Multiple Pregnancies

Question 1

Incidence of Twin Pregnancy (per 1000 deliveries)

• …-… Far East
• …-… Europe
• …-… Nigeria

Answer 1

• 2-7 Far East
• 9-20 Europe
• 20-45 Nigeria

Question 2

Multiple Births - England & Wales

Answer 2

Question 3

Twinning rates - Netherlands

Answer 3

1978 - first IVF baby

Question 4

Triplets and higher order births E&W (per 1000 maternities)

Answer 4

• law limited no of embryos put back - avoid triplets if possible - explains the fall

Question 5

Aetiology of Multiple Pregnancy

• E…
• Increasing … …
• Increasing …
• … Hx
• … treatment
  
  • All factors for ‘super ovulation’

Answer 5

• Ethnicity
• Increasing Maternal Age
• Increasing Parity
• Family Hx
• Fertility treatment
  
  • All factors for ‘super ovulation’

Question 6

Multiple Pregnancy - Need to know…

• Zygosity - how many …
• Chorionicity - how many …
• Amnionicity - how many …

Answer 6

• Zygosity - how many eggs
• Chorionicity - how many placentas
• Amnionicity - how many amniotic saces

Question 7

Monozygous twin pregnancy - the twins are…

Answer 7

Monozygous twin pregnancy - the twins are identical (1 egg)

Question 8

Dizygous twin pregnancy - the twins are …

Answer 8

Dizygous twin pregnancy - the twins are non-identical (2 eggs)

Question 9

What proportion of twin pregnancies are monozygous?

Answer 9

1/3 (identical)

Question 10

What proportion of twin pregnancies are dizygous?

Answer 10

2/3 (non-identical)

Question 11

Early Primordia - 14 days

Answer 11

Question 12

Folding of the embryo in Week 4

Answer 12

Question 13

The Endometrium and Fetal Membranes

Answer 13

Question 14

Dizygotic twins

• How many eggs?
• Identical/Non-identical Twins?
• Accounts for … of all twin pregnancies

Answer 14

• How many eggs? - 2
• Accounts for 2/3 of all twins
• non-identical

Question 15

Monozygotic Twins

• How many eggs?
• Identical/Non-identical Twins?
• Accounts for … of all twin pregnancies

Answer 15

• 1 egg
• Identical
• 1/3

Question 16

Monozygotic Twins - 3 Different Outcomes

• DCDA / MCDA / MCMA

Answer 16

• Splitting at 2 cell stage: DCDA (seperate chorions, amnions and placentae)
• OR
• Splitting in early blastocyst yields 2 inner cell masses but common chorion, seperate amnions and joined placentae MCDA
• OR
• Later splitting yields 2 embryos from one inner cell mass - common chorion, amnion and ‘joined’ placentae MCMA

Question 17

What is a dichorionic diamniotic (DCDA) twin pregnancy?

Answer 17

a type of twin pregnancy where each twin has its own chorionic and amniotic sacs (can be as a result of dizygotic twin or monzygotic twin)

• So, DCDA twins can be identical or non-identical

Question 18

What are monochorionic, diamniotic twins?

Answer 18

Monochorionic, diamniotic (MCDA) twins are the product of a single fertilized ovum (egg), resulting in genetically identical offspring. MCDA twins share a single placenta (blood supply) but have separate amniotic sacs.

Question 19

What is a monochorionic monoamniotic (MCMA) twin pregnancy?

Answer 19

This rare type of identical twins not only share a placenta, but also share the same amniotic sac (pocket of fluid).

Question 20

Twin pregnancy - Dichorionic

Answer 20

• All dizygous twins are dichorionic
• Dichorionic twins must be diamniotic
• Dichorionic = separate circulations
• 1:3 monozygous twins are dichorionic

Question 21

Twin pregnancy - Monochorionic

Answer 21

• Monozygous twins may be monochorionic (2/3) or dichorionic
• MC have vascularly joined placentae
• MC twins 3x increased loss rate
• MC twins usually diamniotic

Question 22

Diagnosis of Twin Pregnancy

• Size of …
• By … scan
• Up to …% at delivery worldwide

Answer 22

• Uterine size
• Ultrasound scan
• Up to 50% at delivery worldwide

Question 23

What type of pregnancy?

Answer 23

dichorionic pregnancy

Question 24

What type of pregnancy?

Answer 24

monochorionic diamniotic - only one chorion

Question 25

What type of pregnancy?

