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Recurrent Pregnancy Loss – 5 Reasons

Recurrent Pregnancy Loss – 5 Reasons

If you’ve experienced a loss of any kind, I’m so sorry. All pregnancy loss is devastating. But you should know that no matter the timing, circumstances, or repeated nature of your miscarriages—it’s not your fault. It’s easy to fear that you did something wrong, or that you caused the loss in some way, but miscarriage is complex and still, in many ways, poorly understood.

Miscarriage used to be a taboo topic that no one talked about. In recent years it has become an increasingly open subject, with many celebrities and other famous people sharing their personal experiences of loss.

Still, it is often shrouded in silence and mystery as a part of everyday life. This can lead to difficulty grieving and recovering. This is especially true when someone experiences recurrent pregnancy loss (RPL), which means 3 or more consecutive miscarriages, although some providers will test and treat for recurrent miscarriage after 2 back-to-back losses.

Miscarriage Rates & Statistics

Miscarriage happens in 10 to 15 percent of known pregnancies, with most losses occurring before 12 weeks. In the second trimester, the miscarriage rate drops to less than 5 percent. (1)

About 1 percent of reproductive-aged women have recurrent pregnancy loss, or more than one miscarriage in a row. Of these women, 50 to 75 percent of them will have unknown causes. Around 65 to 75 percent of the women who have an unknown recurrent miscarriage cause will go on to have a healthy pregnancy, but the odds decrease with the number of losses and age of the mother. (2, 3)

5 Factors Relating to Recurrent Pregnancy Loss


When someone experiences even one miscarriage, it’s normal to want to know why. If recurrent miscarriages occur, it becomes increasingly important to understand the cause or causes. While 65 percent of women who don’t have a known cause for their recurrent losses will go on to have a healthy pregnancy, figuring out the reason(s) could lead to fewer losses. It could also theoretically help the 35 percent of women who aren’t expected to go on to have a healthy pregnancy on their own.

Many practitioners recognize a growing list of health factors that seem to be correlated to recurrent pregnancy loss, including immune problems, blood clotting disorders, genetic variants (like MTHFR), thyroid disease or insufficiency, and more. This article summarizes five common culprits in recurrent miscarriages.

(1) The Immune System

Inflammation is a protective response in the body. But when triggers for inflammation become chronic, the resulting problems can lead to many systemic issues, including infertility and miscarriage.

Inflammation plays a role in the implantation and growth of normal pregnancy. Excessive inflammation, however, can interfere and may lead to fetal resorption or miscarriage. (4) This can happen when natural killer cell levels are abnormal or when polymorphisms lead to the production of too many inflammatory cytokines or levels of TNF-alpha.

Autoimmune diseases can also increase the risk of abnormal immune function affecting healthy pregnancy development. Some autoimmune conditions that can be associated with recurrent pregnancy loss include:

  • Celiac disease (5)
  • Hashimoto’s thyroiditis (6)
  • Graves’ disease (7)
  • Systemic lupus erythematosus (8)

While these are the most common and those most associated with research, any autoimmune activity could potentially increase the risk for trouble conceiving or maintaining a pregnancy. (9) Inflammatory factors in the father can’t be entirely overlooked either, even though there is less research linking this directly with recurrent miscarriage.

(2) Blood Clotting Disorders

Related to inflammation and autoimmunity are blood clotting disorders. Some of them, like anticardiolipin syndrome, have roots in autoimmune dysfunction.

If a woman has clotting disorders on any level, they can become obvious during the early days or weeks of pregnancy. If your blood has a tendency to clot or to be too thick, it can result in cutting off the fetal blood supply or otherwise interfering with normal placental nutrient transfer. (10)

Blood clotting disorders relating to miscarriage include, in order from most to least common: (11)

  • Antiphospholipid syndrome
  • Sticky platelet syndrome
  • Tissue plasminogen activator deficiency
  • Factor V Leiden
  • Elevated levels of PAI-1
  • Elevated lipoprotein(a)

In a study done of 150 women analyzing the clotting factors relating to miscarriage, 25 percent of the women had more than one clotting factor present. More than 98 percent of women with these diagnoses will go on to have normal pregnancies when treated with low-dose aspirin and heparin to term. (12)

MTHFR is another genetic variant that has roots in clotting factors and recurrent miscarriage. Research has even found that risks for recurrent miscarriage and clotting disorders are compounded when both the mother and father have them, even if individually they would be considered low-risk. (13)

(3) Methylation

Methylation problems, and specifically MTHFR variants, can have a negative effect on pregnancy outcomes. While many doctors don’t automatically make this connection, the connection between MTHFR and miscarriage is as distinct as clotting disorders and miscarriage.

Methylation is an essential component of healthy cells and DNA. You can’t have viable sperm or eggs without healthy DNA. If methylation is compromised due to dirty genes or MTHFR variants that are not being addressed, this could lead to perpetually poor quality embryos, resulting in frequent miscarriages. (14)

Solving methylation and optimizing MTHFR isn’t as simple as just taking more folic acid. It’s not even solved by just taking more L-5-MTHF or folinic acid. Methylation is a complex process that requires multiple nutrients, including active B12, active B6, antioxidants, and many other supportive nutrients.

