Understanding Recurrent Miscarriage: Causes, Tests, Treatment and Support

Understanding Recurrent Miscarriage: Causes, Tests, Treatment and Support

Recurrent miscarriage means experiencing repeated pregnancy losses. The Royal College of Obstetricians and Gynaecologists (RCOG) defines recurrent miscarriage as three or more first-trimester miscarriages, although investigation may be appropriate after two miscarriages in some circumstances.

Causes can include chromosome abnormalities, antiphospholipid syndrome (APS), differences in the uterus and, particularly following later miscarriage, problems involving the cervix.

Importantly, many cases remain unexplained and the chance of a future successful pregnancy is often good.

Recurrent miscarriage is also sometimes called recurrent pregnancy loss (RPL).

At Innermost Healthcare, our approach is to review your individual pregnancy history, identify investigations that may genuinely be useful, discuss treatments supported by evidence and make an appropriate plan for your next pregnancy.

Find out about Miscarriage Care and Specialist Miscarriage Consultation at Innermost Healthcare

What is recurrent miscarriage?

Different professional organisations use slightly different definitions.

The Royal College of Obstetricians and Gynaecologists (RCOG) defines recurrent miscarriage as three or more first-trimester miscarriages. They do not have to occur consecutively and successful pregnancies may occur between miscarriages.

Importantly, RCOG also recommends using clinical judgement and considering investigation after two first-trimester miscarriages where there is concern that the losses may have an underlying cause rather than occurring sporadically.

The European Society of Human Reproduction and Embryology (ESHRE) considers recurrent pregnancy loss after two or more pregnancy losses.

In practice, assessment should therefore be individualised rather than simply waiting for an arbitrary number of miscarriages.

RCOG: Recurrent Miscarriage – Patient Information

ESHRE: Recurrent Pregnancy Loss Guideline

Early and late miscarriage are different

The timing and circumstances of a miscarriage can provide important information about its possible cause.

Most miscarriages occur during the first trimester. Chromosome abnormalities in the pregnancy are particularly important at this stage.

A miscarriage during the second trimester may require somewhat different assessment. Depending upon the circumstances, possible factors include the shape of the uterus, antiphospholipid syndrome, infection and problems involving the cervix.

This is why recurrent miscarriage assessment should consider what actually happened during each pregnancy rather than simply counting the number of miscarriages.

How common is miscarriage?

Miscarriage is common. Most miscarriages are isolated events and are followed by a successful pregnancy.

Recurrent miscarriage is much less common, with approximately 1 in 100 women experiencing three or more miscarriages.

One of the strongest factors affecting the chance of miscarriage is maternal age.

How does age affect the chance of miscarriage?

Chromosome abnormalities in eggs and embryos become increasingly common with maternal age. This is one of the main reasons miscarriage becomes more common as women become older.

RCOG provides the following population estimates:

These are population estimates rather than an individual’s precise chance of miscarriage.

Your personal chance also depends upon your previous pregnancy history and other clinical factors.

Importantly, increasing maternal age predominantly increases miscarriage through an increasing frequency of sporadic chromosome abnormalities in the pregnancy. It does not necessarily mean that a woman experiencing recurrent miscarriage has an underlying medical condition.

RCOG: Recurrent Miscarriage and Age

Why do recurrent miscarriages happen?

There is rarely a single simple explanation.

For many couples, appropriate investigation does not identify a definite cause. This can be frustrating, but an unexplained result does not mean that another miscarriage is inevitable.

Chromosome abnormalities in the pregnancy

Chromosome abnormalities are the commonest recognised cause of miscarriage.

RCOG reports that approximately 1 in 2 miscarriages (50%) occur because the pregnancy has developed with abnormal chromosomes.

Most of these abnormalities occur by chance when the egg, sperm or embryo is formed. Usually, both parents have entirely normal chromosomes.

Their frequency increases particularly with increasing maternal age.

Could one of the parents have a chromosome abnormality?

