A miscarriage is the loss of a pregnancy before 24 weeks. The main sign of a miscarriage is vaginal bleeding. This may be followed by cramping and pain in the lower abdomen.
On this page
Things that affect your risk of miscarriage
- Your age
- Your partner’s age
- Previous miscarriages
- Previous live births
- PCOS diagnosis
- Previous pregnancy history
- Previous medical history
General UK miscarriage statistics
Most miscarriages happen in the first 12 weeks, known as early pregnancy.
Many miscarriages in the first trimester are caused by chromosomal abnormalities (problems in development) in the baby but it is thought that around half have underlying causes.
- An estimated 1 in 5 pregnancies ends in miscarriage (1 in 6 if we only count women who realised/reported the miscarriage)
- Around 11 in 1,000 pregnancies are ectopic
- About 1 in 100 women in the UK experience recurrent miscarriages (3 or more in a row)
- More than 6 in 10 of women who have a recurrent miscarriage go on to have a successful pregnancy
Risk of miscarriage after 12 weeks (second trimester)
The risk of miscarriage greatly reduces in the second trimester. This is called late miscarriage.
- Around 1-2 in 100 women have a miscarriage in the second trimester
Risk of miscarriage by week of pregnancy
Reliable research and statistics breaking down the risk of miscarriage by week of pregnancy don’t really exist.
Most women are very aware of the rate of miscarriage falling by the end of week 12 and this is supported by a lot of research, but there is another point earlier that the risk also goes down.
According to one study, once a pregnancy gets past 6/7 weeks and has a heartbeat, the risk of having a miscarriage drops to around 10%.
Many women will not be aware of this point and commonly the heartbeat is not checked until the first ultrasound scan around week 11/12, but those who have had fertility treatment or are having early scans for other reasons will be able to date their pregnancy accurately and will know when they have passed this milestone.
Risk of recurrent miscarriage
Recurrent miscarriage is 3 or more miscarriages in a row.
- After each miscarriage your risk of another increases
- 1 in 100 women experience recurrent miscarriage
- If the cause is unknown, 6 out of 10 women who have had three miscarriages will go on to have a baby.
- The cause is unknown in around half of cases of recurrent miscarriages
Study shows risk decreases as pregnancy progresses
One research study of more than 300 women with a history of recurrent miscarriage showed that those who saw a heartbeat at 6 weeks of pregnancy had a 78% chance of the pregnancy continuing. It also showed that seeing a heartbeat at 8 weeks increased the chance of a continuing pregnancy to 98% and at 10 weeks that went up to 99.4%.
Risk of miscarriage and IVF
Research suggests that assisted reproduction (in vitro fertilisation etc) has a small, if any, increased risk of miscarriage in itself as a treatment. The usual risks of age, father's age and previous pregnancy history apply.
Why miscarriage happens
We have information on the known causes of early, late and recurrent miscarriage here.
But too often health professionals are not able to tell women why they have had a miscarriage. This area of research is underfunded, with many taking an unhelpful (and unique to pregnancy) approach of ‘It was not meant to be’.
Research into why miscarriage happens is the only way we can save lives and prevent future loss. In 2016, Tommy’s opened the UK’s first national centre dedicated to miscarriage research.