Recurrent Miscarriage

Recurrent miscarriage, is defined as two or more pregnancy losses. This includes pregnancies after spontaneous conception and after fertility treatments. Recurrent miscarriage affects 2-5% of couples trying to conceive.

A pregnancy loss can have a significant emotional impact on women and their partners, and this impact may increase with each additional loss. You may experience feelings of loss, grief, or a sense of failure, which is normal and understandable.

It is important to see a fertility specialist to identify the likely cause of your previous pregnancy losses, to discuss appropriate treatment, to estimate your prognosis and explore options for emotional support.

There are many proposed causes of recurrent miscarriage, but for majority of patients no cause is found.

The known causes of recurrent miscarriage include:

Genetic causes: The majority of miscarriages occur as a result of genetic abnormalities in the embryo, such as an extra chromosome or missing chromosomes. Genetically abnormal embryos are often the result of poor oocyte or sperm quality, which deteriorate with age. Less commonly, chromosomal rearrangement (translocation) in one of the parents can cause genetic abnormality in an embryo.
Müllerian duct anomalies: Müllerian anomalies are rare developmental anomalies of female reproductive tract, which can disrupt the development of the fallopian tubes, uterus, cervix, or upper two-thirds of the vagina. The most commonly reported anomalies associated with miscarriage are uterine septum, uterus didelphys, bicornuate, unicornuate or hypoplastic uteri.
Fibroids: Fibroids are common and can be categorised as subserosal (project to the outside of the uterus), intramural (located within uterine wall) and submucosal (project into the uterine cavity). Submucous and some intramural fibroids may decrease live birth and increase miscarriage rates.
Thrombophilia: Thrombophilia is a group of conditions in which there’s an imbalance in naturally occurring blood-clotting factors. Some people are born with thrombophilia (inherited thrombophilia), while other people develop thrombophilia later in life (acquired thrombophilia). In either case, the condition has many forms and may increase the risk of miscarriage, pregnancy complications or blood clots.

Hormonal disorders: Poorly controlled diabetes, thyroid disorders, high prolactin levels, abnormal progesterone production or polycystic ovary syndrome (PCOS) are associated with increased risk of miscarriage.
Immune system derangements: There has been increasing interest in the role of abnormal immune responses in recurrent pregnancy losses. The examples include natural killer cells and various auto-antibodies (an antibody made against substances formed by a person’s own body).
Endometriosis: Growing evidence links endometriosis to recurrent miscarriages. The proposed explanations include reduced egg quality, inflammation and problems with uterine receptivity although an exact cause remains unclear.
Environment and lifestyle: Cigarette smoking, alcohol, and caffeine intake are linked to increased rates of miscarriage in dose-dependent manner. Illicit drug use, especially cocaine use, leads to an increased risk of miscarriage. Female obesity is linked to increased miscarriage rates and can cause other pregnancy-related complications.
Male factors: Growing evidence links high sperm DNA fragmentation (the amount of damage seen in sperm DNA) with recurrent miscarriage. Sperm DNA damage does not always correlate with semen parameters and can be noted in men who have a normal sperm count, motility, and morphology.

Treatments for recurrent miscarriage depend on the underlying cause and may include:

Lifestyle changes: Maintaining a healthy weight, quitting smoking, and reducing alcohol and drug use can all reduce the risk of recurrent miscarriage.
Medications: Medications that may help to reduce the risk of miscarriage include treatments for the underlying hormone condition (thyroid or diabetes). Blood thinners in women with thrombophilia or auto-immune disbalances improve chances for healthy pregnancy. Anti-oxidant supplements may reduce sperm DNA fragmentation and improve sperm health.

Surgery: Surgery can be used to remove uterine septum or fibroids, divide uterine adhesions or resect endometriosis, which may improve chances for healthy pregnancy.
Assisted reproductive technologies (ART): In vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) with preimplantation genetic testing of embryos (PGT-A) improves selection of genetically normal embryo and decreases the risks of miscarriage.

Dr Victoria Nisenblat

MD, PhD, FRANZCOG, CREI

Fertility Specialist, Obstetrician, Gynaecologist and Reproductive Surgeon

Dr Victoria Nisenblat is an experienced Gynaecologist with 20+ years of experience managing gynaecological conditions medically and surgically where indicated. She is also a certified Fertility Sub-Specialist, having completed the Certificate of Reproductive Endocrinology and Infertility (CREI).

Recurrent Miscarriage