What are the most common causes of recurrent miscarriage?

Suffering a miscarriage is devastating for any couple and unfortunately, some go on to experience repeated unsuccessful pregnancies. In this informative article, highly respected senior consultant in obstetrics, gynaecology and reproductive medicine Dr Simone Rofena expertly explains the most common causes of recurrent miscarriage and the key factors which can increase a person’s risk of suffering from the problem. The renowned specialist also offers reassurance on when to see a specialist and the next steps following repeated unsuccessful pregnancies.

How common is recurrent miscarriage?

Recurrent miscarriage is not an uncommon condition. It is estimated to affect one in three hundred pregnancies and in other studies, it has been shown to potentially affect one to two per cent of all women of reproductive age.

What are the main known causes of recurrent miscarriage?

The main cause, which explains at least eighty to eighty-five per cent of all cases of recurrent miscarriage, is a genetic problem in the process of conception. Although totally randomly formed at the time of conception in the vast majority of cases, a minority of cases of pregnancy loss can be explained by one or both parents being a carrier of a genetic problem. That is why it is strongly recommended for all couples experiencing recurrent miscarriage to undergo a simple blood test called a karyotype which is able to detect if either of the parents is a carrier of a chromosomal condition.

Other reasons for recurrent miscarriage can be a tendency to form blood clots (thrombophilia) which is genetically determined. Another known reason are autoimmune problems which are characterised by the immune system fighting against itself. Normally, this shouldn’t happen as our immune system should have a tolerance towards itself.

However, in some cases, a pregnancy is not tolerated as it is identified as something not of ‘ourself’ as fifty per cent of a baby’s genetic information is of paternal origin. Unfortunately, this can sometimes lead the maternal immune system to trigger an immune reaction against the baby which causes the miscarriage.

Lastly, there are some general health conditions which might determine an increased risk for miscarriage, including some autoimmune diseases like diabetes, thyroiditis, rheumatoid arthritis and Crohn’s disease.

What are the risk factors that might influence recurrent miscarriage?

There are a series of risk factors which we know can increase a patient’s risk of experiencing recurrent miscarriage. The most common is having had a previous miscarriage as this suggests there may be an underlying issue. It is the job of a recurrent miscarriage specialist to try and identify this underlying condition with the help of necessary tests.

As I discussed previously, there might be chronic health conditions at play which can increase these risks. In other cases, the presence of uterine or cervical problems can increase the risk of recurrent miscarriage, such as fibroids or polyps in the uterus or a condition called septate of the uterus. Uterine malformations can often be a cause of recurrent miscarriage and they can be easily identified with a scan or magnetic resonance and then surgically corrected.

Other important factors to consider are smoking, alcohol and use of drugs which need to be clearly identified through conversations with the patient about their habits and lifestyle. If the specialist identifies one of these areas as a likely cause of recurrent miscarriage, it is strongly recommended that the patient is able to make the necessary lifestyle changes.

Additionally, an excessively high or low body weight can also represent a risk of miscarriage so this should also be addressed where possible. Lastly, invasive prenatal tests can also be a possible cause of miscarriage and unfortunately this form of testing always carries a risk. Although invasive prenatal tests are very helpful in most cases, the patient needs to be informed of the associated risk of miscarriage.

Might recurrent miscarriage indicate serious health problems?

As mentioned previously, some general health conditions can be an underlying cause of recurrent miscarriage. That is why it is always good to have a general profile of the patient’s health and to run some tests to assess liver function and thyroid function and to establish a metabolic profile, for example.

These forms of testing should be always requested in cases of recurrent miscarriage because we might find that an underlying problem is affecting other areas of the body, eventually contributing to recurrent cases of miscarriage.

What happens after a certain amount of recurrent miscarriages?

Typically, following two miscarriages the specialist should have a discussion with the patient about making some appropriate investigations to try and determine the cause of recurrent miscarriage. Experiencing even one miscarriage is devastating for any couple so the specialist should do whatever they can to try to identify the possible cause as soon as possible so the appropriate treatment can be put in place.

The good news is that in most cases, once the cause of recurrent miscarriage has been identified, there are effective means of treatment available which increase our patients’ chance of achieving a successful pregnancy.

Dr Rofena is a highly esteemed senior consultant in obstetrics, gynaecology and reproductive medicine who specialises in fertility problems and recurrent miscarriages. If you would like to schedule a consultation with Dr Rofena, you can do so by visiting his Top Doctors profile.