Causes of Miscarriage

There are quite a lot different triggers for miscarriage. Medical conditions including the mom may raise risk, as can the occurrence of chromosomal abnormalities in the baby.

Lifestyle factors can play a role. Some of these are avoidable, such as smoking, whereas others are not, such as increased stress associated to circumstances beyond our control. With a few of these categories of risk factors, there is overlap. For example, chromosomal (hereditary) abnormalities in the baby are related to an increased of miscarriage, however chromosomal abnormalities are, in turn, associated with increased maternal age.

Here are most common causes of miscarriage according on worldwide statistics and facts.

Mother’s Age

The risk of miscarriage differs considerably with a woman’s age, shows a strong pattern of recurrence, and is increased after some pregnancy complications, discovers a study from Norway published in The BMJ today.

So a team of scientists, led by Maria Magnus at the Norwegian Institute of Public Health, set out to estimate the risk of miscarriage among Norwegian women and to examine the association with age and pregnancy history. Risk of miscarriage was estimated according to the woman’s age and pregnancy history, considering caused abortions.

There were 421,201 pregnancies during the research study period. After representing caused abortions, the general miscarriage rate was 12.8%. The risk of miscarriage was least expensive among women aged 25-29 (10%), and rose quickly after age 30, reaching 53% among women age 45 years and over. There was likewise a strong recurrence risk of miscarriage. After one miscarriage, the risk of another was increased by half, after 2, the risk doubled, and after 3 consecutive miscarriages, the risk was 4 times higher.

Here it is necessary to understand that the age that can be normal for pregnancy in women of one nation is critical for another. For example, women who come from warm climates Mature physically faster than Northern women. The indicator here is quite obvious: how early menstruation begins in a girl. Therefore, the hysteria of the citizens of the Northern peoples about the timing of marriage in countries where women Mature earlier is quite strange.

Previous Miscarriages

Women who have had 2 or more consecutive miscarriages are at greater risk of miscarriage. The majority of the problems that trigger miscarriage take place by opportunity and are not most likely to occur again. One miscarriage does not substantially increase the risk of the exact same thing occurring with your next pregnancy, as long as no particular cause has been found. Testing is not typically offered to women who have miscarried as soon as or two times because it is very not likely that anything would be found.

Smoking, Alcohol and Illicit Drugs

When a woman smokes cigarettes during pregnancy, her fetus is exposed to numerous hazardous chemicals. Nicotine is only one of 4,000 toxic chemicals that can pass from a pregnant woman to her fetus. Nicotine triggers blood vessels to narrow, so less oxygen and less nutrients reach the fetus. Nicotine likewise damages a fetus’s brain and lungs. This damage is long-term.

Alcohol can interfere with the normal growth of a fetus and trigger birth defects. When a woman drinks throughout pregnancy, her fetus can develop long-lasting issues. The most serious disorder is fetal alcohol syndrome (FAS). FAS can cause growth issues, psychological disability, behavioral issues, and unusual facial functions.

Various drugs may affect the fetus in various methods. Utilizing illegal drugs early in pregnancy can cause abnormality and miscarriage. Throughout the later weeks of pregnancy, illegal drug use can disrupt the growth of the fetus and trigger preterm birth and fetal death.

Pregnancy After Infertility

You might have conceived after many years of attempting and/or fertility treatment, and after that miscarried or had an ectopic or molar pregnancy. You might feel that this is even worse than not conceiving, as the happiness of ending up being pregnant was followed by the distress of loss. Although some reasons for infertility might likewise immediately place a pregnancy at high-risk, infertility itself does not rule out a low-risk pregnancy.


Overweight women are more likely to miscarry a healthy baby, according to research study including 204 women who had actually suffered a miscarriage. According to The Guardian, the scientists said the findings support recommendations that obese women ought to drop weight prior to attempting to conceive. The excess miscarriage rate in overweight and obese women is because of the loss of chromosomally normal embryos. It’s essential to identify elevated BMI (body mass index) as a risk factor for miscarriage and counsel those women who are affected on the importance of lifestyle modification.


According to BBC, underweight women were 72% more likely to miscarry in the first trimester, they discovered. However the two-thirds of women who took vitamin supplements during early pregnancy reduced their threat by around 50%. The impact was most pronounced amongst those taking folic acid or iron and multivitamins consisting of these. Women who are very underweight prior to they end up being pregnant are 72% more likely to miscarry in the first 3 months of pregnancy, a study suggests.

Physical Complications

Less typical, but still substantial events of miscarriage can be caused by physical issues with the mother, such as uterine abnormalities including septum or polyps, or cervical incompetence. In numerous instances, losses as a result of a physical problem will occur in the second or third trimesters.

Hypothyroidism or Hyperthyroidism

Research study suggests that having an underactive thyroid might be connected with some kinds of pregnancy loss. A 2000 study discovered that women with neglected thyroid deficiency had actually a considerably increased threat of second-trimester miscarriage or stillbirth. A various study in 2005 found that subclinical hypothyroidism (SCH) might indicate an increased risk of placental abruption and preterm shipment, both of which can result in later pregnancy loss. The proof is less clear about a link between hypothyroidism and first-trimester miscarriage. Some studies suggest that thyroid autoimmunity (TAI) might be connected to first-trimester miscarriage, however other research studies contradict the link and the matter is still up for dispute.