Answer 25

rare - MCMA (monochorionic monoamniotic)

Question 26

_Multiple pregnancy - Complications_

Answer 26

* “Everything except post-dates” * Symptoms of pregnancy * Anaemia * Hypertension * Intrauterine growth restriction * Pre-term labour * Delivery problems * Perinatal mortality

Question 27

_Twin pregnancy - Mortality_ * Stillbirth – defined as after .... weeks * Early neonatal – first ... days * Neonatal – in first ... days * Perinatal mortality – ... risk + early ... risk * Infant – first ... * Rates shown are per 1000 births

Answer 27

* Stillbirth – after **24** weeks * Early neonatal – first **7** days * Neonatal – in first **28** days * Perinatal mortality – **SB** risk + early **neonatal** risk * Infant – **first** year * Rates are per 1000 births * Twins and triplets - higher risk as shown

Question 28

_Twin pregnancy - First trimester management_ * Discuss ... for ... anomalies * Determine ... * Discuss ... ... if triplets or more

Answer 28

* Discuss **screening** for **chromosomal** anomalies * Determine **chorionicity** * Discuss **fetal** **reduction** if triplets or more

Question 29

_Twin pregnancy - Second trimester management_ * Detection of fetal ... * Serial scans for growth for all * – DC monthly from ... weeks * Serial scans for TTTS (Transfusion syndrome) if ... twins * 2 weekly 16-28 weeks then monthly * Maternal ...

Answer 29

* Detection of fetal **abnormality** * Serial scans for growth for all * –DC monthly from **24** weeks * Serial scans for TTTS if **MC** twins * 2 weekly 16-28 weeks then monthly * Maternal **complications**

Question 30

_Twin pregnancy - Monochorionic twins_ * More fetal ... * More fetal ... restriction * Twin to twin ...

Answer 30

* More fetal **malformation** * More fetal **growth** restriction * Twin to twin **transfusion**

Question 31

What is Twin-to-twin transfusion syndrome (TTTS) ?

Answer 31

Twin-to-twin transfusion syndrome (TTTS) is a rare pregnancy condition affecting identical twins or other multiples. TTTS occurs in pregnancies where twins share one placenta (afterbirth) and a network of blood vessels that supply oxygen and nutrients essential for development in the womb. (MC twins, second trimester risk)

Question 32

_Monochorionic twin pregnancy - Twin to twin transfusion_ * Unbalanced placental vascular a... * Donor twin is ..., decreased liquor * High ... (esp recipient) * Rx - laser or amnio-reduction * Early delivery by ...

Answer 32

* Unbalanced placental vascular **anastamoses** * Donor **smaller**, decreased liquor * High **mortality** (esp recipient) * Rx - laser or amnio-reduction * Early delivery by **caesarean**

Question 33

_Twin pregnancy - Third trimester management_ * Scanning as in ... trimester * Monitor ... ... * ...-... labour * ... planning

Answer 33

* Scanning as in **2nd** trimester * Monitor **blood pressure** * **Pre**-**term** labour * **Delivery** planning

Question 34

_Twin pregnancy - Delivery planning_ * 37-38 weeks for ... twins * –vaginal birth or caesarean * Presentation of twin I * 36-37 weeks for ... twins * ?all ... twins by caesarean? * Pregnancy complications

Answer 34

* 37-38 weeks for **DC** twins * – can be via vaginal birth or caesarean * Presentation of twin I * 36-37 weeks for **MC** twins * ?all MC twins by caesarean? * Pregnancy complications

Question 35

_Twin pregnancy - Labour management_ * Monitoring ... twins * Problems delivering twin ... * Risk of ... bleed

Answer 35

* Monitoring **both** twins * Problems delivering twin **II** * Risk of **postpartum** bleed

Question 36

_Twin pregnancy - Puerperium_ * ... difficulties * ... & ... support

Answer 36

* **Feeding** difficulties * **Emotional** & **social** support

Question 37

Puerperium is ...

Answer 37

the period of about six weeks after childbirth during which the mother's reproductive organs return to their original non-pregnant condition

Question 38

_Multiple pregnancy - Higher order multiples_ * Consider fetal ... * Determine ... * High risk of ... labour * Deliver preterm by ... * Postpartum ... * Difficult ... & after

Answer 38

* Consider fetal **reduction** * Determine **chorionicity** * High risk of **preterm** labour * Deliver preterm by **caesarean** * Postpartum **haemorrhage** * Difficult **puerperium** & after