Module 13: Multiple Gestation Complications Flashcards Preview

OB/GYN 303 > Module 13: Multiple Gestation Complications > Flashcards

Flashcards in Module 13: Multiple Gestation Complications Deck (38)
Loading flashcards...
1
Q

Describe the twinning stats:

A

1% of all pregnancies

70% dizygotic and 30% monozygotic

2
Q

What increases the frequency of dizygotic twins? (4)

A
  • Maternal age (very young and >37) and parity (++)
  • Hereditary
  • Racial background
  • Pharmaceutical agents/ART programs
3
Q

How does monozygotic twinning happen?

A

A single fertilized ovum replicates during the early development

4
Q

What is the most important predictor of pregnancy outcome in twins?

A

Number of placentas

5
Q

What is chorionicty and when is it best determined?

A

The number of placentas

Between 10 to 14 weeks LMP

6
Q

What does lambda (twin peak sign) represent?

A

Dichorionic twinning (two placentas)

7
Q

What does the T sign represent?

A

Monochorionic twinning (one placenta)

8
Q

Only one placenta forms in what circumstance?

A

If the division occurs after implantation

9
Q

Can dichorionic-diamniotic occur with monozygotic twins?

A

Yes (morula splits before it implants and each implants separately)

10
Q

When does division occur with mono-di twinning?

A

At the blastocyst stage, day 4-8 post fertilization

11
Q

When does division occur with mono-mono twinning?

A

At the embryonic disc stage, after the amniotic sac has formed day 8-12 post fertilization

12
Q

When does division occur with conjoined twins?

A

Incomplete division occurs at the embryonic disc stage after day 13 post fertilization

13
Q

What are two examples of abnormal twinning variations?

A

Conjoined twins and TRAP syndrome

14
Q

Where are conjoined twins most commonly joined at?

A

Chest or abdomen 70% of the time (thoracopagus or omphalopagus)

15
Q

What does TRAP syndrome stand for?

A

Twin reversed arterial perfusion

16
Q

TRAP syndrome occurs with what type of twinning exclusively?

A

Monochorionic

17
Q

What is TRAP syndrome?

A

A normal baby develops along with a deformed baby (only lower trunk) that steals the blood supply due to arterial-arterial or venous venous shunts in the placenta.

18
Q

Why is the donor (normal) twin in TRAP syndrome at high risk for developing hydrops?

A

Due to high cardiac output resulting in cardiac failure

19
Q

What are 5 twin complications?

A
  • Twin to twin transfusion syndrome
  • Twin embolization syndrome
  • Premature delivery
  • Congenital anomalies
  • Cord accidents
20
Q

Twin to twin transfusion syndrome occurs in what type of twinning?

A

Monochorionic

21
Q

What is twin to twin transfusion syndrome?

A

Arteriovenous fistulas in the placenta(A-A, V-V or A-V), the donor becomes anemic and the recipient becomes fluid overloaded resulting in twins differing in size > 20%

22
Q

Explain the recipient appearance in twin to twin transfusion syndrome:

A

Large, hypertensive, polyhydramnios, edematous

23
Q

Explain the donor appearance in twin to twin transfusion syndrome:

A

Small, hypotensive, oligohydramnios, stuck twin appearance

24
Q

What is a stuck twin?

A

In TTTS the donor twin may have little/no fluid

25
Q

When does twin embolization syndrome occur?

A

Occurs when there is a demise of one twin clots can pass from the demise to the surviving twin resulting in infarcts in the liver and brain

26
Q

What will cause asphyxia in the live surviving twin in twin embolization syndrome?

A

Demised twins placenta becomes a low pressure bed allowing blood to pool in the placenta (no blood pumping out due to demised fetus)

27
Q

What does a papyraceous fetus mean?

A

Demised fetus

28
Q

There is a increased risk of cord accidents in what kind of twinning?

A

Mono-mono

29
Q

What country has a higher than average dizygotic twin rate?

A

Nigerian

30
Q

How does dizygotic twinning happen?

A

Fertilization of two separate ova

31
Q

What are the types of dizygotic twinning?

A
  1. DC/DA

2. DC/DA fused

32
Q

What are the types of monozygotic twinning?

A
  1. DC/DA
  2. DC/DA fused
  3. MC/DA
  4. MC/MA
  5. Conjoined
33
Q

How do you label twin A?

A

Label the presenting twin as A and label which maternal side the twin is on

34
Q

What are other names for TRAP syndrome?

A

Acardiac parabolic twin or acardiac monster

35
Q

What is fetus in fetu?

A

A parasitic twin resembling a teratoma within the abdomen of it’s sibling

36
Q

What is superfetation?

A

Fertilization of two separate ova months apart

37
Q

Is a stuck twin indicative of monochorionic twins?

A

No because a stuck twin may also occur in dichorionic twins with placenta insufficiency (IUGR)

38
Q

What is the US appearance of twin embolization syndrome? (4)

A
  • Ventriculomegaly
  • Porencephalic cysts
  • Cerebral atrophy
  • Microcephaly