What causes miscarriages?

Although many women experience at least one interruption of pregnancy, often the specific cause is never known. Some of the conditions that can cause, or increase the risks of, miscarriages are:

• Miscarriages are very commonly caused by defects in the baby's genetic code. Sometimes the defects are bad enough to make life and further development impossible. This is what usually causes the very early term miscarriages.
  
  
• The hormone levels that are necessary for pregnancy can be imbalanced. Sometimes it is because the baby is not producing enough of his or her own hormone, or it can be that the mother's hormone levels are off. Around 10-12 weeks the placenta takes over from the ovary in producing the hormone to maintain the pregnancy and sometimes this changeover does not happen correctly or fully.
  
  
• There may be physical problems with the mother's cervix, the most common is called "incompetent cervix". Incompetent cervix (in the late second trimester) may allow the cervix to dilate, causing a late miscarriage or a very premature labor. A small surgical procedure can sometimes be done to help fix this problem to allow the baby time to develop appropriately.
  
  
• Problems with the structure of the uterus (such as a T-shaped uterus), or fibroid cysts in the uterus can cause the pregnancy to fail.
  
  
• Using cocaine, alcohol, smoking cigarettes, or other drug use can cause a higher chance of miscarrying a baby. High caffeine intake may also contribute to miscarriages.
  
  
• Exposure to dangerous toxic chemicals, such as benzene, arsenic, or formaldehyde, before or during pregnancy can be dangerous and cause abortion. High levels of mercury can contribute, however there is a myth that the mercury in your teeth fillings and chewing gum could cause loss of the pregnancy, which is incorrect. The mercury levels would need to be much greater than that amount to cause such an effect.
  
  
• Non-steroidal anti-inflammatory drug (NSAID) use (such as ibuprofen or naproxen) at the time of conception or during early pregnancy may have an effect.
  
  
• A snakebite can cause a miscarriage.
  

 

• There are medical conditions and disorders such as poorly controlled chronic underlying diabetes; autoimmune diseases, like Lupus Erythematosus; and a blood-clotting disorder called antiphospholipid antibody syndrome as other examples of potential causes.
  
  
• Or it can happen if there are certain bacterial or viral infections, sexually transmitted diseases, or other infections complicating the pregnancy. (see link below for a link to information about specific infections that seem associated with miscarriages)

 

• There is a blood incompatibility problem that makes the mother's body have an "allergic response" to the fetus. When the Rh Factor of the mother's blood is different from the Rh Factor of the father, and if the baby inherits the father's Rh positive condition, the mother's body doesn't recognize the baby's blood as something that belongs there and so it "attacks" like it is a foreign substance, this can cause damage to the fetus that causes a miscarriage.

• Extreme trauma, such as from a violent auto accident, with direct and extremely hard blows to the mother's abdomen can cause damage to either the mother or the baby and the pregnancy may abort as a result. The baby is usually well protected from falls or other blows to the mother's abdomen, so it would normally only occur with extreme trauma.
  
  
• When the mother's age is 35 and older, or the father's age is beyond age 35, there can be problems with genetics or other factors that contribute to higher risks of miscarriage.
  
  
• A history of a pregnancy with a birth defect, or a history of recurrent miscarriages (three or more) makes one at much higher risk for additional losses. A history of miscarriages on the mother's side of the family can also be an indicator of potential problems.
  
  
• Multiple birth pregnancies (i.e., twins, quads, etc. ) have a higher risk of miscarriages.

 

Factors that do not contribute to miscarriages, contrary to myth and wives' tales:

No normal activities you do will cause a miscarriage, and when you have regular prenatal care and follow the Obstetrician's directions, you should not believe it is your fault if it happens . A miscarriage is nature's way of dealing with problems with the development of the baby or with the mother's body's ability to support the pregnancy. When you think how complicated it all is, it is amazing that it goes right so often.

• Miscarriages are not caused by the mother's emotional state, emotional distress, loss of a loved one, or sudden frightening experiences.
  
  
• Sexual intercourse during pregnancy can not cause this type of problem.
  
  
• Exercise, jogging, working, or moderately heavy lifting are not contributing factors.
  
  
• A single diagnostic X-ray (or total radiation exposure of less than 5 rad) will not produce miscarriages (if you are worried about this or other diagnostic tests, discuss it with your radiologist or a health professional).
  
  
• Falling or hitting the abdomen, unless very severe trauma as in auto accidents.

• Dietary factors, there is no conclusive evidence that a diet moderately lacking in nutrients causes miscarriage. Also, the nausea and vomiting (morning sickness) of early pregnancy will not cause miscarriage.

• There had been some concern that high folic acid (Vitamin B9) intake may have been a factor, but research has now shown that it may actually help prevent miscarriage.
  
  
• Exposure to computer monitors, the use of electric blankets or heated water beds are not contributors to miscarriages.
  

More information:
Be aware that if it is going to happen, there is no real way to prevent a miscarriage from occurring without medical help. For this reason, it is very important to have prenatal care and regular check ups beginning as soon as you know you are pregnant.

You can have a miscarriage and not even know it, because, according to how far along you are and especially in the early part of a pregnancy, the embryo or fetus can pass through in what seems like just a heavy menstrual flow, sometimes with perhaps some clots.

If you have what seems like a miscarriage, even if in the earliest part of the pregnancy, it is important for you to see a medical professional right away due to the possibility of uncontrolled bleeding or fetal/placental tissue remains that need to be removed by a doctor.