Occasionally.

A healthy person can carry a balanced chromosome rearrangement, such as a balanced translocation.

The carrier is usually completely healthy because they still have the correct overall amount of genetic material. However, some eggs or sperm may contain an unbalanced amount of chromosome material, potentially resulting in miscarriage or, less commonly, a baby with a chromosome condition.

RCOG reports that in approximately 6 in 100 couples who have experienced three miscarriages, one parent may have a chromosome rearrangement.

Parental chromosome testing – called a karyotype – can therefore be appropriate in selected circumstances.

Innermost Healthcare: Chromosome/Karyotype Testing

Where pregnancy tissue is available, genetic testing of the pregnancy itself can sometimes provide more direct information about whether a chromosome abnormality contributed to that particular miscarriage.

Innermost Healthcare: Genetic Testing Following Pregnancy Loss

Antiphospholipid Syndrome (APS)

Antiphospholipid syndrome (APS) is one of the most important recognised and potentially treatable causes of recurrent miscarriage.

APS is an acquired autoimmune condition associated with abnormal blood clotting and pregnancy complications.

Testing usually includes:

• lupus anticoagulant
• anticardiolipin antibodies
• anti-beta-2 glycoprotein I antibodies.

An isolated positive blood test does not necessarily mean that someone has APS.

Diagnosis requires the appropriate clinical history together with persistently abnormal laboratory results. Confirmatory antibody tests need to be positive on two occasions at least 12 weeks apart, with testing performed at least 6 weeks after a miscarriage.

Innermost Healthcare: Understanding Antiphospholipid Syndrome (APS)

Innermost Healthcare: Blood Tests including APS Testing

Can APS be treated?

Yes.

For women with recurrent miscarriage who fulfil the diagnostic criteria for APS, treatment during pregnancy with low-dose aspirin and heparin can improve pregnancy outcome.

This is different from routinely prescribing aspirin or heparin to everybody who has experienced recurrent miscarriage.

The shape of the uterus

Differences in the development or shape of the uterus can sometimes contribute to pregnancy loss.

These include congenital uterine differences such as a septate or bicornuate uterus.

Fibroids, polyps and intrauterine adhesions can also sometimes be relevant, depending particularly upon their size and position.

A good-quality pelvic ultrasound examination is therefore an important part of recurrent miscarriage assessment.

More specialised imaging may occasionally be recommended depending upon the findings.

What about the cervix and later miscarriage?

The cervix – the neck of the womb – becomes particularly important when a pregnancy has been lost during the second trimester.

In some women the cervix can shorten and begin to open too early, sometimes with relatively little pain or warning. This is commonly described as cervical insufficiency or cervical weakness and can contribute to late miscarriage or very premature birth.

This is different from the usual causes of an early first-trimester miscarriage.

It is particularly important to tell your clinician if you have had:

• a previous miscarriage after 16 weeks
• a previous spontaneous premature birth
• waters breaking early in a previous pregnancy
• previous cervical surgery such as a cone biopsy or some LLETZ procedures
• a previous cervical stitch
• a known difference in the shape of your uterus.

Depending upon your history, you may be offered transvaginal ultrasound scans to measure the length of your cervix during the second trimester.

If the cervix becomes short, options in appropriate circumstances may include:

• a cervical stitch (cerclage)
• vaginal progesterone
• continued specialist cervical surveillance.

A planned cervical stitch may sometimes be recommended on the basis of the previous pregnancy history without waiting for the cervix to shorten.

RCOG: Cervical Stitch – Patient Information

Thyroid conditions

Thyroid function is relevant to pregnancy and miscarriage.

RCOG recommends assessment of:

• thyroid function
• thyroid peroxidase (TPO) antibodies.

Having thyroid antibodies does not automatically mean that treatment is required. The result needs to be interpreted alongside actual thyroid function and the individual’s clinical circumstances.

