delayed division, monochorionic monoamniotic carries the additional risk of ______________.

Answer 65

monochorionic monoamniotic; monochorionic monoamniotic; conjoined twins

Question 66

monoamniotic, monochorionic twins that are attached at the head, thorax, abdomen, or lower body

Answer 66

conjoined twins

Question 67

___________, the most common form of twinning, arise from two separate fertilized ova.

Answer 67

Dizygotic twins

Question 68

Dizygotic twins are referred to as ________ twins because they have their own genetic structure and can differ from each other in many ways.

Answer 68

fraternal

Question 69

Dizygotic twinning always results in ___________ twins. That means, if there are _____ placentas, there must be ______ amnions. However, in early gestation, the placentas may fuse and appear as one large placenta with sonography.

Answer 69

dichorionic diamniotic; two; two

Question 70

twins that result from the fertilization of two separate ova and have dissimilar characteristics

Answer 70

fraternal twins

Question 71

an unfertilized egg

Answer 71

ovum

Question 72

the cell formed by the union of two gametes; the first stage of a fertilized ovum

Answer 72

zygote

Question 73

relates to the number of zygotes (fertilized ova)

Answer 73

zygosity

Question 74

_________ twins arise from a single zygote, whereas ________ twins form from two separate zygotes.

Answer 74

Monozygotic; dizygotic

Question 75

coming from one fertilized ovum or zygote

Answer 75

monozygotic

Question 76

two ova are fertilized by two sperms

Answer 76

dizygotic

Question 77

The fertilization of a single ovum that eventually divides, or the fertilization of several ova, can produce _______gestations. A fertilized egg is referred to as a ______. In multiple gestations, the term _________ refers to the number of eggs that are fertilized.

Answer 77

multiple; zygote; zygosity

Question 78

the outer membrane of a gestation that surrounds the amnion and developing embryo

Answer 78

chorion

Question 79

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

Answer 79

amnion

Question 80

Chorionicity, often referred to as placentation, relates to how many ________ are present.

Answer 80

placentas

Question 81

relates to the number of chorions and the type of placentation in a multiple gestation

Answer 81

Chorionicity

Question 82

________ refers to how many amnions or amniotic sacs are present. Twins who share the same amniotic sac are referred to as _______, whereas twins who have their own individual amniotic sac are _________.

Answer 82

Amnionicity; monoamniotic; diamniotic

Question 83

Patients with multiple gestations may present with the clinical indication of_________ and also an _______human chorionic gonadotropin blood level compared to a singleton pregnancy.

Answer 83

large for dates; elevated

Question 84

When compared with singleton pregnancies, twins have a four times higher risk of fetal _____ and a six times higher neonatal ____ rate.

Answer 84

mortality; morbidity

Question 85

the rate of actual deaths

Answer 85

mortality

Question 86

the relative frequency of occurrence of a disease; condition of suffering from that disease

Answer 86

morbidity

Question 87

A maternal ____of multiple gestations, assisted reproductive therapy (ART), ovulation _____ drugs, _____ maternal age, and maternal _____ have all been shown to increase the probability of multiple gestations

Answer 87

history; induction; advanced; obesity

Question 88

techniques used to treat infertility

Answer 88

assisted reproductive therapy (ART)

Question 89

a maternal age of 35 years or older

Answer 89

advanced maternal age

Question 90

coexisting ectopic and intrauterine pregnancies

Answer 90

heterotopic pregnancies.

Question 91

It has been reported that as many as 43% of triplets and higher order pregnancies are linked with _____. Thus, patients with a history of ovulation induction drugs or ART should be evaluated systematically, because they are more likely to have not only multiple gestations but also __________.

Answer 91

ART;heterotopic pregnancies

Question 92

Zygosity: ________ Description: Two separate fertilized ova Result: Dichorionic diamniotic Appearance: __________

Answer 92

Dizygotic; fraternal

Question 93

Zygosity: Monozygotic Description: One zygote splits between 4 and 8 d Result: _________ Appearance: Identical

Answer 93

Monochorionic diamniotic

Question 94

Zygosity: Monozygotic Description: One zygote splits before day 4 Result: _________ Appearance: Identical

Answer 94

Dichorionic diamniotic

Question 95

Zygosity: Monozygotic Description: One zygote splits late Result: _________ Appearance: Identical

Answer 95

Monochorionic monoamniotic

Question 96

All of the following complications are associated with multiple gestations except: a. preterm delivery b. high birth weight c. maternal anemia d. maternal preeclampsia

Answer 96

b. high birth weight

Question 97

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

Answer 97

a. twin embolization syndrome

Question 98

Twins having two placentas and one amniotic sac are referred to as: a. monochorionic diamniotic b. monoamniotic dichorionic d. dichorionic monoamniotic d. This does not occur

Answer 98

d. This does not occur