Your diagnosis
Miscarriage is a very sad experience and if it recurs it can become traumatic. Approximately 15 % of pregnancies end in miscarriage before the ninth week of pregnancy.
Recurrent miscarriages are when two or more non-evolving pregnancies occur consecutively. In these cases, each miscarriage increases the likelihood of recurrence in subsequent pregnancies, as it indicates that there is a common cause.
Diagnosis Treatment Pregnancy Loss Chromosomal abnormalities in the embryo are the most common cause of recurrent miscarriages, accounting for 50-60 % of cases. This percentage increases with the woman’s age. These abnormalities can occur during embryo formation and be inherited from either parent.
Approximately 4% of couples with recurrent miscarriages have a chromosomal abnormality in the karyotype of one of the parents. The karyotype is analysed by a blood test. It is the representation of a person’s chromosomes arranged according to their morphology and size. Each cell has 46 chromosomes, 23 pairs inherited from the mother and 23 from the father.
Chromosomal abnormalities often affect the karyotype structure: missing a piece or having an extra piece. In the carrier parent the alteration is in balance, but it can be transmitted in an unbalanced way.
The vast majority of miscarriages are due to alterations in the number of chromosomes in the embryo because the sperm and/or the egg do not have the appropriate chromosomal endowment. According to studies carried out at Institut Marquès, in the best of situations, i.e. embryos from donor sperm and eggs, almost half of them have chromosomal abnormalities. It seems a lot, but human reproduction is not very efficient.
The percentage of abnormal embryos increases with the age of the woman, with 78% of the embryos of patients in their 40s being altered.
In the egg cell nucleus, after ovulation, the 46 chromosomes are placed face to face to separate. The filaments that bind them together are released, leaving 23 chromosomes. As a woman gets older, the passage of time causes alterations in this process (in young women the rods that separate them effectively are resistant. With age they become weaker and can break like the filaments of a light bulb). Therefore, there may be extra chromosomes left over (if it is 21 it will give rise to Down’s Syndrome) or less, causing fertilisation failures or embryos with genetic alterations which will mostly be early miscarriages
The risk of miscarriage for a 35-year-old woman is 20%, at 40 years of age 40%, and at 45 years of age 80%. However, ovarian age is not always the same as chronological age.
In order to know the risk of another miscarriage, we must study the patient’s ovarian reserve by analysing the anti-mullerian hormone (calculate your ovarian age by clicking on this link). To rule out that it is due to abnormalities in the chromosomal endowment of the sperm, a study in semen called FISH is recommended. Meiosis and double-stranded DNA fragmentation studies may also be adviced.
The indicated treatment for recurrent miscarriages caused by genetic alterations is In Vitro Fertilisation with Genetic Analysis of the Embryos (PGT). In this way, only chromosomally healthy embryos are transferred into the mother’s uterus.
In the case of a miscarriage, we can already determine a possible genetic cause with just a blood test.
The most common cause of miscarriage is chromosomal abnormalities in the embryo. A blood test of the patient now allows us to determine the karyotype of the non-evolving embryo within 4 days.
As soon as the embryo is implanted, embryonic DNA is found in the mother, so the analysis can be carried out following any miscarriage, even with only a week’s delay.
This is a great advance because when this study is carried out on the abortion remains, by means of curettage or chorion biopsy, there are many failures when it comes to obtaining the result and, in addition, the sample may have been contaminated with DNA from the mother.
At Institut Marquès we obtain the blood sample in our own clinic to carry out the “PregnancyLoss” analysis. The total cost is 480 euros.
Antiphospholipid Syndrome or Acquired Thrombophilia. This occurs when the immune system mistakenly produces antibodies that increase the likelihood of blood clots forming. It is considered responsible for 10-15 % of miscarriages. It is also called Acquired Thrombophilia.
Autoimmune Hypothyroidism, Hashimoto’s Thyroiditis: in this disease the immune system attacks the thyroid and often prevents it from producing sufficient amounts of thyroid hormones. These hormones are related to the ovarian cycle and embryo implantation.
Celiac Disease. This is an autoimmune disease whose most common symptoms are chronic musculoskeletal pain, headaches and physical and mental fatigue.
Other immunological factors, such as KIR genotype, HLA-C typing, NK (natural killer) cells and anti-parental antibodies have been linked to miscarriages and implantation failures but there is NO scientific evidence. Although experimental studies have been done, it is currently believed that they should not be analysed, much less treated.
Hereditary thrombophilia is a genetic predisposition to increased blood clotting. It is due to genetic variants of proteins involved in coagulation. As a result, thrombi can form, particularly in the legs, which can break off and cause pulmonary thromboembolism.
Pregnancy induces a state of hypercoagulability in all women, a physiological change to prevent haemorrhage during childbirth. In patients with Thrombophilia, thrombosis can occur in the placenta, reducing the vascularisation of the foetus and causing miscarriages. There is also a higher risk of postpartum thromboembolism.
The standard test for diagnosing genetic thrombophilia is a blood test for Protein C, Protein S, Antithrombin III and Leyden’s Factor V. But this test can only identify 20% of cases. The study of the genetic profile of thrombophilias allows 85% of patients with this disease to be detected.
Treatment for patients with genetic Thrombophilia is carried out on an individualized basis with Low Molecular Weight Heparin.
Congenital uterine malformations are those in which the uterus is very small or deformed, or there is a fibrous septum dividing the uterine cavity into two (septate uterus). The incidence of these malformations is 0.3 % in the general population and approximately 4 % in patients with miscarriages.
Alterations of the uterus are diagnosed by means of:
No. If thyroid disorders or diabetes are medically controlled, they are NOT a cause of miscarriage. There is also no scientific evidence that hyperprolactinemia or luteal insufficiency cause recurrent miscarriages.
No. Some infections like listeriosis can cause pregnancy loss in the first trimester, but they are NOT a cause of recurrent miscarriages.
Intense stress can affect the regulation of cortisol and catecholamines, and could decrease the oxygen supply to the fetus, causing growth retardation. But it is NOT a cause of miscarriage.
In many patients who have experienced miscarriages, even with diagnostic tests, the cause is not always identified. The important thing is to know the risk of recurrence:
These percentages are general and may vary if there are factors that increase or decrease the risk (for example, antiphospholipid syndrome, advanced maternal age, or chromosomal analysis of embryos).
Yes. In the last decade, there have been significant advances in the diagnosis of recurrent miscarriages, especially those of embryonic origin. Even so, identifying the cause in every case remains a challenge. Thanks to research, there are now more tests and treatments available to address these situations.
More information about
At Institut Marquès we have all Assisted Reproduction treatments in which we use the most advanced technology.
More information about
We finance all your Assisted Reproduction treatments. Calculate it yourself with our new financing calculator.
More information about
We are different from other centers: restless professionals who constantly seek improvement and excellence.
One of our team members will be in touch shortly through your preferred method of communication.
Fill out the form and we will contact you to arrange a visit with a specialist in Assisted Reproduction.
