Multiple gestations/complications registry review

Question 1

Complications associated with multiple gestations

Answer 1

-Increased risk of preeclampsia
-Preterm delivery
-Low birth weight
-Fetal anomalies
-Miscarriage
-Perinatal death

Question 2

Twinning

Answer 2

Either arise from 2 separate eggs that were fertilized or 1 zygote that splits

Question 2

Median gestational age for delivery of twins

Answer 2

36 weeks
Multiple gestations greater than twins are most likely the result of assisted reproduction and have increased risk of complications

Question 3

Dizygotic

Answer 3

2 separate eggs are fertilized
-Fraternal since they come from separate ovum
-Dichorionic/diamniotic ALWAYS
-2 GS, 2 placenta, 2YS, 2 amnion
*MOST common

Question 4

Monozygotic

Answer 4

1 ovum that splits
-Identical
*EARLIER split = more divided they will be
-Dichorionic/diamniotic (<4days)
-Monochorionic/diamniotic (4-8days)
-Monochorionic/monoamniotic (>8days)

Question 5

Chorionicity

Answer 5

Chorion forms the gestational sac and placenta

Question 6

Dichorionic

Answer 6

Two of each, gestational sac and placenta

Question 7

Monochorionic

Answer 7

One gestational sac and placenta

Question 8

Amnionicity

Answer 8

Amnion is the inner membrane and goes with yolk sac

Question 9

Diamniotic

Answer 9

A membrane between and 2 yolk sacs

Question 10

Monoamniotic

Answer 10

One membrane and one yolk sac

Question 11

Dichorionic/diamniotic

Answer 11

-Early division (<4days)
-2GS, 2 placenta, 2 amnion, 2YS

Question 12

Monochorionic/diamniotic

Answer 12

-4-8days
-1GS, 1 chorion, 1 placenta, 2 amnions, 2 YS
-Thin membrane inserting like a [T] into placenta which means one shared placenta
*MOST common division

Question 13

Monochorionic/monoamniotic

Answer 13

-Late division (>8days)
-Everything shared
-1GS, 1 chorion, 1 placenta, 1 amnion, 1 YS

Question 14

1st trimester determination of twin type

Answer 14

-Dichorionic seen as two completely separate GS within uterine cavity (must also be diamniotic)
-Monochorionic appears as 1 GS, count the amnions or YS to determine amnionicity

Question 15

2nd trimester determination of twin type

Answer 15

-Dichorionic is more obvious if 2 separate placentas are identified
*Look for twin peak sign (2 placentas may appear as 1 fused placenta)

Question 16

Twin complications (monochorionic twins ONLY)

Answer 16

Monochorionic share one placenta therefore increased risk of fetal shunting and growth issues

Question 17

Twin to twin transfusion syndrome (TTTS)

Answer 17

Fetal shunting through vessels in the placenta, donor to recipient

Question 18

Donor twin in TTTS

Answer 18

Gives blood to other, eventually suffers from IUGR
-IUGR
-Oligohydramnios
-Anemia

Question 19

Recipient twin with TTTS

Answer 19

Receives too much blood and can suffer from hydrops and CHF due to the overload of blood going to the heart
-Larger
-Polyhydramnios
-Hydrops/CHF

Question 20

1st initial sonographic indication of TTTS

Answer 20

Discordant fetal growth

Question 21

Stuck twin

Answer 21

Most severe TTTS. Oligohydramnios is so severe that the donor twin appears to be stuck to the side of the uterine wall
-Determine donor by size or sac difference

Question 22

Twin reversed arterial perfusion
(TRAP)

Answer 22

Abnormal anastomoses of placental vessels that support the growth of parasitic or acardiac twin
-1 normal fetus, 1 abnormally developed with NO heart

Question 23

Pump twin

Answer 23

Living twin in TRAP twins, maintains the growth of the parasitic twin
-Mortality rate 50% secondary to polyhydramnios and prematurity

Question 24

Acardiac twin

Answer 24

Abnormally developed twin in TRAP twins, no heart
-Absent upper body
-Absent heart
-Hydrops

Question 25

Conjoined twins

Answer 25

Occurs in ONLY monochorionic/monoamniotic twins when zygote splits > 13 days
-Multiple forms
-40% chance stillborn

Question 26

Thoracopagus conjoined twins

Answer 26

Twins fused at the chest
*MOST common

Question 27

Omphalopagus conjoined twins

Answer 27

Twins fused at the chest

Question 28

Twin demise

Answer 28

When one or more embryos or twins die in utero
*Dichorionic twins have a greater chance of survival in case of twin demise (especially early 1st trimester)

Question 29

Fetus papyraceus

Answer 29

Fetal death in 1st trimester and is maintained, not resorbed. May eventually become vanishing

Question 30

Vanishing twin

Answer 30

Death of a twin in the early 1st trimester and is reabsorbed

Question 31

Monochorionic fetal demise

Answer 31

One demise will often lead to the demise of the other

Question 32

Twin embolization syndrome

Answer 32

Demised twin begins to breakdown and vascular products can travel through common vascular channels with shared placenta
-CNS and kidneys are usually affected
-Possible with monochorionic fetal demise in 2nd trimester