Many people think that stillbirths happen because of a developmental or genetic problem that means the baby could not survive. In fact, fewer than one in ten stillbirths is caused by what’s known as a ‘major congenital abnormality’. In a large number of stillbirths, the baby appears to be completely healthy.

Sometimes the mother has a condition that affects the pregnancy and sometimes there are major problems with the placenta or the umbilical cord.

For around one-third of babies, there is no clear cause for the death. For another third of stillbirths the baby was apparently healthy but was smaller than would be expected. In both cases, these stillbirths may be described as ‘unexplained’.

Placental problems

Researchers believe that some ‘unexplained’ stillbirths happen because the placenta, which joins the woman’s and baby’s blood systems, starts working less well. The deterioration may happen gradually, and may not be picked up by current routine antenatal monitoring.

It may mean the baby doesn’t grow as well as it should because the blood and oxygen supply is compromised in some way, Around a third of stillborn babies have not reached their growth potential and poor growth or growth that starts well and tails off during pregnancy, is a sign that a baby is at risk of stillbirth.  If this is the case, the baby may also start to move less often.

Sands is funding research that asks whether encouraging women to be aware of their baby’s movements and to tell their midwife promptly if their baby is not moving as it normally does could help reduce the number of stillbirths. You can read more about this research study, called AFFIRM, here.

If you are pregnant and are concerned about your baby’s movements please contact your midwife.

We are also funding research looking at scanning in third trimester, which is aimed at improving methods for identifying babies who are not growing as they should.

Other conditions

Stillbirth may also happen because of:

  • bleeding (haemorrhage) before or during labour
  • placenta abruption, which is when the placenta separates from the womb before the baby is born
  • pre-eclampsia, which causes high blood pressure in the mother
  • the umbilical cord slipping down through the entrance of the womb before the baby is born (known as cord prolapse) or wrapping around the baby’s neck
  • intrahepatic cholestasis of pregnancy (ICP) or obstetric cholestasis, a liver disorder
  • a genetic problem
  • gestational diabetes, which is a type of diabetes that develops during pregnancy
  • infection (for a list of infections which cause stillbirth visit NHS Choices).

If you are pregnant please read our advice for a safer pregnancy.

Post mortems

Parents of a stillborn baby will be asked whether they want their baby to have a post mortem. A post mortem can sometimes find the cause of the stillbirth; it can also help rule out some causes. This information may be helpful if families are planning future pregnancies.

Our booklet Deciding about a post mortem examination provides more information