Recurrent miscarriages: your questions answered

Recurrent miscarriages are rare but can have profound implications on the couple and their families. The couple want to know the reason for their losses and, if a treatable cause is found, to have a management plan for their next pregnancy. Early diagnosis and timely intervention can prevent further miscarriages.

Miss Petya Doncheva, renowned consultant gynaecologist and fertility expert explains everything you need to know about recurrent miscarriages, including causes and diagnosis.

What are the common causes of recurrent miscarriages, and how do you approach diagnosing these causes?

Recurrent miscarriages are when an early pregnancy loss happens three or more times. Recurrent miscarriages are rare and affect 1-2% of women (1-2 in 100). Despite popular belief, recurrent miscarriages do not necessarily happen one after the other and you may have healthy pregnancies in between.

Genetic factors (chromosomal abnormalities) are the most common cause of miscarriages and the risk increases with maternal age.

The risk of miscarriage can also be increased by the following factors:

• Blood clotting conditions (antiphospholipid syndrome).
• Abnormalities of the shape of the uterus.
• Hormonal conditions such as thyroid problems, diabetes, polycystic ovarian syndrome  (PCOS) or prolactin imbalance.
• Immunological factors.
• Male factors (poor quality sperm).

Lifestyle factors such as abnormal weight, excessive alcohol or caffeine intake and smoking can also contribute to the risk of miscarriage.

What is the significance of genetic testing in cases of recurrent miscarriages?

Chromosomal abnormalities (genetic errors) are the most common cause of miscarriages and affect 50% of pregnancy losses (1 in 2). The majority of couples have normal chromosomes themselves but in a small number of cases (around 6%), an abnormal chromosome can be present in one of the parents. Although it does not affect the parent, once passed to the embryo, it can cause a miscarriage.

It is possible to test fetal chromosomes from the pregnancy tissue obtained during the miscarriage. The parental chromosomes (karyotype) can be tested from blood samples from the couple and if an abnormal karyotype is discovered, the option of prenatal genetic testing may be offered.

What treatment options are available to couples who have experienced recurrent miscarriages and are trying to conceive again?

If a reason for the miscarriages is found, there may be a treatment available to improve your chances of a successful pregnancy. For women suffering from PCOS, we recommend targeting this with diet modifications, weight loss and metformin tablets. If we discover an abnormal thyroid function, treatment with thyroxin will be initiated.

Undiagnosed diabetes or abnormal prolactin levels require a referral to a consultant endocrinologist. If a blood clotting condition (antiphospholipid syndrome) is diagnosed, the treatment is with aspirin and blood thinning injections for the duration of the pregnancy. It is important to know that the pregnancy is at increased risk of complications and would be closely monitored by a team of healthcare professionals.

A 3D ultrasound can be used to detect uterine abnormalities (uterine septum) or space-occupying lesions of the uterus (polyps, fibroids). Surgical removal or correction of the anomaly is an option to treat such conditions after having a detailed discussion based on your individual circumstances.

In case of severe sperm abnormalities, a referral to a urology consultant is usually indicated.

How does age impact the risk of recurrent miscarriages and what steps can older couples take to optimise their chances of a successful pregnancy?

Miscarriages become more common as parents get older because the quality of the eggs and sperm decline. This association is stronger with the maternal age. Miscarriage is uncommon in women under 35 and only affects 11 to 15% of women. In women aged 40 to 45, miscarriage is much more prevalent and affects more than half of the pregnancies. Miscarriages are also more common if the father is more than 40 years old.

It is not uncommon for recurrent miscarriages to remain unexplained (i.e. all investigations come back normal). In this situation, there is no evidence that any form of treatment will reduce the risk of miscarriages. The chance of a successful pregnancy depends on the individual circumstances, including age, but there is some evidence that the prognosis is good even without any treatment. Although it is not possible to modify the age of the couple or the genetic content of their gametes, it is important to ensure that they lead healthy and balanced lifestyle and the female partner takes folic acid and vitamin D to reduce the risk of fetal anomalies.  It is important that those couples are cared for by specialists in miscarriages and reproductive medicine to ensure the best outcome.

Are there specific lifestyle changes or precautions that you recommend to individuals who have experienced recurrent miscarriages to improve their chances of a healthy pregnancy?

Being overweight (BMI> 25kg/m2) or underweight (BMI < 19 kg/m2) is associated with an increased risk of miscarriages. It is therefore essential to maintain a healthy weight.

You should stop smoking (including electronic cigarettes) and limit the amount of caffeine to drink to less than 200 mg/day (around two cups of tea or instant coffee). Additionally, you should avoid drinking regularly or to excess. The safety limit for women trying to conceive is 1-2 units once to twice a week and for man 14 units per week with no more than 3-4 units a day.

Having recurrent miscarriages can cause a lot of stress, therefore it is important that you and your partner take time to relax. If you are finding that the stress is becoming harmful to your relationship, you may find counselling support useful.

References and Support Groups:

Recurrent Miscarriage (Green-top Guideline No. 17) | RCOG

A new European guideline on Recurrent Pregnancy Loss - The Miscarriage Association

Home | Pregnancy After Miscarriage Support | Tommy's Miscarriage Tool (tommys.org)

The Miscarriage Association:Pregnancy Loss Information & Support

If you have suffered from a miscarriage and would like to seek the support of Ms Doncheva, do not hesitate to do so by visiting her Top Doctors profile today.