Most Common Causes of Miscarriage

It can be very emotionally and physically draining to go through miscarriage. We have been there, we know. Luckily for us, we experienced it once, so I can only imagine how difficult it is to have recurrent miscarriages. In addition to the stress you and your body are going through, it is not possible to find out what caused the pregnancy loss, especially if it is your first miscarriage. The only explanation you will most likely hear from the doctors is that unfortunately it happens. Actually, 1 in 5 pregnancies end in miscarriage. It is very common. Some doctors would even say that it is for the best, since about 50% of all miscarriages occur due to fetal chromosomal abnormalities, and that it is the natural process of how the body deals with a “not perfect” embryo.

A lot of women would beat themselves up, thinking that they did something wrong and caused miscarriage. I had a list of things that I thought contributed to miscarriage. I was blaming myself for continuing to work out while pregnant and lifting weights. Even though I was doing lower intensity workouts and lifting lighter weights, I still thought that it caused miscarriage. Now, after talking to doctors and doing some research, I know that it was not my fault. If you had not exercised much before getting pregnant, and then suddenly started a very active lifestyle, then your body would be in a complete shock for sure. But when you continue with your lifestyle, but make sure you bring the intensity down a notch and listen to your body, then you should be fine. Unless your doctor or midwife recommends otherwise!

When we got pregnant for the second time, our doctor prescribed low-dose aspirin (81 mg) and progesterone capsules right away to prevent another miscarriage. She went through the list of most common causes of miscarriage with us, along with effective interventions in preventing an early pregnancy loss. And she explained why she ruled out some of the causes for me. I am going to share this list with you. I believe this will help you stop thinking that it was your fault, and it will also give you some knowledge of what may go wrong and why.

1. Genetic abnormalities

Chromosomal abnormalities in either an egg or sperm are the most common cause of miscarriage. And the risk of fetal chromosomal abnormalities increases with maternal age. As women get older, their eggs get older too and their quality decreases. Unfortunately, there is nothing anyone can do to prevent miscarriage in this case.

2. Blood coagulation defects

Women with antiphospholipid syndrome (APS) develop such conditions as venous or arterial thrombosis. This disorder increases the risk of blood clots in the blood vessels. Blood clots affect the flow of blood to the uterus and placenta. When you are trying to get pregnant, APS can cause fertility issues. And if you just got pregnant, it can cause pregnancy complications including thrombosis, fetal growth restriction, and fetal loss. Pregnant women with APS are treated with blood-thinning medicines like low-dose aspirin and/or heparin to prevent clotting problems and pregnancy loss. 

One of my co-workers had been trying to get pregnant for 3 years and had 1 miscarriage. Eventually, she found a doctor who found out she had a coagulation issue. She started the blood thinners and got pregnant 1 month after. She gave birth to a healthy baby girl a couple of months ago.

Due to significant changes that occur to the coagulation system during pregnancy, the test for APS antibodies may not be accurate. This was the reason our doctor put me on low-dose aspirin and advised to take in until the end of week 12. Just in case, so to say. My midwife recommended I keep taking it until the end of week 16 though. I might just do that, for my peace of mind!

3. Uterine anomalies

Uterine anomalies, such as uterine septum and polyps can be diagnosed with hysteroscopy or other imaging techniques. I had a hysteroscopy done a few months after the miscarriage to ensure there was no pregnancy tissue left prior to starting the IUI cycle. Everything looked good and the test did not identify any anomalies.

4. Low secretion of progesterone

Progesterone plays a very important role in the successful implantation of the egg in the uterus. When there is inadequate secretion of progesterone, the egg is not able to implant properly.

To prevent a miscarriage, doctors would prescribe progestogens at the beginning of the first trimester. Our doctor prescribed Prometrium progesterone capsules for me. I need to use them until the end of week 10.

5. Thyroid dysfunction

A thyroid panel test includes TSH, T3 and T4 hormones and can diagnose thyroid disorders. These thyroid hormones regulate the body’s metabolism and control how it uses energy. Normal thyroid function is necessary for fertility and healthy pregnancy. When thyroid hormones are not functioning normally, it can lead to an increased risk of miscarriage.

I had a TSH test a few days prior to our appointment. The results were good, so this risk was ruled out for me.

6. Polycystic ovary syndrome (PCOS)

Women with PCOS have an increased risk of miscarriage. Irregular menstruation or amenorrhea, excess of male hormone and anovulation make it very difficult to get pregnant. Miscarriage occurs in 30%-50% of women with PCOS, caused by elevated LH levels, insulin resistance, poor endometrial receptivity during implantation of an embryo, obesity, etc. There is so much information that it is hard to cover all the struggles women with PCOS go through in one paragraph. If you would like to know more, please refer to Google or Google Scholar

Unfortunately, it is often out of our control to prevent miscarriage. But what you can control is to take better care of yourself and your baby, and stay healthy. Watch your diet: try to eat a lot of fresh vegetables and fruit, drink enough water, reduce sugar intake and stay away from processed foods. Take your prenatal vitamins. Limit or completely give up caffeine. Stop smoking, consume alcohol and/or using drugs, if this was a part of your lifestyle before pregnancy.

Work on your mental health as well, it’s important to reduce the amount of stress. Learn how to meditate, if you have not been doing that already, do yoga, see a counselor or psychologist. Go for 30-40 minute walks every day. And stay positive no matter what. Your mindset plays a very important role in your pregnancy journey. You can do it!