15 Truths Behind Why Women Miscarry

A miscarriage is the loss of a baby before the 20th week of pregnancy. According to the March of Dimes, up to 50% of all pregnancies end in miscarriage. A lot of times, miscarriages happen before a woman misses a menstrual period or even realizes she is pregnant. Of women who have confirmed a pregnancy, 15-25% may end in a miscarriage. More than 80% of miscarriages occur within the first three months of pregnancy. Miscarriages are less likely to occur after 20 weeks, but they can happen; these are called late miscarriages.

If a woman experiences the symptoms listed above, she should contact her doctor right away. The doctor may suggest coming into the office or going straight to the emergency room.

Most miscarriages happen because the baby has some sort of genetic problem or defect. Other causes of miscarriage may include:

Infection Maternal medical conditions Maternal physical problems Hormone imbalances Uterine problems

In addition, a woman has a higher risk of miscarrying if she is over the age of 35, has certain diseases such as diabetes or thyroid problems, or has had a history of previous miscarriages. Controlling any diseases or managing any health issues before conception may lead to a healthier pregnancy.

It’s important to see a doctor regularly during pregnancy to monitor the baby’s growth and development. Although miscarriages can be devastating, there are tests and treatments available that can help women have a healthy pregnancy – and a healthy baby – in the future.

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15 Chromosomal Abnormalities

It is a blood test to determine problems with the baby in the mother's womb, less invasive than taking amniotic fluid.[/caption]

Many miscarriages happen spontaneously due to a chromosomal abnormality, such as Down syndrome, cystic fibrosis, or Turner syndrome. A lot of times, if there is any problem with the chromosomes, the developing system knows to shut itself down.

Chromosomes are the tiny structures in every cell that carry our genes. We each have 23 pairs of them, one set from our mother and one set from our father. One of the most common reasons that a miscarriage occurs is because of a problem with an egg or sperm’s chromosomes during the formation of the embryo. Sometimes, when an egg and sperm meet, one or the other is defective and the chromosomes can’t match up properly. As a result, the embryo develops abnormally, and often, the pregnancy ends in a miscarriage. If a couple experiences two or more recurring miscarriages, they may undergo medical testing and learn that they have may have chromosomal abnormalities that don’t affect them, but do affect a pregnancy from properly developing.

14 Uterine Abnormalities

If you have a uterus that is shaped abnormally (or divided) a miscarriage can occur because the embryo either can’t implant or once it does, it can’t get the nourishment it needs to grow and develop. If the uterus is divided, or has an extra piece of tissue called a septum, it can lead to miscarriage because that piece of tissue doesn’t have the same blood supply as the rest of the uterus. If an embryo were to try to implant itself on that septum, it would lead to miscarriage. It is possible to have surgery to correct these abnormalities, and afterwards, the chances of having a healthy pregnancy are high.

Other non-genetic abnormalities, like uterine fibroids, can develop over time. Fibroids are benign (non-cancerous) tumors that develop in the uterine cavity. Not only can they cause miscarriages, but they can also impact the success of IVF. Fibroids can be detected during a pelvic exam, through ultrasound or an MRI, and can be removed through surgery.

13 Incompetent Cervix

A weakened or incompetent cervix (also known as cervical insufficiency) is another problem that can lead to miscarriage, because toward the end of the first trimester the fetus has grown large enough that the cervix starts to bulge. If the cervix is weakened, it can’t hold the fetus in.

There are usually some symptoms before a miscarriage caused by cervical insufficiency. A woman may feel sudden pressure and her water may even break. Tissue from the fetus and placenta may be expelled without much pain.

An incompetent cervix can be treated with a procedure called a cerclage, where the cervix is stitched closed. Many women who are diagnosed with an incompetent cervix may also be placed on bed rest for part of their pregnancy in addition to having the cerclage procedure. The stitch keeps the cervix closed and is removed around the time of delivery. The stitch can be placed before a miscarriage occurs, if the cervical insufficiency is discovered in time.

12 Immunologic Disorders

If you think about it, the fact that a woman’s body views sperm as a foreign object, it’s amazing that pregnancy can happen at all. Most of the time, an egg is fertilized and sends messages to the body indicating that everything is all right, and the pregnancy develops normally. However, in some cases, the embryo isn’t accepted by the woman’s body and is attacked by those antibodies. For some reason, the body just does not accept the pregnancy, and the pregnancy ends in a miscarriage.

There is still a lot to be discovered about immunological disorders and their role in contributing to miscarriage. While the topic is up for debate, the American College of Obstetricians and Gynecologists believes that certain autoimmune disorders must play a role in some miscarriages, especially when a mother has recurring miscarriages.

Some women with immunological disorders have had successful pregnancies after undergoing treatments with aspirin, blood thinners, and certain steroids.


Polycystic ovarian syndrome (PCOS for short) is one of the leading causes of female infertility because it causes irregular ovulation and menstruation. Unfortunately, a PCOS pregnancy also faces a higher rate of complications, including miscarriage. Although researchers are unsure of the exact connection, it appears that hormonal irregularities caused by PCOS can in turn cause a miscarriage.