(4) Thyroid

The thyroid not only helps to control metabolism in the body, but it’s an important endocrine gland that can influence overall hormone balance. Pregnancy requires increased levels of hormones that must be balanced. Low thyroid hormone levels and other endocrine factors are estimated to cause as many as 12 percent of all miscarriages. (15)

Unfortunately, most doctors only test TSH, or thyroid stimulating hormone, to assess whether or not a thyroid is healthy. But free T3 and free T4—the active and accessible amounts of thyroid hormones—are far better labs to assess thyroid function and overall health. These levels can be low even if TSH is normal. Thyroid dysfunction in the early weeks of pregnancy can lead to early miscarriage, yet many OBGYN’s don’t test thyroid function in pregnant women until between 6 to 12 weeks gestation. Women with a history of recurrent miscarriages should have their thyroid health checked prior to getting pregnant to rule it out as a potential cause.

(5) Genetic Health of Mother and Father

Of all miscarriages, including those that are not recurrent, 60 percent are due to chromosome abnormalities that no one can control. These are random occurrences that can’t be prevented and don’t repeat in subsequent pregnancies. These types of errors do become more common the older a mother gets. (16)

In rare cases either the mother or the father will have what is known as a translocation. Genetic material passed on from this parent may result in chromosomally abnormal embryos. This contributes to a small percentage of recurrent miscarriages. (17) Fertility specialists can run tests, known as karyotyping, to determine whether or not these are causes in either parent. It is considered rare that this would be the cause, either in the general population or in the recurrent miscarriage population. (18)

While egg and sperm quality matter immensely for a healthy pregnancy outcome, there are larger epigenetic factors that should be considered when it comes to recurrent miscarriage. Recurrent pregnancy loss is defined as consecutive losses with the same father—so even the definition excludes the mother’s health alone as the only factor. (19)

Epigenetics—or how your DNA responds to your personal lifestyle, diet, and environment—can influence everything from the health of your eggs or sperm to how well your own body is able to flow through methylation processes and beyond. If either partner’s methylation or DNA is not optimally healthy, it can result in passing on compromised genetic material to the embryo.

The World Health Organization considers that as many as half of all pregnancy losses may be genetically normal (referred to as “euploid”), and therefore, may have issues that can be resolved to prevent future losses. (20)

Of course, there can be other contributing factors entirely. Nearly one-fourth of all pregnancies end because of random chromosomal abnormalities—the type that you cannot control or prevent. Even if you have recurrent pregnancy loss, some of your miscarriages will end because of these statistically “normal” reasons, making the problem feel that much bigger.

Uterine and other structural abnormalities can also cause recurrent miscarriages. (21)

The bottom line is that if you’re having repeated miscarriages, there isn’t one simple test to run. It will take a careful evaluation of your health history and factors relating to both the mother and the father to work toward a resolution and a healthy pregnancy.

How to Get Answers About Your Miscarriages

You don’t have to resign to the fact that you’ll keep having miscarriages. It may take some work, but you can find a practitioner (or a few) who will come alongside you to search for answers through testing. It is not normal to have multiple consecutive miscarriages, and if a doctor is telling you that it is, it’s time to get a second opinion.


There are a wide variety of tests that could be done to assess the reasons why you’re having miscarriages. Many are mentioned in the sections above, but a general workup for those experience repeated losses might include:

  • Physical examinations and ultrasound for structural abnormalities
  • Genetic testing and karyotyping for both partners
  • Lab testing to assess thyroid and other hormone function
  • Lab testing to check for clotting or autoimmune antibodies
  • Lab testing to look for nutrient or other deficiencies
  • Lab testing to assess reproductive hormones and egg reserve in the mother and to assess sperm health in the father

Any other tests could potentially be run based on a personal health history. If you’re experiencing recurrent losses, you should work with a MFM (maternal fetal medicine) specialist, reproductive endocrinologist, or other OBGYN who specializes in recurrent pregnancy loss.

In many cases, you will uncover a diagnosis and may be prescribed medication or a fertility treatment protocol to aid in a healthy pregnancy.

Optimize Your Body for Fertility

While you’re working with a practitioner (or waiting to see one), there are many things that you can do on your own. While you can’t treat your own blood clotting disorders or structural problems, there is one area where you can be proactive: methylation and epigenetics.

Whether you have MTHFR or other dirty genes, you can work to optimize your diet, lifestyle, and overall health approach to be one that is supportive of optimal health. You don’t have to view it as a “fertility diet” because in reality, healthy parents set the stage for all aspects of optimal health—including pregnancy.

4 proactive steps to support your fertility and health include:
  • Read Dirty Genes and follow the principles in the book that apply to you.
  • Make lifestyle changes to support healthy practices like sleep, stress relief, proper hydration, and even having fun.
  • Support your mental health by working with a therapist.

The Bottom Line

It’s hard to hold onto hope for a healthy pregnancy when you keep losing them. I have been there. No one knows better than you do what your desires are, and what direction you want to go with your treatment. What is right for one person won’t be for the next.

While repeating the same thing over and over won’t often solve the problem, getting answers about your personal health and body hopefully will. Happy endings come in many forms, whether you get and stay pregnant with your own eggs, conceive and become a parent through donor eggs, utilize a surrogate, become a parent through adoption, or ultimately choose to have a child-free life. There is no single right way to have a happy ending, but happy endings are indeed possible even after many recurrent miscarriages.

5 causes of recurrent pregnancy loss



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