Recurrent Miscarriages
Are recurrent miscarriages a symptom of infertility? All the information about recurrent miscarriages: causes, tests, and treatments.
Symptoms and Causes
A recurrent miscarriage, or recurrent pregnancy loss, refers to when a woman has experienced at least three consecutive spontaneous miscarriages before the 20th week of pregnancy. There is no issue with sterility, as conception is possible, but infertility is the problem, as the pregnancy does not reach full term.
There are two types of recurrent miscarriages:
- Primary recurrent miscarriage: no pregnancy has been carried to term.
- Secondary recurrent miscarriage: a child has been previously conceived and born alive.
Although spontaneous miscarriage during the first trimester is a common complication that does not necessarily prevent a subsequent pregnancy, when consecutive recurrent miscarriages occur, it signals an underlying problem or pathology that prevents the pregnancy from reaching full term.
Symptoms
Recurrent miscarriage presents the same symptoms as any spontaneous miscarriage. Occasionally, this happens without symptoms, but it is usually characterized by:
- Vaginal bleeding or spotting.
- Intense pain or cramping in the pelvic area, abdomen, or lower back.
- Rapid heartbeat.
- Expulsion of liquid or tissue from the vagina.
Causes
Although the cause of recurrent miscarriages is not determined in a high percentage of cases, possible causes include:
- Genetic abnormalities in the embryo: Chromosomal abnormalities, present in the genes or that occur during fetal development, can lead to a non-viable embryo.
- Uterine abnormalities: The presence of congenital malformations, fibroids, polyps, or lesions can hinder fetal development. Endometrial disorders can also cause a miscarriage.
- Immunological problems: Antiphospholipid syndrome is an autoimmune disorder that causes blood clots, which can reach the placenta and interrupt blood flow to the fetus, causing pregnancy loss. Thrombophilic conditions can produce the same effect. In some cases, the mother’s immune system fails to recognize the fetus as her own, releasing antibodies to reject it (known as Natural Killer cells, NK).
- Hormonal imbalances: Thyroid disorders, progesterone deficiency, polycystic ovary syndrome, diabetes, or excess prolactin can cause pregnancy loss, although they are not frequent causes.
Risk Factors
Several factors increase a woman's likelihood of experiencing recurrent miscarriages:
- Age: After 40 years, the risk of a miscarriage increases up to 50%.
- Previous history of miscarriage.
- Consumption of harmful substances such as alcohol, tobacco, caffeine, or drugs.
- Exposure to environmental toxins like radiation or heavy metals.
- Obesity or being underweight.
Complications
In addition to the profound emotional impact on both parents, which may cause anxiety and depression, a miscarriage can lead to serious medical consequences for the mother, such as infections or hemorrhages. Moreover, recurrent miscarriages can lead to long-term fertility issues.
Prevention
Several measures can be taken to reduce the risk of recurrent miscarriage:
- Taking folic acid and other pregnancy-related supplements.
- Maintaining strict medical supervision of the next pregnancy after an initial miscarriage.
- Following a healthy diet.
- Maintaining a healthy weight.
Which doctor treats recurrent miscarriages?
Recurrent miscarriages are evaluated and treated by specialists in gynecology and obstetrics and in assisted reproduction units.
Diagnosis
As soon as three consecutive spontaneous miscarriages occur, or even two, certain tests should be performed on both parents to determine the underlying cause:
- Hormonal analysis of the woman to check levels of prolactin and progesterone, as well as thyroid function.
- Thrombophilia screening to assess altered coagulation factors.
- Immunological tests to detect the presence of antiphospholipid antibodies and NK cells.
- Imaging tests, such as ultrasound, hysterosalpingography, or hysteroscopy, to examine the uterine cavity and identify malformations or lesions.
- Endometrial biopsy to examine the structure of endometrial cells.
- DNA fragmentation study of sperm: DNA structure in sperm is analyzed from a semen sample to check for lesions or breaks.
- Sperm FISH (fluorescence in situ hybridization): fluorescent probes are used to identify chromosomal abnormalities in sperm.
- Karyotype studies for both the woman and the man to identify abnormalities in chromosome number or structure.
Treatment
The treatment selected depends on the results of the diagnostic tests:
- Surgery to correct uterine malformations.
- Medication to regulate hormonal imbalances.
- Anticoagulants in cases of antiphospholipid syndrome or thrombophilias.
- Progesterone in cases of recurrent miscarriage with no apparent cause.
- Assisted reproductive techniques when recurrent miscarriages are caused by genetic abnormalities:
- In vitro fertilization (IVF): Eggs and sperm are retrieved, fertilized, and incubated in the lab, and the resulting embryo is then implanted into the woman’s uterus. Intracytoplasmic sperm injection (ICSI) is a variant of IVF where a single sperm is directly injected into the egg.
- Preimplantation genetic diagnosis (PGD): A biopsy is performed on embryos in incubation to extract several cells and study their DNA. This allows for the exclusion of embryos with genetic alterations and the selection of genetically healthy embryos for implantation.
- Gametocyte donation: If the genetic cause cannot be identified or if viable embryos are not obtained after PGD, egg or sperm donation may be used.