Pregnant women with PCOS might have elevated levels of insulin that can interfere with blood clotting and the breakdown of clots. High insulin levels can result in increased blood clotting in the uterine lining and the placenta, which can lead to placental insufficiency, or the failure of the placenta to supply nutrients to the developing fetus. As a result, miscarriage can occur.

Fortunately, women struggling with infertility due to PCOS can improve their chances of a successful pregnancy by taking care of their health. Eating a nutritious diet, maintaining a regular exercise routine, and taking nutritional supplements can help lower the risk of complications during pregnancy. In addition, treatment with oral antidiabetic drugs, such as metformin, can be successful in reducing the risk of miscarriage in women who have PCOS.

10 Infections

It’s true that we have bacteria in our bodies that can help us, but certain bacteria can cause problems, including an increased risk of miscarriage. In women, infection with certain bacteria can inflame the endometrium (the lining of the uterus) which makes it impossible for the embryo to implant and develop. Some of these infections that occur in the lining of the uterus have no symptoms, but can lead to miscarriage.

These infections can be caused by fluctuations in the amount of bacteria present, or changes in acidity that can cause an explosion in the growth of bacteria present. Women who have had several gynecologic procedures are more at risk for these types of infection.

If your doctor believes you have an infection, he or she may do a biopsy of the lining of the uterus, or may even treat the condition as though it exists, just to be safe.

9 Blood Clotting Disorders

Although they are rare, miscarriages can result from thrombophilias, or blood clotting disorders, such as Factor V Leiden. Thrombophilias that are inherited have not been shown to cause miscarriages during pregnancy, but those that are acquired, on the other hand, can.

The Factor V Leiden gene mutation is associated with a slightly increased risk of miscarriage, and  women with this mutation are more likely to have recurrent miscarriages. Some research suggests that Factor V Leiden may also increase the risk for other complications during pregnancy, such as preeclampsia, slow fetal growth, and placental abruption. However, the association between these complications and Factor V Leiden has not been confirmed. Many women with Factor V Leiden have healthy, uneventful pregnancies.

Many women don’t even know they have disorders like these until they’re screened. Screening can be done as part of preconception planning, or can take place after experiencing a miscarriage. If a woman is diagnosed with a blood clotting disorder, blood thinners may help improve her chances of having a successful pregnancy.

8 Thyroid Disorders

The thyroid is the butterfly-shaped gland in the front of the neck that secretes thyroid hormones. The thyroid gland is like the command center of the body, doing everything from regulating your metabolism to making sure your organs run properly. It’s also important for reproductive function, in that it can affect egg production and the development of the fetus.

Thyroid conditions can make the uterus an unfavorable environment for embryos to implant and survive. Whether it be hypothyroidism (thyroid levels too low) or hyperthyroidism (thyroid levels too high) disorders of the thyroid can cause problems with infertility or cause recurring miscarriages.

It is thought that if a woman’s thyroid function is low, her body will overcompensate by producing hormones that can actually suppress ovulation, making it harder to conceive. If a woman’s thyroid is producing too many hormones, it can interfere with estrogen’s ability to make the uterus suitable for implantation.

Autoimmune thyroid disease can also be a cause of miscarriage. Thyroid antibodies, which develop when the immune system fights thyroid-specific proteins, have been shown to increase the risk of miscarriages and stillbirths, as well as premature birth and low birth weight.

7 Lifestyle Risks

You don’t need us to tell you that smoking is bad for you, especially when you’re pregnant, do you? Well, just in case you need a reminder… Lifestyle habits such as smoking, drug abuse, and drinking during pregnancy can all lead to pregnancy complications and miscarriage.

What if you had a glass or two of wine before you found out you were pregnant? Don’t freak out, this likely won’t hurt anything. It’s when a developing fetus is exposed to large amounts of these chemicals on a regular basis that can lead to miscarriage. Nicotine from cigarettes crosses the placenta and can interfere with blood supply to and growth of the fetus. Drinking two or more alcoholic beverages a day is also associated with a higher risk of miscarriage.

If you have any concerns at all about whether or not you can have a healthy pregnancy, it’s a good idea to give up these bad habits before you even conceive.

6 Excessive Caffeine Intake

A recent study by Kaiser Permanente in the American Journal of Obstetrics and Gynecology showed that women who consumed 200 milligrams or more of caffeine a day (about two cups of coffee or five 12-ounce cans of soda) have twice the miscarriage risk of women who didn’t have any.

It’s not exactly understood why, but researchers believe that caffeine crosses the placenta and can affect the developing embryo. While one cup of coffee or soda a day is probably fine, many doctors think that it's a good idea to consider being extra safe and switching to decaf while you’re trying to conceive and during your pregnancy. However, other studies have shown that perhaps caffeine isn’t so dangerous after all. Some doctors say that up to four cups of coffee a day is safe for women in all stages of pregnancy.

But with so many risk factors out there that are out of your control, cutting back on caffeine is one simple thing that you can do that might improve your baby’s health.

