Multiple Pregnancy

Multiple Pregnancy
Incidence of multiple pregnancy

• Multiple gestation is increasingly common
• Over 3% of births in UHG are twins (Smith, K et al., 2010)
• Mainly due to assisted reproduction techniques & increased maternal age
• DZ more common in multiparous, family history & good nutritional status
• Increased risk of complications with twins

Zygosity

• Reflects the type of conception, one or two fertilized eggs
• 2/3 of twins dizygotic
• Fertilization of more than one egg
• Non identical or fraternal twins
• Genetically no more alike than siblings
• DCDA

Monozygotic Twins

• 1/3 of all twin pregnancies
• Splitting of one embryo after fertilization
• Chorionicity depends on when splitting occurs
• Identical and share similar genetic material