Recurrent miscarriages can result from genetic, hormonal, anatomical, environmental, or immunological factors. In some cases, despite thorough medical evaluations, no clear cause is identified—this is referred to as idiopathic recurrent miscarriage.
Genetic Causes
Certain chromosomal abnormalities in either parent can lead to repeated pregnancy loss. One such example is chromosomal translocation, where pieces of genetic material are rearranged, potentially leading to non-viable embryos. Additionally, trisomies (16, 22, 21, 15, 14, 18) and Turner syndrome (45,X0) are among the most common chromosomal issues found in miscarried embryos, accounting for around 50% of first-trimester losses.
Hormonal & Endocrine Factors
Unbalanced thyroid function or poorly controlled diabetes can impair the body’s ability to support a pregnancy. Additionally, polycystic ovary syndrome (PCOS), especially when associated with excess weight, has been linked to a higher risk of miscarriage due to hormonal imbalances and insulin resistance.
Anatomical Factors
Structural abnormalities of the uterus can interfere with embryo implantation and pregnancy progression. Congenital malformations, such as a septate uterus, and acquired conditions, like severe intrauterine adhesions (Asherman’s syndrome) or exposure to DES (diethylstilbestrol), have been associated with recurrent miscarriage. While fibroids that distort the uterine cavity can increase the risk of pregnancy loss, a bicornuate uterus (a congenital malformation with two cavities) is generally not considered a direct cause.
Environmental & Lifestyle Factors
Smoking, exposure to tetrachloroethylene (a chemical used in dry cleaning), and other environmental toxins may increase the risk of pregnancy loss. Maternal lifestyle habits and chronic stress can also play a role, although the direct mechanisms are still under investigation.
Infectious Factors
No conclusive evidence links bacterial or viral infections to recurrent miscarriage, meaning routine antibiotic treatment is not recommended. However, if infections like Ureaplasma urealyticum or Listeria monocytogenes are detected, they should be treated appropriately.
Immunological Factors
An overactive immune system may also contribute to recurrent pregnancy loss. One well-established condition is antiphospholipid syndrome (APS), an autoimmune disorder that leads to the formation of micro-blood clots, affecting placental development. While early research suggested that intravenous immunoglobulin (IVIG) therapy might help in cases of immune system overactivation, studies have not demonstrated a clear benefit.
Learn. Improve. Maintain.
Recurrent miscarriage is a complex condition with multiple potential causes. Learning about contributing factors, improving health through medical evaluations and personalized care, and maintaining a proactive approach with fertility specialists can help optimize future pregnancy outcomes.
