What is recurrent miscarriage?

Recurrent miscarriage, while rare, is an unfortunate condition which affects many prospective parents. Mr Ibrahim Bolaji, a leading gynaecological surgeon and infertility specialist, explains all you need to know about this unfortunate problem.

What is recurrent miscarriage?

A miscarriage is the loss of a pregnancy before it has developed enough to survive, usually defined as occurring in the first 24 weeks of pregnancy. In a miscarriage, the loss is spontaneous i.e., it has not been caused by medical or surgical means. Early miscarriage refers to loss of pregnancy in the first trimester-that is up to 13 completed weeks (3 months). Unfortunately, approximately 1 in 5 (20%) of pregnancies miscarry.  Late miscarriage occurs after 3 months of pregnancy but before 24 weeks, this is much less common however, occurring in only 1-2% of pregnancies.

What is defined as recurrent miscarriage varies between countries. In the United Kingdom recurrent miscarriage is when a miscarriage occurs three or more times in a row or back-to-back. Guidelines in the USA and Europe suggest a diagnosis of recurrent miscarriage should be considered after the loss of two pregnancies, even if there has been a successful pregnancy in between the two miscarriages. Recurrent miscarriage is not common and it affects 1 out of every 100 (1%) couples trying to have a baby, based on the UK definition.

The traditional reasoning is that miscarriage is not uncommon and so the chance of it happening again is high. Also, the chance of finding the cause is quite low. Therefore, there is a reasonably high chance that a patient might be subjected to tests and treatment for no gain. However there appears to be a shift in this thinking globally towards the concept that earlier testing may be beneficial after two losses.

What causes recurrent miscarriage?

There are many causes of recurrent miscarriage but unfortunately, it is not always possible for doctors to find out why it happens. The good news is that most couples who have had recurrent miscarriage have a good chance of having a baby in the future especially if tests results are normal. There are many factors that may contribute to this condition:

Biological clock

Age of the mother or the father is inversely proportional to the risk of having a miscarriage. It is more common in older women, and the risk gets higher the older you are. For women over 40, the risk of a miscarriage is about 50%.

Blood disorders

Some blood clotting disorders such as antiphospholipid syndromes (APS) can lead to sticky blood (more likely to clot) and recurrent miscarriage and in particular late miscarriages. Thrombophilia (an inherited condition that means that your blood may be more likely to clot) may also cause recurrent miscarriage, particularly late miscarriages, as can Factor V Leiden deficiency.

Genetic factors / Chromosomal factors

In about 2-5% of couples with the condition, one partner will have an abnormality on one of their chromosomes (these are genetic structures within our cells with genetic information that we inherit from our parents). Although this abnormality may not affect the parent, it can sometimes cause a miscarriage.

Abnormalities of the uterus (womb)

Abnormally shaped uterus, long standing womb infection, scarring of the lining of the womb and inclusion lumps inside the womb such as fibroids or polyps can increase the risk of recurrent miscarriage.

Thyroid abnormalities and thyroid antibodies

Thyroid abnormalities and thyroid antibodies (little molecules in the blood stream causing malfunction of thyroid) have been linked to increased risk of miscarriage

NK Cells (Natural Killer cells)

Some experts believe in the concept of natural killer cells in the uterus as contributing to infertility and miscarriage. These tests are very expensive and not available on the national health service (NHS).

Can a miscarriage be predicted?

Older couples, especially where the woman is over 35 and the man is over 40 have an increased risk of miscarriage. The risk of miscarriage also increases after each successive loss. Medical conditions (such as diabetes and SLE) and lifestyle conditions such as smoking, excessive alcohol and recreational drug consumption can increase the risk of a miscarriage.

What should a couple do after recurrent miscarriage?

Get medical assistance and embark on lifestyle changes such as good diet, weight management, avoidance of smoking, alcohol or recreational drug use.

How do you help women who have experienced recurrent miscarriage?

Investigations

Most parents never find out why they have miscarriage. Visiting a specialist will give them the opportunity to discuss the problems (Miscarriage afterthought counselling). This will lead to self-blame and guilt. The first part of assistance is to reassure the patients and conduct relevant investigations and offer appropriate treatment. The investigations will include the following:

Ultrasound scans to exclude abnormalities of the womb.

Blood tests for APS and for inherited antibodies of the blood clotting system and blood tests for other medical conditions (thyroid conditions and diabetes. Antibodies are immune response proteins that fight infection. In APS, abnormal antibodies are produced which attack a normal substance called phospholipid (which is why the antibodies are called antiphospholipid). Finally, blood tests for chromosomal tests for the parents (Karyotype).

Treatment

The treatment for recurrent miscarriage will depend whether a specific cause has been found based on the tests described. The treatment will fall into general and specific treatment.

Advice about any life style factors such as smoking, weight management and consumption of alcohol can be explored as this may improve the general health and wellbeing of the couple.

Psychotherapy in form of psychological support or counselling may be helpful as this condition can be very distressing and can put great strain in relationship.

Aspirin and blood thinning medications such as low molecular weight heparin injections during pregnancy in patients with APS or other blood clotting problems.

In the absence of any abnormality, blood thinning medicine may be advised but current evidence suggests this is not effective.

Some specialists treat with hormonal progesterone support in early pregnancy. There is however, no clear evidence about the benefit of this regimen. This will require further studies. Surgical correction of any treatable abnormality in the womb and cervix may be required. Artificial reproductive technology (ART) treatment such as IVF may be employed where abnormal chromosomes are detected. This may include the option of pre-implantation genetic (PGD) diagnosis to enable selection of only genetically normal embryos for the IVF. The challenges here include availability of the service, high cost, moral and religious beliefs. Also, the success rate for IVF may not be high to improve the chances of a successful pregnancy.

In more than 50% no treatment may be appropriate as in many couples no cause is found and no treatment has been found to be effective. The absence of any cause for miscarriage should be viewed positively as absence pathology makes it more likely that future pregnancies will be successful.

Is it possible to ever carry a full term?

In general, in most cases the chances of having a term pregnancy are very good especially if no cause is found. In this situation 75% (3 out 4) will be successful in having a live born baby. The chance is lower in older mothers and in those with an increasing number of miscarriages. Individualized chance of a livebirth can be gleaned after investigations and specific prognosis can be discussed in the specialist clinic.

Mr. Bolaji is a consultant obstetrician and Gynaecologist with over 40 years of experience; you can book a consultation with him by visiting his profile.