Multiple Pregnancy

Question 1

What is the incidence of multiple pregnancy?

Answer 1

• overall - twins 1-90 pregnancies
  - triplets 1-8100 pregnancies
• more common in women of African origin
• less common in Asian women
• recent OCP discontinuation
• assisted conception
• DZ twins more common in older mothers, increased parity, maternal family history

Question 2

What are dizygotic twins?

Answer 2

• non-identical
• each twin is a separate individual with its own placenta, amnion and chorion
• from two separate fertilized eggs
• fraternal twins (essentially just siblings)
• DCDA (dichorionic diamniotic)- fused or separate placenta

Question 3

What are monozygotic twins?

Answer 3

• identical
• occurs in roughly 1/3 of all pregnancies
• around 1% of these are conjoined
• connection between fetal circulations via the placenta
• same genes, blood group and physical features
• may be separated by chorion
• 3 kinds of MZ twins dependent on when divide occurs
• DCDA, DCMA, MCMA

Question 4

What are monchorionic monoamniotic MCMA?

Answer 4

• risks are conjoined risks
• arcadiac twin, twin reversal arterial perfusion syndrome
• TTTS - begins with renal system, ends with haemodynamic alteration
• IUGR - usually in 1 twin
• cord entanglement

Question 5

What are some of the maternal complications that may occur?

Answer 5

• exacerbation of minor disorders
• anaemia
• PIH
• APH

Question 6

What are some of the fetal problems that may occur?

Answer 6

• fetal malpresentation
• locked twins
• cord problems - prolapse, velamentous insertion, vasa praevia, entanglement
• preterm labour
• mode of delivery

Question 7

How would birth be managed?

Answer 7

• likely to labour early
• ?IOL
• if 1st twin cephalic vaginal birth encouraged
• CTG monitoring
• mobilisation encouraged
• may require epidural analgesia in case of manipulation of 2nd twin
• poor uterine action - consider oxytocics
• may be preterm