Recurrent miscarriage

What is a miscarriage?

A miscarriage is when you lose a baby before 24 weeks of pregnancy. If this happens in the first 12 weeks of pregnancy, it is known as an early miscarriage. Early pregnancy miscarriages affect one to two pregnancies in 10 (10-20%).

If this happens between 12 weeks and 24 weeks of pregnancy, it is known as a late miscarriage. Late miscarriages are less common and occur in 1 to 2 in 100 (1-2%) pregnancies.

What is recurrent miscarriage?

Recurrent miscarriage is when you have three or more early miscarriages. It affects 1 in every 100 (1%) couples trying for a baby.

Why investigate only after three early miscarriages?

Most women who have one or two miscarriages will go on to have a normal pregnancy the next time which suggests that their miscarriages were due to chance rather than an underlying cause.

Statistics have shown that there is more likely to be an underlying cause should a couple have three or more early miscarriages.

However, if the circumstances of the miscarriage are highly suggestive of a possible recurring cause, like late miscarriages occurring after 12 weeks the investigations can be offered after two losses.

Why does recurrent miscarriage happen?

There are known and possible causes that increase your risk of recurrent miscarriage. In more than half of all cases, the investigations undertaken are all normal and no definite cause is found. This is reassuring and the majority of women go on to have successful pregnancies in the future.

What are the possible causes of recurrent miscarriage?

Age

The older you are the higher your risk of miscarriage. The risk is highest among couples where the woman is older than 35 and man is older than 40 years of age. This relates to the higher chance of genetic abnormalities that arise at the time of fertilisation.

Antiphospholipid syndrome (APS)/blood clotting problems

APS is the most important treatable cause of recurrent miscarriage. It is a blood clotting problem. It happens when your immune system makes abnormal antibodies that attack fats called phospholipids in your blood.

This makes the blood more ‘sticky’ and likely to clot. It is not clear why these antibodies cause miscarriage. Other inherited blood clotting disorders which can cause late miscarriages are Factor V Leiden gene mutation, Protein S and Protein C deficiency. These inherited ones are not likely to cause early miscarriages.

Chromosomal abnormality

Chromosomes carry hereditary information in the form of genes. We inherit half our chromosomes from our mother and the other half from our father.

One of the parents may have a chromosomal abnormality called a ‘balanced translocation’ where part of the information from one chromosome is replaced on to that of another chromosome.

This does not cause any problem to the affected parent but can be passed to the baby which may cause an ‘unbalanced translocation’ resulting in a miscarriage.

Weak cervix

This is more likely to be a cause of late miscarriage. The cervix usually dilates during labour to allow the baby to be born.

Some women have weakness in the cervix which may cause it to dilate before 24 weeks of pregnancy. It is difficult to diagnose this when you are not pregnant.

This is more common in women who have had surgery or procedures involving the cervix. Most commonly this is a ‘LLETZ / loop’ treatment for pre-cancer changes.

The shape of your uterus (womb)

Some women may have an abnormally shaped uterus. This occurs from birth and can be associated with a weak cervix.

Diabetes and thyroid problems

Women with poorly controlled diabetes are at risk of miscarriage. However, those with well controlled Diabetes are not at an increased risk. Undiagnosed and therefore untreated thyroid disorders may cause miscarriage. However, if your thyroid problem is treated and controlled you are not at an increased risk of miscarriage.

Polycystic ovary syndrome (PCOS)

PCOS is one of the commonest female hormonal disorders. Women will have many small cysts (fluid filled sacs) in their ovaries and hormonal problems including high levels of insulin and androgen (male hormone). This may increase your risk of miscarriage especially if you are overweight. We do not know why this may happen.

Infection

Any acute infection that makes you unwell may cause a miscarriage but is not likely to cause recurrent early miscarriage.

What tests can the woman be offered?

Antiphospholipid antibody and thrombophilia screen

For diagnosis of APS, you need to test positive for one of the antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies) on two separate occasions at least 12 weeks apart.

We will offer these tests if any personal or family history of inherited clotting problem or you have had late miscarriage.

Karyotyping

You and your partner will be offered blood tests to look for chromosome abnormalities, such as a ‘balanced translocation’. This will be offered only if an unbalanced translocation is identified in the 3rd or subsequent miscarried pregnancy tissue or foetus on genetic testing.

Blood tests for diabetes and thyroid problems

Pelvic ultrasound scan

You will be offered a 2D or a 3D pelvic ultrasound scan to look at the shape of the womb and the ovaries.

What tests can be undertaken for the baby?

Karyotyping

On your third miscarriage you will be offered genetic tests to look at the chromosomes of the baby to see if there are any abnormalities that may have caused the miscarriage.

