What Causes Miscarriage

The most frequent and common cause of miscarriage is a problem with development. Extra or missing chromosomes 50% time are linked to this unfortunate event in some women’s pregnancies. Sometimes fetal demise occurs due to chromosomal issues. The remaining 25% of What Causes Miscarriage is due to “structural” problems with the fetus and placenta.

Table of Contents

What is a Miscarriage?

When you lose the baby in your womb, it is a miscarriage. It can happen during any stage of pregnancy, and sometimes there are no symptoms until after the baby’s birth.

The first stage of a miscarriage is often referred to as “breaking down,” which occurs during the first trimester. Miscarriage means that can terminate the pregnancy before the fetus is viable and big enough to survive outside the uterus.

The second stage is “fetal demise.” It can happen in the second or third trimester. The process of miscarriage is initiated by a chemical called prostaglandins, which are found in the lining of the uterus. When more prostaglandins are produced than can be used, the lining of the uterus becomes irritated and may start to break down.

Menstrual periods are more painful during the second trimester of pregnancy because your body breaks down the uterus lining. If the miscarriage continues, the cervix may soften, and the uterus may become empty. The opening to your uterus (cervix) becomes smaller, and the uterus walls are shed.

These processes are referred to as “menstruation.” Although this is a natural process, it can be excruciating. Tears in the uterus (ectopic pregnancy) or internal bleeding can cause severe pain.

The third stage of a miscarriage is “abortion.” Abortion begins after the fetus has been dead in the uterus for a while, and it can occur at any time after that. Symptoms may include vaginal bleeding, pelvic pain, a burning sensation, headaches, and diarrhea.

The placenta detaches from the uterus and falls out naturally a few days after the baby does. The fetus continues to grow inside the mother’s body in a condition known as “embryonic death.”

After a miscarriage, your cervix may look scuffed, and you may need a cervical exam to check for this. You may also be sexually active again after a miscarriage. The danger of complications after a miscarriage is less than 5%. Complications include heavy bleeding, uterine infection, and subsequent increased risk of miscarriage.

In the United States, miscarriages are most often due to chromosomal abnormalities.

Why Do Miscarriages Happen?

Chromosomal Abnormalities

The genetic material of cells is contained within chromosomes, and this genetic material is passed from parents to their offspring. Sometimes, there are errors in how this genetic material is given.

Chromosomal abnormalities can result from the error of genetic material during cell division in the development of an embryo, leading to an embryo with an extra or missing chromosome. Sex-linked genetic disorders are passed from the father to his children.

If a baby or child is born with a genetic disorder due to a father’s genetic abnormality, this is called a “transferred” genetic abnormality. Chromosomal abnormalities are the most common cause of miscarriage in 25% of miscarriages.

Thyroid Disorders

The thyroid, a small gland in the neck that produces thyroid hormones, is another common cause of miscarriage. The thyroid hormones are responsible for developing a baby’s physical structures in the embryo.

The thyroid hormones are produced in the gland and travel through the bloodstream to reach the uterus. If the levels of thyroid hormones are too low or too high, development may be adversely affected.

Diabetes

Miscarriages are more common in women with diabetes. The placenta of a woman with diabetes does not develop normally, which can cause many problems for the baby and miscarriage. Also, in a woman with diabetes, the blood vessels in the placenta may not develop properly.

Physical Complications

Miscarriage can have physical causes and chromosomal or structural causes. Infections of the uterus are a significant cause of miscarriage, and infections can cause a miscarriage if the infection damages the fetus. Physical problems that can lead to miscarriage include:

➢ Obesity

Obesity is a risk factor for many diseases, including cardiovascular disease and type 2 diabetes, and it also increases the risk of placental abruption. Obesity is linked to many pregnancy medical conditions, including gestational diabetes, high blood pressure, and placental abruption. Increased body weight is also associated with preterm birth, low birth weight, and intrauterine growth restriction.

Obesity increases the risk of having macrosomic babies, that is, babies that are too large to pass through the birth canal. A baby’s weight may be as high as the 95th percentile for gestational age, and this means that the baby’s weight is above the 95th percentile for babies born at the same gestational age. These babies are at a higher risk or danger of adverse outcomes, including miscarriage.

