Causes of stillbirth

Information on some of the causes of stillbirth.

In many cases when a baby is stillborn no cause can be found. The deaths of these babies remain ‘unexplained’, which can be particularly hard for grieving parents who want to understand what happened to their baby. However, whilst many stillbirths remain unexplained, there are a number of possible causes.

Failure of the placenta is the most common known reason for a baby to be stillborn. About half of all stillbirths are linked to complications with the placenta.

The placenta provides nutrients (food) and oxygen for the baby when he or she is growing in the womb, connecting the baby to its mother’s blood supply. It’s essentially the baby’s lifeline, crucial to growth and development.

If the placenta doesn't work properly, the baby won’t receive enough nutrients or oxygen and fails to grow or develop. This is called intrauterine growth restriction (IUGR) or fetal growth restriction (FGR).

Many stillborn babies affected by failure of the placenta seem otherwise healthy but are born smaller than expected.

Reduced fetal movements

Reduced fetal movements is not a cause of stillbirth but it is one if the signs that a baby may not be getting enough food or oxygen. Reduced fetal movement is noticed by the mother in around half of stillbirths.

This is why health professionals ask pregnant women to monitor the pattern of their baby's movements from 16-22 weeks onwards.

If you notice a change in your baby’s pattern of movements get in touch with the hospital immediately. Never go to bed at night worried about your babies’ movements.

Read more about how to monitor your baby's movements in pregnancy here.

Placental abruption

It is possible for the placenta to separate from the womb before the baby is born, this is called placental abruption and can lead to stillbirth as it means the placenta is not working as it should.

Placental abruption can be caused by a blow or impact to the stomach, or it could be linked to a condition such as pre-eclampsia or fetal growth restriction. Sometimes placental abruption occurs without any clear reason why this has happened.

The symptoms of placental abruption are:

  • pain in the back and abdomen
  • contractions
  • tender womb
  • vaginal bleeding.

If you are suffering from any of the symptoms above get medical help immediately.

Read more about placental abruption here.


One in 10 stillbirths happen because the mother contracts an infection.

Bacterial infections can move from the vagina into the womb, for example, group B streptococcus chlamydia, klebsiella, enterococcus, haemophilus influenza, mycoplasma or ureaplasma and escherichia coli (E.coli).

Other infections can harm a baby, including:

  • Rubella (German measles)
  • Flu
  • Lyme disease
  • Toxoplasmosis
  • Parvovirus
  • Coxsackie virus
  • Cytomegalovirus
  • Herpes simplex
  • Listeriosis
  • Q fever
  • Malaria

Read more about infections here.

Other conditions that are linked to stillbirth are

  • pre-eclampsia, a condition that occurs typically after 20 weeks - and causes high blood pressure in pregnancy
  • intrahepatic cholestasis of pregnancy (ICP), or obstetric cholestasis, a liver disorder affecting pregnancy
  • pre-existing diabetes
  • gestational diabetes
  • genetic defect in the baby (reason for around 10% of stillbirths)
  • excessive blood loss (haemorrhage) before or during labour
  • issues with the umbilical cord - a cord prolapse is when the umbilical cord slips through the entrance of the womb before the baby is born. This can stop the baby getting enough oxygen. The umbilical cord can also wrap itself around the baby’s neck
  • premature birth – when a baby is born before 37 weeks of pregnancy

Many parents desperately want to know what happened to their baby. A post-mortem can sometimes offer answers, or at least rule out reasons for, the stillbirth.

How Tommy's is helping

Without more research we will never know why so many babies die before birth.

The Tommy’s stillbirth research centre in Manchester is focusing on the main causes of stillbirth and how stillbirth can be prevented.

The Manchester placenta clinic is a specialist service for pregnant women at risk of placental problems that potentially lead to fetal growth restriction We believe the majority of stillbirths could be prevented and we want to find out how. 

Our research depends on fundraising and donations from those who care. To support our research click here.

1. NHS Choices [accessed 10/01/2018] Stillbirth causes,

2. NHS Choices [accessed 10/01/2018] Stillbirth overview

3. RCOG (2011) Reduced fetal movements guideline 2011, green-top guideline no. 57, Royal College of Obstetricians and Gynaecologists, London, England,

4. NHS Choices [accessed 10/01/2018] Stillbirth causes,

Review dates
Last reviewed: 31 August 2017
Next review: 31 August 2020