Twin Pregnancy

Question 1

Natural rate of twinning

Answer 1

1:90

Question 2

Incidence of dizygotic twins increases with….

Answer 2

Age
Parity
Weight 
Height
Higher in some families

Question 3

Multiple pregnancies is suspected in…

Answer 3

Large for date uterine size
Multiple foetal HRs detected
Multiple foetal parts felt
HCG and maternal serum alpha-fetoprotein is elevated for gestational age
Pregnancy with ART
]

Question 4

If multiple pregnancy is suspected, how is this confirmed?

Answer 4

USS

Question 5

What does ART mean?

Answer 5

Assisted reproduction technique

Question 6

Two types of twin zygosity

Answer 6

Monozygotic

Dizygotic

Question 7

What % of twins are dizygotic?

Answer 7

70-80%

Question 8

How do you get dizygotic twins?

Answer 8

Fertilisation of two ova

Question 9

What % of twins are monozygotic?

Answer 9

20-30%

Question 10

How do you get monozygotic twins?

Answer 10

Result from cleavage of a single fertilised ova

Question 11

In monozygotic twins, what determines placentation?

Answer 11

The timing of cleavage

Question 12

In dichorionic/diamniotic monozygotic twins, when did cleavage occur?

Answer 12

In the first 3 days after fertilisation

Question 13

What type of monozygotic twins has the lowest mortality rate of all the monozygotic twins?

Answer 13

Dichorionic/diamniotic

Question 14

What surrounds dichorionic/diamniotic monozygotic twins?

Answer 14

Each foetus will be surrounded by an amnion and chorion like dizygotic twins

Question 15

In monochorionic/diamniotic monozygotic twins, when did cleavage occur?

Answer 15

Between day 4 and 8 after fertilisation

Question 16

Mortality of monochorionic/diamniotic monozygotic twins

Answer 16

25%

Question 17

What covers a monochorionic/diamniotic monozygotic twin?

Answer 17

Share single placenta but separate amniotic sac

Question 18

“Chorionic” refers to…

Answer 18

Placenta

Question 19

“Amniotic” refers to….

Answer 19

Amniotic sac

Question 20

In monochorionic/monoamniotic monozygotic twins, when does cleavage occur?

Answer 20

After the 8th day of fertilisation (day 9-12)

Question 21

What causes a monochorionic/monoamniotic monozygotic twin?

Answer 21

Share single placenta and single sac

Question 22

How much of monozygotic twins are monochorionic/monoamniotic?

Answer 22

<1% of cases

Question 23

Mortality of monochorionic/monoamniotic monozygotic twins

Answer 23

mortality 50-60%, usually before 32 weeks

Question 24

For conjoined twins, when does cleavage occur?

Answer 24

After day 12

Question 25

Complications of multiple pregnancy

Answer 25

``` high perinatal mortality and morbidity (3-4x higher than singleton) abortion nausea and vomiting preterm labour (50%) IUGR PET (3x higher than singleton) polyhydramnios in 10% Congenital abnormalities PPH Placental abruption Placental praevia Discordant twin growth Malpresentation Cord prolapse Operative delivery ```

Question 26

At what gestation are twins delivered at?

Answer 26

37 weeks

Question 27

At what gestation are triplets delivered at?

Answer 27

33 weeks

Question 28

At what gestation are quadruplets delivered at?

Answer 28

29 weeks

Question 29

Causes of perinatal morbidity and morality in twins

Answer 29

``` Prematurity (RDS) Birth trauma Cerebral haemorrhage Birth asphyxia Stillbirth Congenital anomalies ```

Question 30

Definition of twin-twin transfusion (TTN)

Answer 30

One foetus (in monochorionic twins) donates blood to the other due to vascular anastomoses

Question 31

In twin twin transfusion, what happens to the recipient?

Answer 31

Heart failure Polyhydramnios Hydrops

Question 32

In twin-twin transfusion, what happens to the donor?

Answer 32

IUGR | Oligohydramnios

Question 33

Treatment of twin-twin transfusion

Answer 33

Amnio-reduction of recipient twin Intra-uterine blood transfusion to donor twin Selective foetal reduction Fetoscopic laser ablation of placenta anastomoses

Question 34

Antenatal management of multiple pregnancy

Answer 34

Adequate nutrition (300 calories per day per foetus) Prevent anaemia More frequent antenatal visits USS - chronicity at 9-10 weeks - nuchal translucency at 12-13+ weeks - assessment of foetal growth and wellbeing at 3-4 weeks from 23 weeks onwards Multifoetal reduction may be offered for high order multiple gestation in the first trimester Preterm labour risk - steroids for foetal lung maturation

Question 35

Preterm labour risk of multiple pregnancy is determined by....

Answer 35

Serial cervical length assessment

Question 36

When assessing chronicity, what sign is seen is dichorionic twins?

Answer 36

Twin peak sign (lambda)

Question 37

When assessing chorionicity, what sign is seen in monochorionic twins?

Answer 37

T sign

Question 38

Labour management in multiple pregnancy

Answer 38

If first foetus cephalic = normal delivery Non-vertex first twin = C section Locked twins with Breech-vertex = C section Active management of IIIrd stage to prevent PPH

Question 39

Management of labour in multiple pregnancy depends on....

Answer 39

Presentation Gestational age Presence of foetal complications Experience of obstetrician

Question 40

Usually how to deliver the twins if the first foetus is cephalic

Answer 40

Normal delivery

Question 41

How to deliver if the first twin is non-vertex

Answer 41

C section

Question 42

How to deliver if there are breech-vertex locked twins

Answer 42

C section