• When there is a history of three miscarriages, it is referred to as recurrent pregnancy loss.
• The tests look for genetic, anatomical, immunological, and hormonal causes.
• The prognosis for achieving a successful pregnancy is generally good.

The most commonly studied causes are:

1. Genetic: there may be alterations in the genetic information that the parents pass on to their children, even if the parents appear to be normal.

2. Uterine: a woman may have abnormalities in her uterus that hinder the normal development of the placenta and pregnancy. A common abnormality is the presence of septa, which are walls of fibrous tissue inside the uterus that divide the uterine cavity into two smaller cavities. Septa are congenital in origin. Another frequent abnormality, this time acquired, is the presence of adhesions in the uterine cavity, which occur following infectious or inflammatory processes.

3. Immunological: the immune system is responsible for defending our body against invasions or infections by bacteria, fungi, or other cells, such as cancer. To do this, the system must recognize which cells are normal and belong to the body, and which are foreign, in order to attack and destroy them. Pregnancy is a very special situation in which the immune system must tolerate the presence of a foreign organism and not attack it. In some circumstances, this tolerance mechanism does not work, and the embryo is rejected. This can be the reason why pregnancies are repeatedly lost in the early weeks. People with autoimmune diseases (lupus, rheumatoid arthritis, etc.) are more prone to this problem.

4. Endocrine: for a pregnancy to develop normally, certain hormone levels need to be within an adequate range. The main necessary hormone is progesterone, initially produced by the ovary. When levels are low, pregnancy loss can occur.

5. Infectious: infection as a cause of recurrent miscarriages is a widely held popular belief. Although some infections can cause pregnancy loss, there does not appear to be any type of infection that causes pregnancies to be lost repeatedly.

1. Karyotype of the couple: examines the chromosomes, which are the part of the cell where genetic information is packaged, and is the simplest initial genetic study. There are other, more complex studies that analyze specific genetic information. However, it should be noted that currently there is no efficient way to analyze all 30,000 human genes with their multiple normal and abnormal variations.

2. 3D Ultrasound: this is the initial study of the uterus. Sometimes hysteroscopy is used, which involves inserting a thin telescope with a video camera through the vagina into the uterus. During the same procedure, some of the abnormalities can be corrected.

3. Autoimmunity study: a blood test for antibodies, including IgG and IgM anticardiolipin, Beta-2 glycoprotein, and lupus anticoagulant.

4. Blood hormone measurements: progesterone, thyroid hormone, and prolactin levels are measured.