Obesity also interferes with prenatal care. Women who are obese tend to visit a doctor less often, miss more days of work or school, and do not receive the recommended number of prenatal care visits. Obesity is associated with higher rates of poor pregnancy outcomes, including miscarriage.

➢ Radiation

Prenatal exposure to radiation increases the risk for neural tube defects, such as spina bifida. Radiation exposure also has a direct relationship with miscarriage. The risk of miscarriage is 4% with doses of 2 to 5 Gray and 8% with 5 to 20 Gray amounts.

➢ Tobacco Smoke

Tobacco smoke contains many chemicals that can negatively affect a baby. These chemicals include carbon monoxide, cyanide, and polycyclic aromatic hydrocarbons. The fetus is particularly vulnerable to the harmful effects of tobacco smoke because the mother’s body already filters out much of the smoke.

The baby’s developing organs, such as the lungs and heart, are also more sensitive to harmful chemicals in tobacco smoke. The mother’s smoking can also lead to low birth weight, preterm birth, and sudden infant death.

➢ Alcohol

A small amount of alcohol consumption can increase the diameter of blood vessels. However, heavy or binge drinking can have the opposite effect, resulting in blood vessels that are less capable of carrying blood, leading to several problems, including miscarriage.

Pregnancy is a period of increased demand for blood, and if there is a reduced blood supply, miscarriage is more likely to occur. A small number of studies have discovered that alcohol use during pregnancy also increases the risk for poor fetal outcomes, including fetal death and fetal malformations.

Blood Clotting Disorders

Blood clotting disorders increase the risk of miscarriage. About 1 in 125 pregnancies is complicated by abnormal blood clotting. It is more common in those who:

✔Deficiency of antithrombin (AT)

✔Factor V Leiden (VFL)

✔Prothrombin G20210A (PTG)

✔Other hereditary causes.

Hormonal Imbalances

The sex hormones estrogen and progesterone of a woman have a vital role in the early development of a pregnancy. They also directly affect the uterus tissues where the pregnancy resides. The hormones are responsible for preparing the uterus for pregnancy. Endocrine disorders can cause some medical conditions, including miscarriage.

For example, high thyroid-stimulating hormone (TSH) levels can cause a miscarriage, and the TSH levels can stay elevated for months after the pregnancy has been lost. This condition, known as postpartum thyroiditis, is caused by the body’s immune system attacking the thyroid gland.

Immunological Disorders and Chronic Illness

Women who have had a previous miscarriage are prone and more likely to have a subsequent miscarriage. Immunological disorders such as lupus, scleroderma, and sarcoidosis increase the risk of miscarriage, which may be due to several different mechanisms.

It is possible that a woman’s immune system changes in response to an embryo, becoming less capable of preventing an attack from the mother’s immune system.

Alternatively, there may be a direct effect of the chronic illness or medication a woman is taking, such as the immune-suppressive effects of cancer chemotherapy.

What are the Symptoms of a Miscarriage?

➭ Bleeding that Progresses from Light to Heavy

Heavy bleeding is the most common cause of miscarriage. Heavy bleeding may be accompanied by vaginal bleeding, bleeding from the bowel, or bleeding from the vagina. The bleeding may be between 6 and 24 hours after intercourse.

Between 10 and 20% of women have no bleeding at all. A few days after the start of bleeding, you might experience some cramping, and you may also have a burning sensation with urination.

➭ Cramps

Cramps may be felt in the lower abdomen. They typically get worse with activity and generally last for 2 to 4 hours. While they are not usually severe enough to require medical attention, they can become quite painful and disrupt sleep.

➭ Abdominal Pain

This pain is sharp and constant, and it intensifies with pressure. It is best described as a dull, gnawing pain. It is located between your belly button and your anus, and it may occasionally move to the upper stomach or back.

➭ Low Backache that may Range from Mild to Severe

The low backache may be due to pressure on the nerves that originate here. It may be described as a dull, throbbing pain that is constant. The pain may move down the leg and into the foot.

