Multifetal Gestation and Malpresentation (Moulton)

Question 1

__1__ arise when two separate ova are fertilized by two separate sperm.

Each will have its own __2__, __2__, and __2__.

Answer 1

1) Dizygotic twins (Fraternal)

2) Amnion, chorion and placenta

Question 2

__1__ arise from the cleavage of a single fertilized ovum at various stages during embryogenesis.

Thus the arrangement of __2__ and __2__ will depend on the time at which the embryo divides.

Answer 2

1) Monozygotic Twinning (Identical)

2) Fetal membranes and placentas

Question 3

With Monozygotic twins, if cleavage takes place from 0-3 days, what happens with placentation? (30% of monozygotic twins have this placentation)

Answer 3

1) 2 chorions
2) 2 amnions
3) Placentas can be separate or fused

Question 4

With Monozygotic twins, if cleavage takes place from 4-8 days, what happens with placentation? (69% of monozygotic twins have this placentation)

Answer 4

1) 1 chorion

2) 2 amnions

Question 5

With Monozygotic twins, if cleavage takes place from 9-12 days, what happens with placentation? (1% of monozygotic twins have this placentation)

Answer 5

1) 1 chorion

2) 1 amnion

Question 6

Monochorionic monoamniotic placentation (9-12 days) is the most dangerous because there are no separating amnions, this causes what risk to be high?

Answer 6

Cord entanglement is high

Question 7

With Monozygotic twins, if cleavage takes place from 13-15 days, what happens with placentation?

This causes conjoined twins and if they are craniopagus (2% incidence) this means?

If they are thoracopagus (30-40% incidence)?

If they are ischiopagus (6% incidence)?

Answer 7

1) 1 chorion and 1 amnion
2) Joined at the cranium
3) Joined at the chest wall
4) Joined by the coccyx and sacrum

Question 8

Dizygotic twins is strongly influenced by?

It is twice as common after?

Answer 8

1) Maternal age

2) 35 y/o

Question 9

You should suspect multiple gestations if ___ is higher than normal.

Answer 9

hCG

Question 10

Which type of twins have an increased incidence of congenital anomalies, weight discordance, premature delivery, and fetal demise?

Answer 10

Monozygotic

Question 11

When using US when determining zygosity for dizygotic twins you might see a different __1__ amongst the twins.

There may be visualization of a __2__ septum.

A __3__ sign at the base of septum may be seen.

Answer 11

1) Fetal gender
2) Thick amnion-chorion septum
3) Peak or inverted V

Question 12

When using US when determining zygosity for monozygotic twins what may be seen?

Answer 12

Dividing membrane is thin

Question 13

If ultrasound is not definitive in determining zygosity, what should you do?

Answer 13

1) Inspect placenta after delivery

2) DNA analysis

Question 14

Conjoined twins results do to cleavage occurring at?

Answer 14

13-15 days

Question 15

With conjoined twins elective termination is an option if what is identified?

Answer 15

Cardiac or cerebral fusion

Question 16

What has a 90% chance of occurring in monochorionic twins?

The most common type is?

Answer 16

1) Interplacental vascular anastomoses

2) Arterial-arterial

Question 17

With interplacental vascular anastomoses, vascular communications between the 2 fetuses through the placenta can cause several problems such as?

Answer 17

1) Abortion
2) Polyhydramnios
3) Twin-twin transfusion syndrome (TTTS)

Question 18

Twin-twin transfusion syndrome results secondary to uncompensated __1__ anastomoses in a monochorionic placenta.

This leads to a net transfer of blood flow going from one twin to the other. Hypovolemia, hypotension, anemia, oligohydramnios, growth restriction occurs to the __2__.

Hypervolemia, polyhydramnios, thrombosis, hypertension, polycythemia, edema, cardiomegaly, and congestive heart failure occurs to the __3__.

Answer 18

1) Arteriovenous
2) Donor twin
3) Recipient twin

Question 19

With Twin-twin transfusion syndrome both twins are at risk of demise because of?

Answer 19

Heart failure

Question 20

What findings on US for TTTS are seen with the donor twin?

For the recipient twin?

Answer 20

1) Smaller, stuck appearance, oligohydramnios

2) Larger, polyhydramnios, ascites

Question 21

TTTS treatment consists of ____ of the anastomosis vessels on the placenta at specialized centers.

Answer 21

Laser photocoagulation

Question 22

Arterial to arterial anastomoses may lead to reversed blood flow causing __1__ within critical organs or atresias due to trophoblastic embolization.

The recipient twin, being perfused in a reverse direction with poorly oxygenated blood fails to develop normally. It is known as an __2__ twin.

This twin presents with fully formed __3__ but no anatomic structures above the __4__.

Answer 22

1) Thrombosis
2) Acardiac twin
3) Lower extremities
4) Abdomen

Question 23

What umbilical cord abnormalities can be seen primarily with monochorionic twins?

