5 Common Causes of Miscarriages

Miscarriages happen in around 10 to 20 percent of pregnancies. Read on to find out what are the most common causes of miscarriages.
5 Common Causes of Miscarriages
María Belén Del Río

Reviewed and approved by the doctor María Belén Del Río.

Written by Naí Botello

Last update: 27 December, 2022

A miscarriage is the loss of the fetus during the first 20 weeks of pregnancy. Miscarriages are a common occurrence because a high percentage of pregnancies can be at risk. Causes of miscarriages can differ from one another, but the very presence of one or several of these causes can spontaneously terminate a pregnancy.

If you’d like to fully understand this, don’t miss out on the information in this article.

Understanding miscarriages

A miscarriage, or spontaneous abortion, is the early termination of a pregnancy. This happens when the fetus dies and is expelled from the mother’s body.

A spontaneous abortion happens before 20 weeks of pregnancy, or 24 weeks at a maximum. After this, it’s classified as stillbirth.

Miscarriages can come in many forms. Sometimes, the mother only shows a few symptoms, but her cervix remains closed. In these cases, bed rest and medical checkups can help avoid the expulsion. This is known as a threatened abortion.

Other times, it might be an inevitable miscarriage, where the cervix opens up and the expulsion happens. Lastly, an incomplete miscarriage might occur when the fetus has died but it doesn’t get expelled from the mother’s body.

In this case, through medical treatment or a minor surgical procedure, the residues can be extracted and this ends the pregnancy.

Infections can be a cause of miscarriages.

Symptoms of a miscarriage

Every pregnant woman needs to know and pay attention if she notices any of these symptoms, as it will help her detect any signs of spontaneous abortion:

  • Vaginal bleeding and blood clots
  • Abdominal pain and cramping
  • Low back pain
  • Fever or chills
  • Headache
  • Abnormal vaginal secretions or with a foul odor

5 causes of miscarriages

Miscarriages can have many causes. These can be traumas, diseases or infections, genetic disorders, malnutrition, or substance abuse. However, the most common causes that can terminate a pregnancy are:

Issues in the cervix or uterus

Common medical causes for miscarriages are congenital abnormalities of the uterus, poor wound healing after surgery, or cervical insufficiency, meaning a very weak cervix, and the presence of uterine fibroids. However, this last condition hasn’t been entirely proven to affect pregnancies.

Abdominal pain can be a cause of miscarriages.

Chronic illnesses

A chronic illness can definitely affect a pregnancy. Among the most harmful diseases for pregnancy, there’s diabetes, immunological diseases like lupus, HIV, blood clotting problems, and polycystic ovary syndrome.

Infectious diseases like mumps, rubella, measles, gonorrhea, and listeria can affect pregnancies as well.

Drug use, alcohol or tobacco

The use of these highly addictive and detrimental substances can pose a huge risk of spontaneous abortion. Besides, pregnant women need to be careful about medicines, infusions, or excess coffee they consume because some studies suggest these might have negative effects on pregnancies.


Age can contribute to developing a miscarriage, both for women over 35 years old, as for teenage mothers. In fact, women over 35 have twice the risk of suffering a miscarriage than that of women of other age groups.

High chromosome count

When the fertilized egg has an abnormally high chromosome count, usually, the mother’s body will reject the embryo and a miscarriage will occur.

Pregnant women need lots of sleep.

In addition to the most common causes of miscarriage mentioned above, there are other causes you should be aware of, such as being obese, having had miscarriages before, having suffered injuries and traumas, malnutrition, and having consumed some anti-inflammatory medicines.

Now that you have all this information, pay attention to your body and see your doctor whenever you see fit.


All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Castillo, S., Fuentes, A., Paulos, A., & De la Rosa, E. (2014). Estudio cromosómico en abortos espontáneos. Revista Chilena de Obstetricia y Ginecología. https://doi.org/10.4067/S0717-75262014000100007
  • Martinez-Garcia, M., Gavin, E., Plaza, J., Perez-Aytes, A., Marin-Reina, P., Lorda-Sanchez, I., … Trujillo-Tiebas, M. J. (2016). Recomendaciones de buenas prácticas para el diagnóstico genético de abortos espontáneos e interrupciones voluntarias del embarazo por presentar defectos congénitos. Clinica e Investigacion En Ginecologia y Obstetricia. https://doi.org/10.1016/j.gine.2015.03.004
  • Garrido Calderón, J. E. (1995). El Aborto En La Historia. Acta Medica Dominicana.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.