Diabetes and other medical conditions

Poorly controlled diabetes can increase the chance of miscarriage and other pregnancy complications.

Where clinically appropriate, HbA1c can be used to assess longer-term glucose control.

Other endocrine investigations may be useful when suggested by the clinical history, for example abnormal menstrual cycles or symptoms suggesting a prolactin disorder.

This is one reason why recurrent miscarriage assessment should start with a careful consultation rather than simply ordering the largest possible panel of blood tests.

What about inherited thrombophilia?

Inherited thrombophilias are different from APS.

Routine inherited thrombophilia testing is not recommended for every woman with recurrent early miscarriage, because the evidence linking inherited thrombophilias with recurrent first-trimester miscarriage is considerably weaker than for APS.

There are circumstances in which thrombophilia investigation may nevertheless be appropriate, particularly according to the type and gestation of previous pregnancy losses and someone’s personal or family history of thrombosis.

Testing should therefore be considered individually.

What about immune tests and Natural Killer (NK) cells?

The relationship between the maternal immune system, implantation and miscarriage remains an area of considerable research.

However, outside established conditions such as APS, many proposed immune markers have not been shown to reliably identify the cause of recurrent miscarriage or select treatments that improve the chance of a live birth.

Tests involving Natural Killer cells, cytokines and other immune markers should therefore be considered separately from established recurrent miscarriage investigations and discussed with an understanding of the limitations of the available evidence.

Similarly, treatments such as steroids, intralipids and other immune therapies are not standard evidence-based treatments for unexplained recurrent miscarriage.

What about infection and chronic endometritis?

An acute infection can occasionally contribute to an individual pregnancy loss, but routine screening for a large number of infections is not normally recommended simply because someone has experienced recurrent miscarriage.

Chronic endometritis is an area of continuing research.

Investigation may be considered in selected circumstances, but it should not currently be regarded as an established explanation for a large proportion of recurrent miscarriages.

Does stress cause miscarriage?

Women frequently look back after a miscarriage and wonder whether something they did caused it.

They may worry about working, exercise, travelling, sexual intercourse, lifting something or experiencing a stressful event.

In the overwhelming majority of cases, nothing the woman did caused the miscarriage.

There is no good evidence that ordinary emotional stress is a direct cause of recurrent miscarriage.

Recurrent pregnancy loss can itself cause considerable anxiety, grief and psychological distress, and emotional and practical support are therefore important components of care.

What tests should I have after recurrent miscarriage?

There is no single “recurrent miscarriage test” suitable for everybody.

A good assessment starts with your pregnancy history.

We would normally review:

• the number of previous pregnancies
• the gestation of each miscarriage
• whether each pregnancy was confirmed by ultrasound
• previous live births
• any previous premature births
• previous pregnancy complications
• results of genetic testing of pregnancy tissue, if performed
• maternal age
• menstrual and fertility history
• medical and surgical history
• medications
• family history
• personal or family history of thrombosis
• previous investigation results.

Depending upon this assessment, investigations may include:

• antiphospholipid antibody testing
• thyroid function and thyroid antibodies
• HbA1c where appropriate
• pelvic ultrasound assessment of the uterus
• selected reproductive hormone investigations
• parental chromosome testing where appropriate
• genetic testing of pregnancy tissue where available
• other targeted investigations according to the individual history.

Find out about a Specialist Miscarriage Consultation at Innermost Healthcare

The aim is not simply to perform as many tests as possible. It is to identify which investigations are most likely to provide useful information for you.

What happens at a recurrent miscarriage consultation?

If possible, it is helpful to bring or provide copies of previous:

• ultrasound reports
• hospital or clinic letters
• blood-test results
• genetic or chromosome results
• laboratory results from pregnancy tissue
• relevant medical records.

At the consultation, we review each pregnancy individually rather than simply counting the number of miscarriages.

