Last reviewed 04/2022

  • incidence of multiple births has risen in the last 30 years

    • in 2009, 16 women per 1000 giving birth in England and Wales had multiple births compared with 10 per 1000 in 1980

    • rising multiple birth rate is due mainly to increasing use of assisted reproduction techniques, including in vitro fertilisation (IVF)
      • up to 24% of successful IVF procedures result in multiple pregnancies

    • multiple births currently account for 3% of live births

    • multiple pregnancy is associated with higher risks for the mother and babies

      • women with multiple pregnancies have an increased risk of miscarriage, anaemia, hypertensive disorders, haemorrhage, operative delivery and postnatal illness

      • maternal mortality associated with multiple births is 2.5 times that for singleton births

      • overall stillbirth rate in multiple pregnancies is higher than in singleton pregnancies: in 2009 the stillbirth rate was 12.3 per 1,000 twin births and 31.1 per 1,000 triplet and higher-order multiple births, compared with 5 per 1,000 singleton births

      • risk of preterm birth is also considerably higher in multiple pregnancies than in singleton pregnancies, occurring in 50% of twin pregnancies (10% of twin births take place before 32 weeks of gestation)

      • feto-fetal transfusion syndrome, most commonly occurring in twin pregnancies (where it is termed twin-to-twin transfusion syndrome), is a condition associated with a shared placenta and accounts for about 20% of stillbirths in multiple pregnancies

      • additional risks to the babies include intrauterine growth restriction and congenital abnormalities
        • in multiple pregnancies, 66% of unexplained stillbirths are associated with a birthweight of less than the tenth centile, compared with 39% for singleton births
        • major congenital abnormalities are 4.9% more common in multiple pregnancies than in singleton pregnancies