Recurrent Miscarriage: Why Does it Happen?

Recurrent Miscarriage

“Recurrent Miscarriage:  Why Does it Happen?” | myMindBodyBaby

Experiencing a miscarriage is devastating.  Each one carries its own unique tale of sorrow and loss.  Some happen earlier on and others later in the pregnancy.  Sometimes it comes on suddenly and is over before you can process what is happening and others are long, drawn-out affairs.

woman crying recurrent miscarriage

A sorrow, unlike others

Regardless of how and when it happens, you experience the loss of your hope, your dream of that child, and the plans you saw unfolding for your family’s future.  Those who have experienced recurrent miscarriages report it as a horrendous nightmare.  One where you know the ending, but you cannot do anything to stop it.

miscarriage sorrow, Recurrent Miscarriage

Life is not fair

I experienced a miscarriage after transferring our final embryo following our first round of IVF.  I figured we had been put through so much already that once we were pregnant, we were in the clear.  The loss, defeat, hopelessness of that one miscarriage was overwhelming.  It had taken so long to get to that point – and that little embryo was all we had left.  I cannot imagine the pain of multiple miscarriages.

miscarriage empty crib, Recurrent Miscarriage

What is a miscarriage?

A miscarriage is the loss of a pregnancy before the 20th week.  After twenty weeks the pregnancy loss is termed “stillbirth”.  There are a number of known causes of miscarriage, including:

  • genetic issues (accounts for roughly 50% of miscarriages)
  • hormonal issues
  • structural (cervical or uterine) abnormalities
  • serious illness
  • infection
  • environmental exposure
  • immunological issues
  • drug exposure

But while the list of possible reasons for miscarriage is known, for most individual miscarriages the exact reason is not known.  This means that your miscarriage may have resulted from something like a random genetic abnormality, but unless the fetal tissue is tested you won’t know the cause for certain.

medical reasons for miscarriage, Recurrent Miscarriage

In most cases, there is nothing you could have done to prevent the miscarriage.  It was not the result of something you ate, how or when you exercised, whether you had sex or any other action you may have taken, or not, while you were pregnant.  This is important.  So many women wonder if they are to blame.  They second guess everything they did – or didn’t do.  But you did not cause this.

Different types of miscarriage

In addition to there being different causes of a miscarriage, there are also different types of miscarriage:

  • Threatened Miscarriage: you experience bleeding and cramping, but your cervix remains closed. Fifty percent of threatened miscarriages resolve and the pregnancy proceeds; however, the other half of the time the pregnancy is lost.
  • Missed Miscarriage: you do not experience any bleeding or cramping and the miscarriage is diagnosed upon ultrasound. An embryo without a heartbeat or an empty gestational sac may be visible.  With time, your body may begin to expel the pregnancy tissue – in some cases, medical assistance to remove the tissue is required.
  • Inevitable Miscarriage: the cervix is open, there is significant bleeding and the pregnancy is lost.
  • Incomplete Miscarriage: sometimes your body is efficient at expelling all of the “products of pregnancy”, that is – the tissue and uterine lining. Other times some of the tissues remain in the uterus and you may require medical assistance in removing what is left.
  • Complete Miscarriage: your body has been able to expel all of the tissue associated with the pregnancy on its own.
Pregnancy Complications

There are also different pregnancy complications that end in miscarriage:

  • Blighted Ovum: a gestational sac forms, but no fetus develops inside of it. This is usually diagnosed upon ultrasound and in most cases, the tissues are reabsorbed into the uterus.  This is also known as an “anembryonic pregnancy”.
  • Ectopic Pregnancy: when the fertilized egg implants outside of the uterus, usually in one of the fallopian tubes. Often the hCG levels of an ectopic pregnancy will not increase properly, and this can be an indication that there is an issue.  You may not realize the pregnancy is ectopic until you experience bleeding and pain.  Pain may occur in your lower back, abdomen, or shoulder and you may also experience vomiting.  It is important to seek help immediately as ectopic pregnancies can induce damage if not taken care of.  Our resident nutritionist, Michelle, experienced an ectopic pregnancy following IVF – you can read about her story here.
  • Molar Pregnancy: the fertilized egg does not continue to develop properly after conception. The resulting miscarriage may be partial or complete and often times requires surgery to be fully removed.

