Family Health

Understanding and Preventing Recurrent Pregnancy Loss

Unfortunately, 20 percent of recognized pregnancies end in miscarriage. Chances are you or someone you know has experienced this kind of loss.

While we have made great strides in the transparency and discussion of pregnancy loss, many miscarriages are never spoken of. And for a person or couple grieving a miscarriage, it can be an isolating and overwhelming experience. That’s why it’s so important we continue the conversation.

What is recurrent pregnancy loss?

The American Society for Reproductive Medicine defines recurrent pregnancy loss as two or more failed pregnancies.

While each pregnancy deserves its own evaluation, two or more losses warrant a basic diagnostic workup – aimed at assessing potential causes to hopefully prevent future miscarriages.

What causes recurrent pregnancy loss?

I always break up causes for miscarriage into four categories:


An estimated 60 percent of miscarriages are found to be genetically abnormal. Some genetic causes can be age-related. For women under the age of 35, the risk of miscarriage is estimated to be around 9 to 12 percent. By age 40, the risk is closer to 50 percent. This dramatic increase can be attributed to advanced maternal age – or the associated increase in genetic abnormalities of pregnancies due to age.

In addition to age-related risk, 3 to 7 percent of couples with recurrent pregnancy loss carry a genetic abnormality that can be diagnosed by a blood test.


Congenital uterine anomalies (malformations of the uterus), uterine scarring or intracavitary fibroids (abnormal growths inside the uterus) can also contribute to recurrent loss. These can be diagnosed with the combination of sonohysterogram and 3D ultrasound.

A sonohysterogram is a test where saline is gently injected into the uterine cavity with simultaneous ultrasound. If any of the above conditions are diagnosed, they can often be repaired surgically to improve future outcomes.


Pregnancy requires attachment to the uterus and communication with maternal blood vessels in order to be maintained. Disorders that cause blood clots to form at the placental interface increase the risk for pregnancy loss.

In particular, a disorder called antiphospholipid antibody syndrome is associated with pregnancy loss. This can be diagnosed with blood work, and future pregnancies can be treated with blood thinners to hopefully prevent a loss. 


Endocrine disorders such as thyroid disease and diabetes have been shown to be associated with pregnancy loss. Thyroid disease and diabetes should be under strict control before attempting pregnancy again.

Other hormones that may be evaluated include prolactin. Evaluation of your overall ovarian function may also be necessary.

Hope after loss

Unfortunately, despite an exhaustive workup, we may never find a cause for the experienced losses. As miscarriage is so common, it’s important to know that prognosis for a healthy, viable pregnancy is still excellent after up to five losses.

Do not lose hope. You are not in this alone.

Contact Reproductive Health Specialists at Methodist Women’s Hospital if you have any questions regarding recurrent pregnancy loss.