5 Diabetes

When it comes to diabetes, it’s mostly uncontrolled diabetes that causes a miscarriage. Since the entire body runs on glucose, insulin is crucial to maintaining the function of all the system of the body. Poorly controlled blood sugar can lead to pregnancy complications for both mother and baby.

Some possible complications include:

High blood pressure. High blood pressure during pregnancy can lead to intrauterine growth restriction, stillbirth, and possibly preterm labor and delivery.

Birth defects. Babies born to women with diabetes have a higher risk of developing congenital abnormalities, such as heart defects and neural tube defects.

Elevated birth weight. When a newborn weighs more than 9 pounds, 4 ounces (or above the 90th percentile for expected size/gestational age) it is called macrosomia. Larger babies are at risk for delivery complications and may need to be delivered via c-section.

Preterm labor. Diabetic women are at risk for preterm delivery. Infants born before 37 weeks are at risk for feeding and breathing difficulties and long-term medical conditions.

Miscarriage and stillbirth. Diabetic women are at an increased risk for miscarriage. While women with diabetes also have an increased risk of having a stillborn, taking care to monitor and maintain control of blood sugar levels can greatly reduce this risk.

4 Chronic Medical Conditions

Chronic illnesses and medical conditions such as blood clotting disorders, thyroid disease and diabetes can increase your miscarriage risk. Autoimmune diseases, such as lupus, can also negatively impact your pregnancy. That doesn’t necessarily mean that if you have one of these illnesses that you can’t have a healthy pregnancy and deliver a healthy baby, but you do need to understand the possibility of risks and complications, including miscarriage.

Women with lupus are at a higher risk of pregnancy complications and miscarriage because lupus can cause health problems such as kidney disease, high blood pressure, and antibodies that may increase the likelihood of a miscarriage.

Lupus anticoagulants are antibodies that are directed against clotting proteins found in the blood. These antibodies may cause blood clots in the lung or legs, stroke or heart attack, or, for a woman who is trying to conceive – repeated miscarriages. Studies have shown that testing positive for lupus anticoagulant antibodies in the first trimester of pregnancy is a strong predictor of miscarriage risk in women with lupus.

3 Hormonal Imbalances

Hormones are responsible for everything from ovulation to menstruation to conception. Sometimes a woman’s body produces too much of certain hormones, or sometimes it doesn’t produce enough. Having hormonal imbalances can make it difficult for a woman to conceive or to have a healthy pregnancy.

Sometimes a woman's body doesn't release enough of the hormone progesterone, which is necessary to prepare the uterine lining to support the developing embryo and placenta. In addition, a high level of prolactin can also disrupt the development of the uterine lining. Low progesterone levels in the second half of the menstrual cycle, known as luteal phase defect, can cause problems with implantation. If the egg is able to implant in the uterus, but there is not enough progesterone during the first 10-12 weeks of gestation, the pregnancy may terminate.

Symptoms of luteal phase defect may include frequent periods, spotting between periods, trouble getting pregnant, and miscarriage. It may be hard for a doctor to diagnose luteal phase defect because there’s no simple test for it, but he or she may suggest testing your follicle-stimulating hormone (FSH), luteinizing hormone (LH) and progesterone levels.

2 Sperm DNA Fragmentation

A cause for miscarriage that is often overlooked, but also thought to be very common, is known as sperm DNA fragmentation. This happens when strands of sperm DNA are broken and unable to deliver complete DNA to the egg. Although there are different degrees of severity, the likelihood is two to five times higher for men that have the condition, compared to those with healthy swimmers.

There are lots of reasons why sperm DNA fragmentation occurs, including smoking, the use of antidepressants, exposure to heat, chemotheraphy, adiation, or even a fever.

Treatment for sperm DNA fragmentation depends on the patient or what’s causing it. Some men may need to stop a medication, take antioxidant supplements, or have a procedure known as sperm aspiration and intracytoplasmic sperm injection. It’s also possible that the egg can potentially repair DNA damage in a defective sperm, although it depends on how much and where the damage is located.

1 What Puts You At Higher Risk

Women patient in hospital ill euthanasia health female Credit: Fotolia

It’s possible that any woman can have a miscarriage. However, some are more likely to miscarry than others. Here are some risk factors that may increase the likelihood of having a miscarriage.

Age: Older women are more likely to conceive a baby with a chromosomal abnormality, and miscarry as a result. Your risk of miscarriage also gets higher with every child you carry.

History: Women who have had two or more miscarriages in a row are more likely to have another miscarriage.

Chronic diseases: Poorly controlled diabetes and certain blood clotting disorders, autoimmune disorders, and hormonal disorders are conditions that can all increase the likelihood of miscarriage.

Physical problems: Having congenital uterine abnormalities, severe uterine adhesions, or cervical insufficiency can all lead to a miscarriage. It’s also possible that there is a link between uterine fibroids and miscarriage, but most fibroids don’t cause any problems.

History: If you, your partner, or family members have a genetic abnormality, if you have had one identified in a previous pregnancy, or if you have already given birth to a child with a birth defect, you’re at a higher risk for miscarrying.

Your risk of miscarriage is also higher if you conceive again within three months after giving birth.

Sources: Parenting, Parents, WebMD, Baby Center

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