The stats behind miscarriage

Unfortunately, miscarriage is not uncommon.  Fifteen to twenty percent of all pregnancies end in miscarriage, three-quarters of which happen before the end of the first trimester.  In fact, 30-50% of fertilized embryos are lost before a woman even misses her period.  Women who have had two or more miscarriages have an increased risk of subsequent miscarriage at 40%.  It is estimated that 5% of women have at least two consecutive miscarriages, while the risk of three or more is only at 1%.

Reasons for Recurrent Miscarriage

The term “recurrent miscarriage” is used to describe when a woman has experienced three more miscarriages in a row.  There are a number of different reasons that could lead to the devasting situation of experiencing recurrent miscarriages.

Immune System Disorders

It is estimated that 5-10% of recurrent miscarriages are due to immune system disorders.  This is when the women’s immune system negatively reacts to the pregnancy tissue leading to miscarriage.  Testing for specific antibodies is one step in understanding if an immune system disorder may be the reason behind multiple miscarriages.  Examples of immune system disorders that could lead to miscarriage are:

  • Antiphospholipid antibody syndrome: antibodies are produced that mistakenly attack phospholipids, a type of fat – and part of what makes up all cells. This causes damage to cells.  This cellular damage causes blood clots to form, and the abnormal blood clotting can lead to organ damage.
  • Autoimmune Thyroid Disease: the presence of thyroid autoimmunity and the production of thyroid autoantibodies (TAbs – antibodies produced in reaction to the thyroid gland). Some studies have shown that testing for thyroid function and the presence of TAbs in early pregnancy may help identify issues early.  If problems are detected treating with levothyroxine may be an option.
Hormonal Issues

A number of different hormonal issues may lead to recurrent miscarriage:

  • Low Progesterone: the corpus luteum is responsible for producing progesterone during early pregnancy. A defective corpus luteum does not produce adequate levels of progesterone and is one of the leading causes of early miscarriage (estimated at 35% of miscarriages).  Some studies have found that supplementing with progesterone helps reduce the risk of miscarriage.
  • Elevated Prolactin: prolactin is a reproductive hormone produced in the pituitary gland and plays a role in the development of the uterine lining. High levels of prolactin can impact the proper development of the lining.  If you have experienced recurrent miscarriage your doctor may prescribe medication to help manage your prolactin levels, although women are sometimes advised to stop the medication once pregnant.  Prolactin levels can be elevated by common stressors.  You can help reduce prolactin levels by tweaking your diet. Make sure your blood sugars are well managed – imbalanced blood sugars put more stress on the system. Also, focus on zinc-rich foods- turkey and beans are two examples.  Utilizing stress-reducing techniques (check out some of our mental health resources here), opting for regular, moderate exercise versus high-intensity, prolonged exercise sessions, and taking vitamin E and B-6 supplements are a few other areas to focus on.
Structural Issues

Issues with the uterus or cervix may lead to the inability to carry a pregnancy to term.  Some of these include:

  • Cervical insufficiency: the cervix dilates early in the pregnancy. This can be treated with cerclage, a stitch to the cervix (once you are pregnant) to help keep it closed until delivery.
  • Short cervix: the cervix is shorter than the average length and, in some cases, can lead to premature birth. This can also be treated with cerclage or in some cases progesterone supplements.
  • Septate uterus: the uterus is divided in half by a septum (band of tissue) and can lead to congenital abnormalities. This situation can be rectified via surgery to repair the uterus.
  • Fibroids: these are growths in the uterus that may impede blood flow to the baby. In some cases, these need to be removed to prevent future miscarriage.
  • Uterine scarring: like fibroids, these can impact the flow of blood to the baby and can also be removed through surgery.

