Recurrent pregnancy loss. What to do when spontaneous miscarriage becomes a pattern
A spontaneous miscarriage is one of the most common complications of pregnancy and occurs in 10 to 15% of clinical pregnancies (pregnancies which we’ve initially been able to visualise on an ultrasound). Miscarriages can occur whether the pregnancy was conceived naturally or through assisted reproduction treatment.
It is considered to be a spontaneous miscarriage when the pregnancy is lost before week 20 of gestation. This can be early (if it happens before 12 weeks), or late (if it’s after 12 weeks). The majority of miscarriages, however, usually occur before week 10 of pregnancy.
At our fertility clinic in Spain it is considered to be recurrent or habitual miscarriage when a female miscarries spontaneously two or three times in a row. This situation, which is uncommon, occurs in 1% (women with more than three consecutive miscarriages), and 5% (more than two consecutive miscarriages), of the population. After two miscarriages in a row, the risk of miscarrying again is approximately 20%. After a third pregnancy loss, this risk increases to 30%. However, we must also remember that the likelihood that the next pregnancy will be viable and progress as expected is between 50 and 70%.
What might be the causes of a spontaneous miscarriage?
Normally the main cause of a miscarriage tends to be genetic abnormalities or fetal development abnormalities, while maternal causes are generally secondary. Both types of causes may be sporadic or permanent.
In addition, other causes of miscarriage are associated with genetic problems and chromosome issues in the embryo, maternal age, thrombophilia (acquired or hereditary hypercoagulation), such as antiphospholipid syndrome, or genetic mutations on normal blood clotting factors. Endocrine disorders that are poorly controlled such as diabetes mellitus, immune conditions, abnormalities in uterine anatomy or abnormalities in the sperm or its quality may also be the reason behind spontaneous miscarriage.
How do we help couples who are dealing with recurrent spontaneous miscarriage?
At our fertility clinic in Spain, when talking about a female with a history of two or more spontaneous miscarriages, whether she conceived naturally or through assisted reproduction treatment, we re-evaluate the couple and go over each of the possible causes, both at the embryo and maternal level.
To try to find a cause we carry out a complete, thorough study on the couple in which, among other tests, we will order karyotype testing for both parents. To rule out sperm issues we can perform an analysis called sperm FISH and a sperm DNA fragmentation test. Additionally, we will assess the uterine cavity with a hysterosonogram and/or a hysteroscope which will allow us to rule out malformations, chronic inflammation, polyps and uterine fibroids, etc.
Another study that can provide us with more information about these recurrent miscarriages is the presence of the most frequent thrombophilias, which we can study with a simple blood test. We should also rule out endocrine and metabolic problems that are not being controlled. If possible, we should even perform a chromosome analysis on the embryo tissue recovered from the products of pregnancy (after the D&C is done), trying to avoid contamination with maternal tissue as best as possible, as this could give us incorrect information.
In terms of possible psychological causes in these situations, though it’s been proven that there is no cause and effect relationship between psychological stress and recurrent miscarriage, at URE Centro Gutenberg we believe it is essential for couples to get psychological counselling if they’ve received this diagnosis.
Is it always possible to determine the cause of a spontaneous miscarriage?
Unfortunately, despite all of the testing and studies we’ve mentioned, and even other analyses which could be performed, between 50 and 75% of couples who miscarry won’t be diagnosed with a specific cause, and this is known as idiopathic recurrent miscarriage.
It is, however, important to keep in mind that, like with everything in assisted reproduction, the female’s age is one of the main prognostic factors.
Therapeutic or treatment alternatives in this situation will depend on whether the cause is unknown or, on the contrary, if we have determined a condition or reason that is triggering recurrent pregnancy loss in the female.
At present there are many studies and developments in reproductive immunology, endocrinology, genetics… meaning we are able to produce diagnoses that are increasingly more precise and accurate, which would require more specific therapeutic interventions. On the other hand, it will always be important to take a multidisciplinary approach when it comes to assessing couples and the studies and treatments for recurrent miscarriage.
Have you experienced recurrent miscarriage and would you like to consult with a specialist about the possible causes and treatments? At URE Centro Gutenberg we can help you. Request an appointment with us online and we will study your case and offer you the best solution.