Post mortem

If you have had a late miscarriage you may also be offered a post mortem examination of your baby. You will need to give your written consent for these investigations and a health professional will discuss this with you beforehand.

What are my treatment options?

The treatment offered will depend on the cause found.

Treatment for antiphospholipid syndrome.

If you are diagnosed with APS you will be offered a low dose of aspirin and low dose heparin to start in early pregnancy. This treatment combination significantly reduces the rate of miscarriage by half.

Referral for genetic counselling

If either you or your partner has a chromosome abnormality, you would be offered the chance to see a specialist called a clinical geneticist at the Centre for Life. They will discuss with you your chances for future pregnancies and go through your options.

Monitoring and treatment of a weak cervix

If you have had a late miscarriage and have a diagnosis of a weak cervix you may be offered an operation to put a stitch in your cervix.

If it is unclear whether your late miscarriage was caused by a weak cervix, you may be offered vaginal scans in your pregnancy to assess the length of your cervix. If your cervix is shorter than it should be before 24 weeks you may be offered a cervical stitch.

Thyroid or diabetes management

If you are have a thyroid problem or diabetes, the doctor would specifically discuss further treatment with you.

Surgery to the uterus

If you have a correctable abnormality to your uterus, you may be offered surgery to correct it.

When no cause of found. Often, there is no cause found. Couples with no obvious cause found have a 75 in 100 (75%) chance of having a successful pregnancy next time.

Where there is no cause found there is no evidence that heparin and aspirin treatment reduces the chance of a further miscarriage.

Therefore, it is not advised to take these in cases where no cause is found. We recommend a healthy lifestyle and advise you to commence folic acid and vitamin D supplements pre-conception.

PGTA (Preimplantation genetic testing for aneuploidies)

This is not available on the NHS but may be explored privately. This can be considered in women with recurrent miscarriages with an intention to reduce miscarriages and time to conceive. It has however not been shown to result in a better live birth rate. You can discuss this with your specialist.

PGTA is a form of IVF where the egg and sperm are fertilised in the lab. The fertilised egg (embryo) is cultured for 5 days and on the 5th day one cell from the embryo is sampled and is tested for genetics.

The embryos are frozen until the genetic results are available and, if confirmed healthy are then thawed before transferring aiming for a pregnancy. The embryos with genetic abnormalities are not transferred thereby reducing the risk of miscarriage due to a genetically abnormal embryo.

It is important to note that IVF alone without genetic testing has the same chance of miscarriage as conceiving on your own.

What does this mean for us in the future?

You will have an appointment a few weeks after your third miscarriage. At this appointment you and your partner can discuss with the doctor the tests available to you in further detail and the likelihood of finding a cause for your recurrent miscarriages.

What would happen in my next pregnancy?

If you have suffered from recurrent miscarriage, you could self-refer and directly contact our Early pregnancy service (EPAC) to arrange an early pregnancy scan at seven weeks for reassurance.

As mentioned above, there is good chance of you having a successful pregnancy.

What are the latest updates from research trials that may be helpful for me to know for my next pregnancy?

Progesterone

PROMISE trial did not show any benefit of progesterone use during early pregnancy for women who have suffered from recurrent miscarriage. However, PRISM trial outcome, which was published, in New England Journal of Medicine in May 2019 did show that a subgroup of women who have had previous miscarriages and encountered fresh bleeding in current pregnancy (threatened miscarriage) may benefit from progesterone supplements. Please discuss this further with your doctor.

Thyroxine

TABLET trial did not show any benefit of use of thyroxine tablets in women who had thyroid auto antibodies but had normal thyroid function otherwise. Hence, this is not recommended if you just have antibodies but do not have a thyroid problem per se.

Immunotherapy

RESPONSE trial randomised women who had suffered from unexplained recurrent miscarriages to a synthetic protein (GCF/NT 100) or placebo during their early pregnancy. It showed no benefit of this treatment for improving live birth rate in women with history of recurrent pregnancy loss. There is no evidence to support role of immunotherapy for treating recurrent miscarriages.

How do I get more information regarding any ongoing or upcoming research studies?

Please ask your doctor for further information about any new research studies and their outcomes. If you are keen to take part in any research study, your doctor will give you information about current studies.

Finding help and support

Experiencing recurrent miscarriage is a stressful situation. If you are struggling to cope with your feeling, sometimes talking to someone may help you deal with the situation better.

Counselling support is available if you are finding it difficult to cope. Please ask the Nurses or Doctors for further contact details.

Contacts

Early Pregnancy Assessment Clinic (EPAC) 0191 282 5479
8.00am to 7.00pm 7 days a week
Ward 40 0191 282 5640
24 hours
Ward 40 Day Unit 0191 282 5618
8.00am to 8.00pm Monday to Friday