More research needed

The impact of miscarriage is significant.  While the physical trauma is often acute, the psychological impact can be long term.  Research is ongoing to understand the causes of miscarriage and what can lead to multiple miscarriages.

more research needed on miscarriage

Here are some findings:

Drug Use

Recent research, presented at the 2019 American Society for Reproductive Medicine, (Barlow et al) looked at the impact of male marijuana use during the preconception period.  They found that couples with male partners who used marijuana more than once per week had a higher risk of spontaneous abortion (miscarriage) than those who used marijuana once a week or less.


Other studies have looked at caffeine intake and miscarriage.  A cohort study in the American Journal of Obstetrics and Gynecology looked at the association between caffeine consumption the risk of miscarriage and found a positive correlation.  High caffeine intake (over 200mg) per day increased the risk of miscarriage.

Nutrition and Miscarriage

Dietary intake is another area being investigated with respect to recurrent miscarriage.  A 2017 study in the International Journal of Fertility & Sterility looked at the nutrient consumption in relation to spontaneous abortion (miscarriage) before 14 weeks.  They found a correlation between poor nutrient intake and miscarriage.

There was a statistical difference between the two groups studied: those who experienced a miscarriage at or before 14 weeks pregnancy and those who were deemed healthy, pregnant women over 14 weeks.  The differences were in “servings/day of vegetables, bread and cereal, meat, poultry, fish, eggs, beans, fats, oils, and dairy products”.  However, we do not want this research to cause panic. These women didn’t just miss a serving of green vegetables.  They were lacking in folic acid, iron, vitamin C, vitamin B6, vitamin B12, and zinc.

What are the recommended levels?
Micronutrient Recommended Dietary Allowance (RDA) Examples What does it look like?
Folic Acid* 400-800 mcg Leafy green vegetables, citrus, beans, nuts 1 cup cooked spinach = 263 mcg

1 cup chickpeas (cooked from dry) = 282 mcg

*1 prenatal vitamin 400 mcg

Iron 8-18 mg Oysters, white beans, spinach 1 cup cooked quinoa = 2.8 mg

1 oz dark chocolate = 3.4 mg iron

Cooked beans = 2.5 mg

3 oz red meat = 3.5mg

1 baked potato = 2.1 mg

Vitamin C 75 – 90 mg Citrus, bell peppers, brussels sprouts, broccoli ½ Yellow bell pepper = 137 mg

1 cup chopped raw kale = 53 mg

1 kiwi = 71 mg

Vitamin B6 1.3 mg Fish, milk, carrots, potatoes 2 eggs = 0.13mg

1 sweet potato = 0.2mg

1 banana = 0.4mg

200g salmon = 0.8 mg

Vitamin B12 2.4 mcg Clams, fish, meat 6 oz Greek yogurt = 1.3 mcg

3 oz Trout = 5.4 mcg

1 egg = 0.5 mcg

Zinc 8-11 mg Oysters, crab, chickpeas, pumpkin seeds dark meat chicken (3oz) = 2.4 mg

oysters (3oz) = 74 mg

hemp seeds (3tbsp) = 4 mg

What should you eat?

Focus on whole foods and skip the processed ones – these are devoid of any nutritional value.  Go for variety.  You’ve heard “eating the rainbow”?  Incorporate different fruits and vegetables into your week.  Sneak veggies into smoothies and soups and healthy fat (think avocado and olive oil) can be easy to get – simply pop a handful of raw nuts and sprinkle unsweetened coconut flakes over your morning oatmeal. Spend a little time finding clean recipes that get you excited. Bland broccoli and boiled chicken wouldn’t do it for me either! A good rule of thumb is to include protein, healthy fat, and vegetables into each meal and scatter other foods like whole grains and dairy within your day.  If you need help we’ve created nutritional guides and meal plans to help you feel confident and in control of your choices.


Wrapping it up: what to do if you’ve suffered a recurrent miscarriage

If you have suffered recurrent miscarriages you have likely already spoken to your doctor.  If not, make an appointment to discuss your fertility and history of miscarriage.  You could discuss the following areas:

  • Progesterone supplements
  • Dietary changes
  • Caffeine consumption
  • Genetic testing
  • Carnitine supplementation
  • Prolactin level testing and options
  • Thyroid testing & presence of TAbs

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