What other causes might be behind recurrent miscarriages?
Although genetic abnormalities are the most frequent cause of early miscarriages, they are not the only contributing factor. Dr. Vega Cabezuelo explains that the investigation of recurrent miscarriages must be comprehensive, as there are various causes that can affect the normal development of a pregnancy.
Uterine abnormalities: the place where the embryo should implant
"The uterus is the place where the embryo has to implant, so it is essential to check that it has adequate conditions," explains Dr. Vega Cabezuelo.
For this purpose, the study usually includes a gynecological ultrasound , preferably a three-dimensional one, which allows for a more precise assessment of the uterine anatomy. In some cases, a diagnostic hysteroscopy is also performed , a technique that involves inserting a small camera into the uterus to directly visualize the endometrial cavity.
In addition, when indicated, the study can be completed by means of an endometrial biopsy.
The purpose of these tests is to detect possible abnormalities, such as congenital uterine malformations , polyps, fibroids, or uterine septa. Some of these abnormalities can be corrected surgically, thus improving the chances of a successful pregnancy.
Immunological factors: the importance of tolerance to the embryo
During pregnancy, the maternal immune system must develop a delicate balance that allows it to accept the embryo, whose cells also contain paternal genetic material.
"Immunological tolerance is necessary for the pregnancy to develop normally," the specialist points out.
Within this category, one of the best-known diseases is antiphospholipid syndrome , an autoimmune disorder in which certain antibodies promote the formation of small blood clots in the blood vessels of the developing placenta. These microthrombi can hinder the proper development of the pregnancy and increase the risk of miscarriage.
Dr. Vega Cabezuelo adds that there are also increasingly promising lines of research related to the study of histocompatibility , that is, the interaction between certain proteins of the maternal endometrium and the embryo, a field that continues to advance thanks to new research.
Thrombophilias: when the blood clots more than normal
Another possible cause being studied is thrombophilia , hematological diseases that promote a greater tendency to coagulate.
In these patients, small thrombi may form in the placental circulation, hindering the adequate supply of oxygen and nutrients to the embryo during the early stages of pregnancy.
Identifying these disorders is crucial, as some have treatments that can reduce the risk of further pregnancy losses.
Endocrine and metabolic diseases
Hormonal balance also plays an important role in the success of pregnancy.
Among the endocrine disorders that may be associated with recurrent miscarriages are:
- poorly controlled diabetes mellitus.
- Obesity.
- Hyperprolactinemia.
- Vitamin D deficiency, whose relationship with recurrent miscarriages continues to be studied.
"Many of these disorders can be diagnosed and treated before trying for a new pregnancy," explains Dr. Vega Cabezuelo.
Lifestyle habits that can also influence
In addition to medical causes, there are certain lifestyle-related factors that can increase the risk of pregnancy loss.
Tobacco use , alcohol consumption, or high caffeine intake , as well as continued exposure to certain toxic substances, have been associated with a higher risk of miscarriage.
Therefore, adopting healthy lifestyle habits before conception is one of the most important preventive measures to promote a healthy pregnancy.
A personalized study for each couple
Not all couples need the same tests or have the same underlying causes. Therefore, Dr. Vega Cabezuelo emphasizes that the evaluation of recurrent miscarriages should be individualized, selecting the most appropriate tests based on each patient's medical history.
The goal is to identify factors that can be acted upon, offer the most appropriate treatment when there is a correctable cause, and support the couple throughout the reproductive process.
Although in some cases a specific cause cannot be identified, the prognosis remains favorable: most couples with recurrent miscarriages will eventually achieve a successful pregnancy and the birth of a healthy child, especially when they have specialized follow-up.