Hyperthyroidism, if neglected, can cause stillbirth, early birth, or low birth weight for the baby. Often it results in fetal tachycardia, which is an abnormally quick pulse in the fetus. Women with Graves’ disease have antibodies that stimulate their thyroid gland. These antibodies can cross the placenta and stimulate a baby’s thyroid gland. If antibody levels are high enough, the baby might establish fetal hyperthyroidism, or neonatal hyperthyroidism. A woman with hyperthyroidism while pregnant is at an increased risk for experiencing any of the symptoms and signs of hyperthyroidism. And unless the condition is moderate, if it is not dealt with quickly a woman might miscarry throughout the first trimester; develop congestive heart failure, preeclampsia, or anemia; and, seldom, develop a severe type of hyperthyroidism called thyroid storm, which can be life threatening.

Chromosomal Abnormalities

Miscarriages brought on by chromosomal abnormalities have actually been found to happen more frequently in women older than age 35. This is because the all the eggs that a woman will ever have she has from birth and the eggs age with her. Paternal age might also similarly play a role. The frequency of miscarriage in women below age 20 is around 12 to 15 percent and functions as the woman approaches age 40. There is nothing that can be done to prevent miscarriage due to a chromosomal abnormality and when a miscarriage has actually begun there is nothing one can do to stop it.


Given that the whole body is sustained by glucose, insulin is essential to appropriate functioning of all body systems. Inadequately managed blood sugar can increase of a danger for miscarriage. High blood sugar levels early in the pregnancy (prior to 13 weeks) can trigger abnormality. They also can increase the risks of miscarriage and diabetes-related problems. However many women don’t understand they’re pregnant until the baby has actually been growing for 2 to 4 weeks. That’s why you need to have good control of your blood sugar before you start attempting to conceive.

Blood Clots

Like physical abnormalities, miscarriages that arise from blood clotting disorders (such as Factor V Leiden), are more unusual, but they do occur. However they’re just not as common as the other reasons.

The usual symptoms of miscarriage are vaginal bleeding and lower tummy (abdominal) cramps. You might then pass something from the vagina, which often looks like a blood embolism or embolisms. In most cases, the bleeding then slowly settles. The time it considers the bleeding to settle varies. It is typically a few days however can last two weeks or more. For the majority of women, the bleeding is heavy with embolisms but not extreme – it is more like a heavy period. However, the bleeding can be extremely heavy sometimes.

Immunological Disorders

Immunological disorders are an extensively disputed topic among women’s healthcare providers, primarily because there is still much to be found about their function in contributing to miscarriage. Nevertheless, the American College of Obstetricians and Gynecologists agrees that specific autoimmune disorders do play a function in miscarriage, particularly with persistent miscarriages. There are many kinds of autoimmune and autoimmune-related disorders that might cause miscarriage. A few of the most common are:

  • Systemic Lupus
  • Crohn’s Disease
  • Rheumatoid Arthritis
  • Scleroderma
  • Addison’s disease
  • Celiac disease
  • Grave’s disease
  • Multiple Sclerosis
  • Reactive arthritis
  • Pernicious anemia
  • Hashimoto’s thyroiditis
  • Type I diabetes

Additionally, a person can develop more than one autoimmune disorder at a time. For example, if you have celiac disease (gluten intolerance), you might establish pernicious anemia also.


Uterus or cervix infections can be harmful to an establishing baby and result in miscarriage. Other infections that may pass to the baby or placenta can also affect an establishing pregnancy and might lead to loss. A few of these infections include: listeria, parvovirus B19, toxoplasma gondii, rubella, herpes simplex, and cytomegalovirus.

Risk of Miscarriage According to Period of Pregnancy

The first trimester of pregnancy is thought about weeks 0 to 13. About 80 percent of miscarriages happen in the first trimester. Losses after this time take place less frequently. March of Dimes reports a miscarriage rate of just 1 to 5 percent in the 2nd trimester.

Weeks 0 to 6

These early weeks mark the greatest risk of miscarriage. A woman can have a miscarriage in the first week or 2 without understanding she’s pregnant. It may even seem like a late period.

Age contributes in a woman’s risk factor. One study showed that compared to women younger than 35:

  • Women ages 35 to 39 have a 75 percent increase in risk
  • Women ages 40 and older are at 5 times the risk

Weeks 6 to 12

As soon as a pregnancy makes it to 6 weeks and has actually verified practicality with a heart beat, the risk of having a miscarriage drops to 10 percent. According to a 2008 study, the risk for miscarriage falls rapidly with further gestational age. However, this was not specifically studied in patients with other risk factors for miscarriage.

Weeks 13 to 20

By week 12, the risk may fall to 5 percent. However bear in mind that it doesn’t actually fall below that due to the fact that issues can occur during pregnancy.


Be mindful that you can do whatever “right” and still have a miscarriage. Try not to add guilt or self-blame to your emotional problem. In between working with your doctor and making healthy lifestyle changes, you can rest easy knowing you’ve done whatever you can to have a healthy pregnancy.

References / About Reyus Mammadli (article's author)

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