We can then discuss:

• whether further investigation is appropriate
• which tests are most likely to be useful
• which investigations are unlikely to change your care
• the significance of results you have already received
• your individual chance of a successful future pregnancy
• treatment where appropriate
• a plan for your next pregnancy.

Innermost Healthcare: Specialist Miscarriage Consultation

Can recurrent miscarriage be treated?

There is no single treatment for recurrent miscarriage.

Treatment depends upon whether a clinically significant factor has been identified.

Antiphospholipid syndrome

Low-dose aspirin and heparin can improve pregnancy outcome in women with recurrent miscarriage who meet diagnostic criteria for APS.

Thyroid conditions and diabetes

Recognised medical conditions should be appropriately treated and optimised before and during pregnancy.

Uterine abnormalities

Some differences in uterine anatomy require no treatment. Selected structural abnormalities may warrant further specialist assessment and occasionally surgery.

Cervical insufficiency

Following an appropriate late miscarriage or premature birth history, management may include cervical-length surveillance, progesterone or cervical cerclage.

Parental chromosome rearrangements

Genetic counselling can help explain the chance of future miscarriage and the available reproductive options.

Does progesterone prevent miscarriage?

Progesterone is frequently discussed following previous miscarriage, but the evidence needs to be interpreted carefully.

Current NICE guidance recommends vaginal micronised progesterone 400 mg twice daily for women who:

1. have had at least one previous miscarriage;
2. develop vaginal bleeding during their current early pregnancy; and
3. have an intrauterine pregnancy confirmed by ultrasound.

If a fetal heartbeat is subsequently confirmed, NICE recommends continuing treatment until 16 completed weeks of pregnancy.

Current evidence does not support routinely giving progesterone to every asymptomatic woman solely because she has previously experienced recurrent miscarriage.

NICE NG126: Ectopic Pregnancy and Miscarriage – Diagnosis and Initial Management

Does aspirin prevent miscarriage?

Not for everybody.

Aspirin has important evidence-based uses during pregnancy, including in the management of APS and prevention of pre-eclampsia in women meeting appropriate risk criteria.

However, taking aspirin simply because someone has previously miscarried is not the same as treating an identified cause of recurrent miscarriage.

Its use should therefore be considered individually.

Does IVF prevent recurrent miscarriage?

Usually not.

IVF is an important treatment for infertility, but IVF itself is not a general treatment for unexplained recurrent miscarriage.

Preimplantation genetic testing can have a role in particular circumstances, especially where one parent carries certain chromosome rearrangements.

For other couples, natural conception may continue to offer a good prospect of a successful pregnancy without IVF.

What happens if all my recurrent miscarriage tests are normal?

This is very common.

A substantial proportion of recurrent miscarriage remains unexplained despite appropriate investigation.

This does not necessarily mean that something important has been missed.

Because chromosome abnormalities can arise sporadically in individual eggs and embryos, it is possible to experience several miscarriages and subsequently conceive a chromosomally normal pregnancy.

What are my chances of having a successful pregnancy?

For many women, they remain good.

There is no single percentage that applies to everybody.

Your individual chance depends particularly upon:

• maternal age
• the number of previous miscarriages
• previous live births
• the gestation and characteristics of previous losses
• whether an underlying condition has been identified.

RCOG emphasises that even when recurrent miscarriage remains unexplained, most women still have a good chance of a successful future pregnancy.

Your individual pregnancy history is therefore much more informative than applying a single population statistic to everybody.

Care in your next pregnancy

Becoming pregnant again following miscarriage can be both exciting and extremely anxiety-provoking.

Medical treatment is only one component of good recurrent miscarriage care.

Support during another pregnancy may include:

• early access to an experienced clinician
• early ultrasound to confirm that the pregnancy is within the uterus
• confirmation of fetal heartbeat and appropriate development
• further reassurance ultrasound where appropriate
• prompt assessment if pain or bleeding develops
• progesterone when NICE criteria are met
• treatment of any condition identified by previous investigations
• cervical surveillance where indicated following a previous late miscarriage or premature birth.

