Multiple pregnancies

Question 1

Define Dizygotic

Answer 1

Two different oocytes fertilised by two different sperm

Embryo can be different sex and are NOT identical

Question 2

Define Monozygotic

Answer 2

when one sperm fertilise one egg and the embryo decides into 2

Can share the same placenta and amnion depending on time of separation

Question 3

Define monochorionic

Answer 3

When twins share the same placenta

Question 4

Define Dichorionic

Answer 4

When twins have 2 separate placentas

Question 5

Define Monoamniotic

Answer 5

When twins share the same amniotic membrane

Question 6

Define Diamniotic

Answer 6

When twins have 2 separate amniotic membranes

Question 7

Describe dizygotic twins in terms of amniotic and chorionic composition

Answer 7

Diamniotic Dichorionic - DCDA

Question 8

When does the embryo split to produce Dichorionic Diamniotic twins

Answer 8

Before Day 3 - before implantation

Question 9

When does the embryo split to produce Monochorionic Diamniotic

Answer 9

Between days 4-8 - after implantation

Question 10

When does the embryo split to produce Monochorionic Monoamniotic

Answer 10

Between days 9-13 - after implantation

Question 11

What happens when there is incomplete division of an embryo?

Answer 11

Conjoined twins

Question 12

List 4 symptoms associated with multiple pregnancy

Answer 12

1. Hyperemesis gravidum
2. Uterus large for dates
3. 3+ foetal poles palpable >24 weeks
4. Multiple foetal hearts heard on auscultation

Question 13

How are multiple pregnancies diagnosed?

Answer 13

US scan during the first trimester (GS)

Question 14

How is Dichorionicity diagnosed on US? Which sign do we see?

Answer 14

1. Two separate placentas seen
2. Lamda sign seen <14 weeks
3. Different sex babies

Question 15

What maternal complications are associated with multiple pregnancies? (6)

Answer 15

1. Pre-eclampsia (5x)
2. Gestational diabetes
3. PPH/APH
4. Anaemia
5. operative delivery
6. Placenta privea

Question 16

Which type of twins has a higher foetal risk?

Answer 16

Monochorionic twins

Question 17

What are the foetal complications associated with multiple pregnancies?

Answer 17

1. Miscarriage
2. Congenital abnormalities
3. IUGR
4. Pre-term labour - increased risk of death
5. increased risk of death - intranatally and postnatally
6. Disability

Question 18

What problems can you get with MC twins?

Answer 18

1. Twin to twin transfusion syndrome
2. Twin reversed arterial perfusion (TRAP)
3. IUGR

Question 19

What is Twin to twin transfusion syndrome?

Answer 19

Occurs due to vascular anastomosis in the shared placenta where one twin takes up all the blood supply (recipient) from the other twin (Donor twin)

Question 20

What happens to the Donor twin in TTTS

Answer 20

Fluid depleted

IUGR

oligohydraminous

Question 21

What happens to the Recipient twin in TTTS

Answer 21

Fluid overload

Polycythemia

Cardia faliure

Death

Question 22

What treatment options are there for TTTS?

Answer 22

1. Laser ablation of the placental anastomosis - lowest risk of handicap
2. selective foeticide by cord occlusion

Question 23

What is twin reversed arterial perfusion?

Answer 23

One twin is genetically abnormal (No/non functioning heart) therefore receives blood from the other twin and the umbilical artery blood supply is reversed.

Pumper twin has a high risk of developing cardiac failure

Question 24

What is the risk on a twin if the other one dies in a dichorionic pregnancy?

Answer 24

In the first trimester: No effect

In the second/third: precipitates labour

Question 25

What is the risk on a twin if the other one dies in a Monochorionic pregnancy?

Answer 25

Subsequent death or neurological damage due to hypovolemia occurs (shared circulation)

Question 26

What are the intrapartum risks associated with multiple pregnancies? (5)

Answer 26

1. Malpresentation 2. Foetal hypoxia in second twin after first one is delivered 3. Cord prolapse 4. Operative delivery 5. PPH

Question 27

What do you need to do in the antepartum period in any twin pregnancy?

Answer 27

1. Consultant led care 2. Iron, folic acid and aspirin 3. Early US to determine type

Question 28

At what weeks do you need to do serial scans for twins?

Answer 28

28, 32 and 36

Question 29

When is it recommended to deliver DCDA twins?

Answer 29

37 weeks

Question 30

When is it recommended to deliver MC twins?

Answer 30

36 weeks

Question 31

When is CS indicated?

Answer 31

1. Breech or transverse lie | 2. All monochorionic twins

Question 32

How are twins vaginally delivered?

Answer 32

1. In theatre usually to allow speedy surgical intervention 2. First twin delivered normally 3. EXTRA CTG monitoring for second twin. 4. Recommended to monitor first twin VIA head and second twin via abdomen 5. SCAN/feel for the presentation of the second twin after the first one is delivered 6. Consider CS/breech extraction if second baby is in a weird position 7. Give oxytocin if the contractions are reduced after the delivery of the first twin

Question 33

Is TVS measurement of cervical length advised in preterm labour of twins?

Answer 33

NO

Question 34

Can progesterone prevent preterm twin labour?

Answer 34

NO

Question 35

What are the complications of laster ablation/coagulation in TTTS? (4)

Answer 35

1. Rupture of membranes 2. Infection 3. Pre-term delivery 4. Miscarriage

Question 36

When is selective reduction advised for multiple pregnancies?

Answer 36

12 weeks

Question 37

How do we terminate DC twins?

Answer 37

KCL injection before 14 weeks of gestation

Question 38

How do we terminate MC twins?

Answer 38

Umbilical cord occlusion using diathermy

Question 39

What increases the risk of having multiple pregnancies? (4)

Answer 39

1. Assisted conception 2. Genetics 3. Increased maternal age 4. IVF