What are the causes of stillbirth?

On this page

Problems with the placenta

Problems with the umbilical cord

Genetic problems

Pre-eclampsia

Infections

Other conditions linked to stillbirth

Investigating why your baby was stillborn

Tommy's research on causes of stillbirth

Sources of support after stillbirth

What causes stillbirth?

Sadly, it’s not always possible to find a reason why a baby was stillborn. This can be so hard to hear when you’re grieving your baby and want to understand why your baby died. It’s important to remember that stillbirth is very unlikely to be caused by anything you’ve done or not done.

The latest report on stillbirths in the UK showed around 34% of stillbirths were unexplained. But we do know some causes of stillbirth and explain the most common causes here.

Problems with the placenta

Many stillbirths are linked to problems with the placenta. The placenta is attached to the lining of the womb and is connected to the baby by the umbilical cord. It links the mum or birthing parent’s blood supply to the baby. 

If the placenta does not work properly, the baby does not get enough nutrients or oxygen for them to grow or develop. This is called fetal growth restriction (FGR).

Sometimes, a post-mortem examination can help to diagnose FGR by comparing the size of baby’s liver and brain. If the baby’s brain is more than 4.5 times bigger than its liver, then this makes it more likely that the baby had FGR.

Placental abruption

Sometimes the placenta can separate from the womb before the baby is born. This is called placental abruption. It can lead to stillbirth because the separated placenta is no longer working as it should and will not give the baby the oxygen it needs to survive. 

In most cases it is not always clear why placental abruption has happened. In very rare cases it can be caused by injury to the stomach such as in a car accident. Or it is sometimes linked to conditions such as  pre-eclampsia or FGR.

Symptoms of placental abruption are: 

• pain in the abdomen or back (usually severe)
• contractions (tightenings of your womb that may feel like strong period cramps)
• tender womb
• vaginal bleeding.

Speak to your midwife, GP, or local maternity unit straight away if you think you have symptoms of a placental abruption. If you are unable to contact them, call 111 for advice. Call 999 if you have severe bleeding or pain that is making you feel very unwell. 

Read more about placental abruption.

Problems with the umbilical cord

Problems with the umbilical cord are one of the main causes of stillbirth. The umbilical cord links the placenta to your baby. It has blood vessels that take nutrients and oxygen to the baby and take away waste products.  

If your waters break before labour starts, the cord can slip down through the entrance of the womb (cord prolapse). This can stop the baby getting all the oxygen they need.

Signs of cord prolapse are:

• feeling the cord in your vagina or seeing it
• your baby has a slow heart rate. 

Some women and birthing people have no signs.

Other problems include the cord becoming knotted or wrapped around the baby or problems with the blood vessels in the cord.

Genetic problems

Around 8% of stillbirths in the UK are linked to genetic problems in the baby. You may hear these called congenital abnormalities. There are a variety of different genetic conditions which can be linked to stillbirth including:  

• Downs syndrome (3 copies of chromosome 21)
• Edward’s syndrome (3 copies of chromosome 18)  
• Patau’s syndrome (3 copies of chromosome 13).  

You may be offered detailed testing for specific genetic problems depending on your individual case.  

Pre-eclampsia

Pre-eclampsia is a condition that affects some people in pregnancy, usually after 20 weeks. Signs of pre-eclampsia include high blood pressure and protein in your wee.

If you are told you have pre-eclampsia, it is important to go to all your appointments to check your blood pressure and wellbeing. You may be offered early birth through an induction or c-section to prevent complications.  

Read more about pre-eclampsia. 

Infections

Stillbirth can be caused by infection. 

Bacterial infections can move from your vagina to your womb. These can cause inflammation of the placenta and membranes around the baby (called chorioamnionitis) or the umbilical cord (funisitis).

Other infections that can cause stillbirth include:

• rubella (German measles)
• Lyme disease
• toxoplasmosis
• parvovirus
• coxsackie virus
• cytomegalovirus
• Herpes simplex
• listeriosis
• leptospirosis
• malaria
• Q fever.

Read more about infections in pregnancy.

Other conditions linked to stillbirth

There are some other conditions that have been linked to stillbirth: 

• intrahepatic cholestasis of pregnancy (ICP) or obstetric cholestasis – a condition affecting the liver
• pre-existing health conditions such as diabetes
• gestational diabetes
• bleeding heavily before or during labour
• preterm birth.

There are also things that increase your risk of stillbirth that you may be able to do something about. These include:

• smoking
• alcohol, recreational or illegal drugs, and caffeine
• being obese
• going to sleep on your back after 28 weeks of pregnancy.

Risk factors are not the same as causes. Some people who have all the risk factors will not have a stillbirth and some people who have none of them will still have one.

Read more about preventing stillbirth. 

Investigating why your baby was stillborn

It’s understandable that you may want to know why your baby died.  

Investigations after your baby has died can find out important information. Examination of the placenta, genetic tests on the baby or a post-mortem can sometimes give you answers or help rule out possible reasons for the stillbirth. Your midwife or doctor can talk to you about the different options and help support you.  

You should be offered an appointment to talk to a doctor about the birth and to discuss the results of the post-mortem and any other tests, if you chose to have these done. This is usually about 3-4 months after your baby has died to allow the results of the investigations to be completed. It may be hard for you to think about trying for another baby, but this appointment is also an opportunity to talk about this.

It’s also usual for the hospital to review what happened and the care that you and your baby received. This can also help you understand why your baby died.

Read more about investigations and appointments after stillbirth. 

Tommy's research on causes of stillbirth

Without more research, we will never know why so many babies die before birth. Tommy’s Manchester Research Centre is focused on learning more about the main causes of stillbirth and how it can be prevented.

The Manchester Placenta Clinic is a specialist service for pregnant women and birthing people at risk of placental problems, which can potentially lead to fetal growth restriction. We believe most stillbirths could be prevented and we want to find out how. 

The Rainbow Clinic is a specialist service for women and birthing people who are pregnant after stillbirth. This was developed at our Manchester Research Centre, but there are now Rainbow Clinics at several places in the UK. 

Our research depends on fundraising and donations. Find out more about how you can support our research. 

Sources of support after stillbirth

You can talk to our Tommy’s midwives for free on 0800 0147 800. We are open 9am to 5pm, Monday to Friday. Or you can email them on [email protected].  

If you are of Black or Mixed-Black heritage you can book a call on the specialist helpline that we run in partnership with the Black maternal health organisation Five X More, if that feels more appropriate for you. We may also be able to get free bereavement counselling for you with the bereavement counselling organisation Petals.  

We also have a very warm and supportive a  baby loss support group on Facebook where you can talk to other parents who have lost a baby. 

Other support organisations

Ebony Bonds Bereavement Support offers compassionate help to Black bereaved families after baby loss.

Cruse Bereavement Care offers six sessions talking to a trained bereavement volunteer.  

Sands is a support charity for anyone who has experienced the loss of a baby. They can put you in touch with other parents who have had stillborn babies and will be happy to listen and talk.

Saying Goodbye offers support, advice and a befriending service. You can also attend Saying Goodbye ceremonies across the country.

Child Bereavement UK has support groups, offers counselling and lots of online resources. They can help siblings through a bereavement.

Twins Trust has information and support for those who have lost a multiple birth baby.

Petals Charity can offer specialist counselling free of charge to bereaved parents whose babies were born in certain hospitals across the UK.

Teddy’s Wish offers free counselling sessions for parents after stillbirth.

The Lily Mae Foundation offers up to 6 free fortnightly sessions with a trained support worker who has experienced baby loss.