Answer 23

1) Absence of umbilical artery
2) Velamentous umbilical cord insertions (insertion of the cord into the membranes rather than directly into the placenta)

Question 24

The incidence of single fetal death in monozygotic twins in utero is up to 5% and if gestation is 20 weeks or greater __1__ can develop.

If gestation is < 12 weeks the dead fetus is __2__.

If > 12 weeks, the fetus shrinks, dehydrates and flattens called __3__.

Answer 24

1) Retained dead fetus syndrome
2) Reabsorbed (Vanishing twin syndrome)
3) Fetus papyraceus

Question 25

Retained dead fetus syndrome can lead to __1__ in the mother.

You want to check __2__ and __2__ levels weekly.

Answer 25

1) Disseminated intravascular coagulopathy

2) Platelets and fibrinogen

Question 26

With the high risk of ____ and ____ close antepartum surveillance is required.

Answer 26

Preterm birth and preeclampsia

Question 27

In the third trimester, cervical length of less than ____ at 24-28 weeks doubled the risk for premature births in twins.

Answer 27

25mm

Question 28

Monoamniotic twins should be delivered at __1__ weeks.

This is secondary to an increase risk for __2__.

Delivering is recommended at __3__ weeks for twins if pregnancy has no complications.

Answer 28

1) 32
2) Lethal cord entanglement
3) 38

Question 29

What presentation occurs 40-50% of the time for twins?

Answer 29

Vertex-vertex

Question 30

Which twin is at increased risk of cord prolapse, placental abruption and malpresentation?

Answer 30

Second twin

Question 31

With delivery of twins be prepared for postpartum hemorrhage secondary to?

Answer 31

Uterine atony

Question 32

__1__ and __1__ presentations can be delivered vaginally but often are delivered by cesarean section.

__2__ and __2__ twins are delivered via cesarean section.

Answer 32

1) Vertex-transverse and vertex-breech

2) Breech-breech and breech-vertex

Question 33

What can occur secondary to prematurity and congenital anomalies?

Answer 33

1) Respiratory distress syndrome (RDS)
2) Intracranial hemorrhage
3) Birth asphyxia

Question 34

Prematurity increases as the number of fetus increase, the average gestation at delivery for Triplets is ___ weeks.

The average gestational age at delivery for Quadruplets is ___ weeks.

Answer 34

1) 33

2) 29

Question 35

Malpresentation refers to any fetal presentation other then __1__.

__2__ is the most common malpresentation.

Answer 35

1) Vertex

2) Breech

Question 36

Breech presentation occurs when the fetal ____ or ____ presents into the maternal pelvis.

Answer 36

Buttocks or lower extremities

Question 37

What is the most common factor associated with breech?

Answer 37

Prematurity

Question 38

Which type of breech presentation is the most common where the thighs are flexed and the lower extremities are extended at the knees?

Which type of breech presentation is where the thighs and the lower extremities are flexed?

Which type of breech presentation is where one or both thighs are extended and one or both feet are below the buttocks?

Answer 38

1) Frank
2) Complete
3) Incomplete

Question 39

____ involves applying pressure to the mother’s abdomen to turn the fetus in either a forward or backward somersault to achieve a vertex presentation.

Answer 39

External cephalic version

Question 40

In order for vaginal delivery of breech presentation, the fetus must be in a ____ or ____ breech presentation.

Answer 40

Frank or complete

Question 41

The standard of care now in most practices is to deliver all breeches by?

Answer 41

Cesarean section

Question 42

When undergoing assisted breech vaginal delivery, a __1__ wrapped around the baby can be used for better traction.

You want to maintain cephalic flexion by applying pressure on fetal __2__, NOT fetal __3__.

__4__ is a tool that can be used in breech deliveries.

Answer 42

1) Towel
2) Maxilla
3) Mandible
4) Piper

Question 43

__1__ presentation occurs when the presenting part of the fetus is between the facial orbits and anterior fontanelle.

The presenting diameter is the __2__ diameter.

__3__ bones are the point of designation.

Answer 43

1) Brow
2) Supraoccipitomental
3) Frontal

Question 44

50-75% of brow presentation will convert to a face presentation through __1__ or a vertex presentation through __2__ and then deliver.

Answer 44

1) Extension

2) Flexion

Question 45

The vertex presentation allows the ____ diameter to be the presenting diameter.

Answer 45

Suboccipitobregmatic

Question 46

__1__ presentation is characterized by full extension of the fetal head and neck with occiput against upper back.

It can be seen frequently with fetal malformation such as __2__.

The fetal __3__ is chosen as point of designation.

Answer 46

1) Face
2) Anencephaly
3) Chin

Question 47

The mentum must be __1__ in order to deliver a face presentation vaginally.

You can NOT deliver face presentation vaginally if the mentum is __2__. Will need to proceed with cesarean section.

Answer 47

1) Anterior

2) Posterior

Question 48

The face presentation allows the ____ diameter to be the presenting diameter.

Answer 48

Trachelobregmatic

Question 49

____ presentation is defined when a fetal extremity (usually the hand) is found prolapsed alongside the presenting fetal part (head).

Answer 49

Compound