Emotional support after recurrent miscarriage

Recurrent miscarriage can have a profound emotional impact.

Women and their partners may experience grief, anxiety, sadness, anger, guilt, difficulty sleeping or fear about trying for another pregnancy. Partners can also be significantly affected, sometimes in different ways and at different times.

Pregnancy after miscarriage can bring further anxiety. Milestones such as approaching the gestation of a previous loss, waiting for an ultrasound scan or experiencing symptoms that occurred in a previous pregnancy can be particularly difficult.

These reactions are understandable, and emotional support is an important part of recurrent miscarriage care.

Where can I find support?

Several UK organisations provide specialist information and support following pregnancy loss.

The Miscarriage Association

The Miscarriage Association provides information and support for anyone affected by miscarriage, including partners and family members. Support includes information, a helpline, online support and resources for pregnancy after miscarriage.

Miscarriage Association – Pregnancy Loss Support

Tommy’s

Tommy’s provides evidence-based information about miscarriage and pregnancy complications together with support and resources for people affected by pregnancy loss.

Tommy’s – Miscarriage Information and Support

Sands

Sands provides support following pregnancy and baby loss, including bereavement support, a helpline, online communities and local support.

Sands – Pregnancy and Baby Loss Support

Petals

Petals provides specialist counselling following pregnancy and baby loss and may be particularly helpful for women and couples who feel they would benefit from professional psychological support.

Petals – Pregnancy and Baby Loss Counselling

Support from your GP and healthcare team

If grief, anxiety or low mood is becoming difficult to manage, please discuss this with your GP, midwife or another healthcare professional.

Some people benefit from formal counselling or psychological therapy, particularly following repeated losses or a traumatic pregnancy experience.

Importantly, seeking psychological support does not mean that your emotional symptoms caused your miscarriages. Emotional distress is frequently a consequence of pregnancy loss and deserves appropriate recognition and support.

BabyReAssure – support during your next pregnancy

Following previous miscarriage, waiting between appointments during another pregnancy can be particularly difficult.

At Innermost Healthcare, BabyReAssure provides regular early pregnancy ultrasound and support for women who would value additional reassurance following previous pregnancy loss.

This can include weekly early pregnancy scans from approximately 7 to 13 weeks, depending upon individual circumstances.

An ultrasound scan cannot prevent a miscarriage caused by a chromosome abnormality, but supportive care can confirm appropriate development, provide reassurance and allow concerns to be assessed promptly.

Find out about BabyReAssure and Innermost Healthcare Miscarriage Care

When should I consider a recurrent miscarriage consultation?

You do not necessarily need to wait until you have experienced three miscarriages before discussing your history.

A specialist consultation may be particularly useful following two or more pregnancy losses, or earlier where there are particular concerns such as:

• a later pregnancy loss
• a previous premature birth
• an unusual pattern to previous miscarriages
• relevant medical or family history
• previous abnormal investigation results
• a known chromosome rearrangement
• concern about APS
• concerns about the uterus or cervix
• uncertainty about which investigations are appropriate
• planning another pregnancy following previous losses.

At Innermost Healthcare, our Specialist Miscarriage Consultation is consultant-led.

The purpose is to review what has happened, consider whether further investigation is appropriate, interpret investigations you have already had and formulate an individual plan for another pregnancy.

Find out about Specialist Miscarriage Consultation at Innermost Healthcare

Frequently asked questions about recurrent miscarriage

Are two miscarriages considered recurrent miscarriage?

ESHRE considers recurrent pregnancy loss after two or more pregnancy losses.

RCOG formally defines recurrent miscarriage as three or more first-trimester miscarriages but recommends considering investigation after two where there is concern that the losses may have an underlying cause.

What is the most common cause of miscarriage?

Chromosome abnormalities in the pregnancy are the commonest recognised cause.

Most occur sporadically rather than because either parent has a chromosome abnormality.