Miscarriage Risk Factors

➭ Age

The risk of miscarriage increases with your age. Generally, a woman’s chances of miscarrying increase by 1% per year of her age. Miscarriage is more likely to occur in those who meet the following criteria:

Older than 40
Have had one previous pregnancy miscarriage
Have a history of miscarriage in a previous pregnancy
Have certain chronic illnesses
Take certain medications
Are exposed to certain environmental factors

➭ Previous miscarriages

It is estimated that up to 30% of all miscarriages are due to chromosomal abnormalities. These abnormalities are present in the embryo or fetus and result in a miscarriage by the natural process of miscarriage. If the mother had a similar abnormality in a previous pregnancy, there is a greater chance of a second miscarriage. Up to half of all miscarriages occur in a child whose mother had a previous miscarriage.

➭ Uterine or Cervical Problems

Problems with the fetus’ umbilical cord can lead to a miscarriage. If the cord develops abnormally or becomes torn, blood can leak into the space between the mother’s womb lining and her cervix.

➭ Smoking, Alcohol, and Illicit Drugs

Smoking, excessive alcohol, and drug use can interfere with a pregnancy. Each of these substances can directly affect the health of a fetus, and it can also affect the mother’s health.

➭ Weight

Being overweight or obese is a well-known danger risk factor for poor pregnancy outcomes. It’s associated with higher rates of miscarriage and fetal death, and problems such as gestational diabetes and high blood pressure.

➭ Invasive Prenatal Tests

In the early stages of a pregnancy, a blood test called a nuchal translucency test can check the thickness of the fetus’ neck. If the thickness is greater than 0.5 millimeters, there is a higher chance of having a baby with abnormalities such as spina bifida.

An ultrasound can also check for problems. An ultrasound is recommended as a first-trimester screen after 13 weeks of gestation. It can look for multiple abnormalities, allowing better assessing the chances of having a baby with a disability.

Complications

➭ Fever

The fever may be a sign of some pregnancy-related conditions. Infections are a common cause of fever during pregnancy, and the most common infection causing a fever is bacterial. Viral and parasitic infections such as influenza, measles, and toxoplasmosis are less common causes.

While any change in a woman’s temperature warrants medical attention, a fever of 38.3 celsius or higher is generally considered a medical emergency.

➭ Chills

Chills Pregnancy can present with chills, a sign of either a viral infection or a temperature below 38.3 celsius. Chills are caused by the immune system’s response to cold, not a decrease in core body temperature.

Pregnancy is a condition where the immune system is suppressed, so the risk of serious complications is low. However, women should avoid exposure to cold, especially in the days before the expected period.

➭ Lower Abdominal Tenderness

Abdominal pain in early pregnancy is usually not a cause for concern. However, further testing may be needed if your pain is not relieved by rest and is accompanied by lower abdominal tenderness. The doctor may want to take a urine sample to test for infection. They may also do a fetal fibronectin or a human chorionic gonadotropin (hCG) test to look for a miscarriage.

➭ Foul-smelling Vaginal Discharge

Foul-smelling vaginal discharge typically occurs around the 12th week of pregnancy, and it is not a cause for concern, but it may signify an infection. If you have any questions about your discharge’s color, smell, or taste, contact your doctor.

Prevention

➭ Seek Regular Prenatal Care

Prevention is the best way to decrease the chances of having a miscarriage. A woman should go to her doctor for regular checkups, for which a variety of tests are done. Your doctor can screen for risk factors, identify any problems, and provide recommendations for lifestyle changes to decrease your chance of having a miscarriage

➭ Avoid known Miscarriage Risk Factors (Smoking, Drinking Alcohol, and Illicit Drug Use)

Being overweight or obese and over 35 has been linked to an increased risk of miscarriage, and women who smoke also have an increased danger risk of miscarriage. Similarly, women with a history of previous miscarriages are at increased risk for subsequent miscarriages. Taking certain medications can also put the baby at risk. Always follow the dosing instructions your doctor gives you.

➭ Take a Daily Multivitamin

Daily multivitamins are beneficial during pregnancy. However, research has found that not one multivitamin is better than others. You will need to talk to your doctor about the safest option for you.

➭ Limit your Caffeine Intake

Too much caffeine can increase the risk of miscarriage. Caffeine contains a chemical called xanthine that can interfere with fetal development. For this reason, the doctor may advise that you decrease your caffeine intake.

Final Thought What Causes Miscarriage

The exact cause of miscarriage is often unknown, and risk factors include age, medications, previous miscarriages, and certain infections. In most cases, a woman’s body will naturally expel the fetus once it is no longer necessary. In this way, miscarriage is often a natural part of a woman’s reproductive cycle.