Recurrent Miscarriage: Understanding the Causes and Treatment Options

The American Congress of Obstetricians and Gynecologists (ACOG) defines recurrent pregnancy loss as having two or more miscarriages. However, some experts state that three or more consecutive miscarriages are considered recurrent miscarriages. Regardless, the condition is relatively rare, affecting just 1% of couples.

Recurrent miscarriage can fall into two groups, early recurrent or late recurrent. Early miscarriage happens within the first trimester, which is the first twelve weeks of pregnancy. It can often be due to genetic problems with the embryo. Late miscarriage can have multiple causes and happens after the first trimester. 

These miscarriages typically only take into account the loss of a clinical pregnancy, not a chemical pregnancy. A clinical pregnancy is defined as a doctor being able to find clinical evidence of a pregnancy, such as placenta, fetal pole, or a gestational sac on an early ultrasound. A chemical pregnancy happens before there is evidence of a pregnancy other than a positive test. At either the early or late stage generally requires a visit to a specialist who may be able to find out a possible cause.

They are not considered common. Miscarriage, on the other hand, is more common and is thought to affect 15 to 20% of all pregnancies. It only happens to around 1 to 2%  of couples trying for a baby.

Certain risk factors are associated with repeat pregnancy loss. Generally, they are linked to the possible causes of miscarriages.

• Uterine problems like an abnormally shaped womb

• Thyroid disorders

• Immune disorders

• Blood clotting disorders

• Age

• History of miscarriages

There are various possible causes of multiple miscarriages. Unfortunately, even a specialist may be unable to determine the root cause. However, having more than one miscarriage does not automatically mean you won’t go on to have a healthy baby in the future. Investigations and treatments may be able to help you conceive and deliver.

Thyroid conditions

Thyroid problems are associated with an increased risk of miscarriage and other pregnancy issues. In particular, hyperthyroidism can be problematic. If you have immune disorders related to the thyroid, you may have higher levels of thyroid antibodies. Increased thyroid antibodies can pose a higher chance of miscarriage. It is important to try to control thyroid conditions and levels before conceiving. Many doctors should also check thyroid levels during early pregnancy.

Blood clotting disorders

Blood clotting disorders may have “sticky blood” as a symptom. This can affect blood flow to the placenta, sometimes resulting in clots that impair function. Disorders may also lessen the amount of oxygen and nutrients the embryo receives, elevating the risk of miscarriage. Blood clotting disorders can include antiphospholipid syndrome or systemic lupus erythematosus. Typically, women can be screened for antibodies and prescribed treatment if necessary.

Uterine issues

Individuals with an abnormally shaped womb may be more susceptible to miscarriages. A bicornuate uterus is when the womb is heart-shaped and looks like it has two sides rather than one pocket. It’s the most common abnormal shape compared to others like unicornuate. Fibroids and polyps might also be linked to repeated pregnancy loss. Generally, womb issues can be picked up on an ultrasound.  

Genetic causes

Rarely, one or both individuals in a relationship may pass on an abnormal chromosome each time an egg is fertilized, leading to recurrent miscarriage. Such as translocation, when a piece of one chromosome is transferred to another chromosome. Alternatively, there is a chance that an embryo can receive an abnormal number of chromosomes during fertilization. This is not linked to a medical condition and happens randomly, but the chance of it occurring can increase with age.  

Cervical incompetence

Cervical weakness or incompetence is when the cervix does not stay long and tightly closed during pregnancy. Instead, it becomes shorter, weaker, or opens before you are ready to deliver. It is linked to miscarriage as well as premature birth. Fortunately, there are treatment options for cervical insufficiency.

Low progesterone

Low progesterone in pregnancy is thought to be associated with recurrent miscarriage. However, more research needs to be done, and doctors are still unsure why this happens. In some cases, women who had recurrent miscarriages were asked to supplement with progesterone and went on to have healthy, successful live births.

More than half of women experiencing repeated miscarriages may never learn of the cause of the loss. Though doctors might find clues, a definitive answer may not become apparent. Still, your doctor may use the following to determine the reason for the repeated loss.

• Evaluation of medical history and previous pregnancies

• A physical exam and pelvic exam

• Blood tests to determine genetic causes

• Imaging such as ultrasound

• Blood clotting studies

The key to treating and managing your multiple miscarriages is finding a cause. If a cause is found, your doctor will likely be able to prescribe miscarriage treatments. Unfortunately, causes aren’t always easy to diagnose, and your doctor may not have guaranteed ways to avoid a future miscarriage.

Examples of possible treatment options include:

• Medications for blood clotting disorders, thyroid problems, and immune disorders

• Corrective surgery for uterine problems

• A cervical stitch (cerclage) for an insufficient cervix

• Genetic counseling

• Fertility treatments using donor eggs or sperm for chromosome translocation

If the cause cannot be found and a treatment isn’t readily available, all is not lost. Your doctor may be able to prescribe other treatments and recommend changes to increase your chances of having a successful pregnancy. Progesterone supplementation, early testing, lifestyle changes, and supporting your overall health may be able to help.

That being said, if you are experiencing repeated miscarriages, make sure you’re emotionally healed as well as physically healed before trying again. While your doctor can give you the medical all-clear, you and your partner are the only ones who know when you’re mentally ready. Seek support from friends, family, or an online community if you desire. You can also privately support your mental health through journaling, meditation, or other activities. If you decide not to try and get pregnant again, that is okay too. There are no right or wrong answers, only what’s best for you and your health.