What blood tests are done for recurrent miscarriage?

Evidence-based assessment commonly includes testing for antiphospholipid syndrome and thyroid function, with other investigations selected according to the woman’s pregnancy and medical history.

Can I have recurrent miscarriage tests after two miscarriages?

Yes. Investigation may be reasonable after two miscarriages depending upon maternal age, the gestation and characteristics of the losses and your individual clinical history.

Does recurrent miscarriage mean I cannot have a baby?

No.

Even when recurrent miscarriage remains unexplained, many women subsequently have a successful pregnancy.

Does progesterone prevent recurrent miscarriage?

Progesterone is not routinely recommended for every woman simply because she has previously miscarried.

NICE recommends vaginal micronised progesterone for women with previous miscarriage who develop bleeding in a subsequent ultrasound-confirmed intrauterine pregnancy.

Should I take aspirin after recurrent miscarriage?

Not automatically.

Aspirin and heparin have an established role for women meeting diagnostic criteria for APS. Aspirin also has other uses during pregnancy, but previous miscarriage alone does not mean that everyone should take it.

Can a weak cervix cause miscarriage?

Cervical insufficiency can contribute to second-trimester miscarriage or very premature birth, but it is not a typical explanation for recurrent early first-trimester miscarriage.

Does miscarriage become more common with age?

Yes.

RCOG estimates miscarriage rates of approximately 11–15% under 35, 25% at 35–39, 51% at 40–44 and 93% from age 45.

When should I see a recurrent miscarriage specialist?

Specialist advice may be appropriate following two or more miscarriages, a miscarriage after 16 weeks, previous premature birth, abnormal test results or where there are particular medical, genetic, uterine or cervical concerns.

When should I seek urgent medical advice?

If you are currently pregnant, seek urgent medical assessment if you experience symptoms such as:

• heavy vaginal bleeding
• severe or worsening abdominal or pelvic pain
• shoulder-tip pain
• dizziness, fainting or collapse
• fever or feeling significantly unwell.

Depending upon the circumstances and stage of pregnancy, contact your local Early Pregnancy Assessment Unit, maternity service, NHS 111 or emergency services.

Call 999 for severe symptoms or an emergency.

Further information and support

For independent evidence-based information:

Royal College of Obstetricians and Gynaecologists (RCOG): Recurrent Miscarriage

RCOG Green-top Guideline No. 17: Recurrent Miscarriage

RCOG: Cervical Stitch (Cerclage)

ESHRE: Recurrent Pregnancy Loss Guideline

NICE NG126: Ectopic Pregnancy and Miscarriage

Miscarriage Association

Tommy’s

Sands

Petals

For Innermost Healthcare assessment and care:

Miscarriage and Recurrent Miscarriage Consultation

Antiphospholipid Syndrome (APS)

Blood Tests including APS Testing

Chromosome/Karyotype Testing

Genetic Testing Following Pregnancy Loss

BabyReAssure and Early Pregnancy Support

Written and medically reviewed by Dr Bryan Beattie MD FRCOG, Consultant in Fetal and Maternal Medicine.

Last medically reviewed: August 2026.

This information is intended to support rather than replace individual medical assessment. The investigations, treatment and pregnancy surveillance appropriate for you will depend upon your pregnancy history, age, medical history and previous investigation results.

Bryan Beattie Lead Consultant in Fetal Medicine

Dr Robert Bryan Beattie MB BCh BAO MD FRCOG Dr Beattie qualified in 1983 from Queen’s University Belfast and is sub-specialty trained in Fetal and Maternal Medicine. He also holds the RCOG/RCR Joint Diploma in Obstetric Ultrasound. He was a founder member of the British Maternal and Fetal Medicine Society and is an internationally recognised pregnancy expert who is regularly called upon to speak at conferences and events. Dr Beattie is the founding Chairman and Trustee of the Innermost Academy, a registered charity dedicated to improving education in pregnancy care.

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