Causes of Recurrent miscarriage: What do you need to know?

Causes of Recurrent miscarriage

Recurrent miscarriages refer to the loss of two or more clinically proven pregnancies. Pregnancies that have evidence like laboratory indications of the placenta or an early ultrasound that can prove the pregnancy are known as clinically proven pregnancies. Recurrent miscarriages generally occur involuntarily within the first 20 weeks of pregnancy. There are about 15% cases of miscarriage in clinically proven pregnancies. The rate of occurrence of recurrent miscarriages is very low, ranging from about 1-5%. The cases of two recurrent losses in pregnancy are approximately 2% and the cases of three recurrent miscarriages are about 1%. The causes of recurrent miscarriages are usually different in different cases.

Recurrent miscarriages do not mean that the woman cannot have a healthy pregnancy in the future. To ensure a healthy pregnancy in the future, it is very important to know the cause of recurrent miscarriages so that proper treatment can be provided. In most cases of recurrent miscarriage, it is observed that after regular monitoring by their doctors and support from loved ones, women are able to give birth to a healthy baby, and that too without any treatment. Therefore, it is very important for women to remember that the chances for a future healthy pregnancy are very high in almost all women with recurrent miscarriages

There can be various causes of recurrent miscarriages ranging from genetic issues to environmental issues and it is very important to know the main cause of recurrent miscarriage so that future mishaps can be prevented.

Several causes of recurrent miscarriages are:

Table of Contents

Feel free to skip ahead if one topic catches your eye:

  1. Genetic or Chromosomal Problems of The Embryo
  2. Endocrine Issues like Thyroid & Diabetes
  3. Uterine Structural Problem
  4. APS that causes Blood clotting Disorders
  5. Environmental Factors


1. Genetic or Chromosomal Problems of the Embryo

Chromosomal abnormalities are one of the main reasons for recurrent miscarriages. Approximately 50-70% of the miscarriages are due to chromosomal issues. Chromosomal abnormalities refer to missing chromosomes, duplicated chromosomes, or any mutations or changes in the chromosome of the growing fetus that does not allow the fetus to grow properly, ultimately leading to miscarriage. The mutations occurring in the chromosome are random, but in the case of recurrent miscarriages, these mutations can be associated with a single mutation commonly known as a balanced translocation.

These genetic abnormalities can be caused due to the following reasons

  • Either of the parents having a similar genetic issue
  • Women becoming pregnant at an age of 35 years or above
  • It might also be because of exposure to toxic chemicals

Sometimes, the immune system of the mother detects these genetic problems in the growing baby and thus, ends the pregnancy, or sometimes these mutations lead to certain missing genes that are required for cell division and development of the fetus, ultimately leading to a miscarriage.
The treatment of recurring miscarriages due to genetic defects and chromosomal abnormalities is possible if they are diagnosed at the right time.

2. Endocrine issues like Thyroid & Diabetes

Hormones secreted by the endocrine gland play a vital role in maintaining the pregnancy. Any abnormalities related to the endocrine gland, like uncontrolled diabetes or thyroid can cause an adverse effect on the growth of the developing fetus. About 8-12% of the cases of recurrent miscarriage are due to endocrine issues. Hormones are majorly responsible for the proper implantation and development of the fetus. During pregnancy, it is natural for the hormonal levels to rise. Thus, it is very essential to regularly monitor the level of hormones in females especially if they have endocrine dysfunction-related issues like uncontrolled diabetes and thyroid. Endocrine issues or hormone-related problems are diagnosed through tests like glucose screening (to diagnose diabetes) or blood tests (to monitor levels of hormones like thyroid, progesterone, and prolactin).
The treatment of recurrent miscarriages due to endocrine issues is possible through regular monitoring of the hormone levels and undergoing certain lifestyle changes that will help control conditions like diabetes and thyroid.

3. Uterine structural problems

The uterus is the main body organ where the fetus actually grows and develops. Any abnormality in the structure of the uterus can affect the growth of the fetus. About 18% of the cases of recurrent miscarriage are due to problems in the uterine structure. Though there can be many problems in the uterine structure of a female, they generally don't show any symptoms, and therefore, one doesn't even know about these problems before they become pregnant. Not all uterine problems affect the growth of the fetus. Only those uterine problems which are related to the shape and size of the uterus, actually affect the development of the fetus. Uterine issues include problems like the uterine septum and the deformed shape of the uterus. The uterine septum is a thin lining that partially or completely divides the uterus into two halves because of which the placenta does not get enough space to grow and leads to a miscarriage. Deformities in the shape of the uterus include a heart-shaped nucleus (bicornuate uterus), horn-shaped uterus which is smaller than the normal uterus (unicornuate uterus), and a T-shaped uterus. Other causes that can be responsible for recurrent miscarriages are the presence of two uteri in a female or cervical insufficiency, that is, the cervix starts dilating very early in pregnancy. This may lead to preterm delivery or second-trimester miscarriage. Fibroids, that is, the non-cancerous growth of connective tissue and muscle from the wall of the uterine can also lead to miscarriage depending upon the position of the fibroids in the uterus.
The treatment of recurrent miscarriages due to uterine structural problems is possible if they are diagnosed in time.

4. Autoimmune diseases: Antiphospholipid antibody syndrome (APS)

APS, that is, the antiphospholipid syndrome is a rare autoimmune disorder that affects the normal cycle of bleeding and blood clotting. APS in women results in blockage of blood flow and formation of clots leading to stroke or heart attack if not treated. Approximately 15% of the cases of recurrent miscarriage are due to APS. In pregnant women, due to clotting of blood, the blood flow to the placenta is disrupted due to which blood cannot reach the growing fetus causing miscarriage. APS is generally diagnosed through blood clotting tests or antiphospholipid antibody tests (aPL tests). There are 70% chances for a woman with APS to have a normal pregnancy.
The treatment of recurrent miscarriages occurring because of APS is possible by prescribing a low dose of aspirin or heparin injections. In case of high severity, both aspirin and heparin are prescribed.

What are the factors that increase the risk of miscarriage?

5. Lifestyle and Environmental Factors

Lifestyle is directly linked to the health of an individual. A healthy and balanced lifestyle will ensure that the individual is free from any health issues. Lifestyle factors include the factors which we are exposed to due to our pattern of living. Environmental factors refer to those causes of recurrent miscarriage that are due to exposure to certain toxic chemicals present in the surrounding of a pregnant woman. Pregnant women might get exposure to heavy metals like Mercury, Ionizing Radiation (like X-rays), Anesthetic Gases, Organic Solvents and Lead due to the occupation they are associated with. Due to the adverse effect of ionizing radiation on the health of the growing fetus, flight attendants and pilots have a higher risk of such losses. Alcohol consumption even in small amounts can lead to miscarriage. Similarly, smoking cigarette is very injurious for a pregnant lady and the unborn child because of the presence of nicotine in cigarettes and its byproducts accumulate in the blood vessels of the uterus causing recurrent miscarriages in such women. Consuming coffee or caffeinated beverages by an expecting mother has also been shown to cause miscarriages in the first trimester itself. Obesity is also associated with an increased risk of miscarriage
The treatment of recurrent miscarriages caused due to exposure to lifestyle compounds is only possible if the pregnant woman stops herself from getting exposed to such compounds. For best treatment consult the best gynaecologist and obstetrician Dr Preeti Singh in Nodia at Sparsh center for women care in sector 93.


It is very important for a couple to remember that in most cases of recurrent miscarriage, women do have a full-time healthy pregnancy in the future. A little care, positive attitude, constant support, and proper consultation of the doctor can help a woman conceive naturally without any treatment.