The reasons for recurrent miscarriage can be complex and multifaceted. Understanding these causes can help couples seek appropriate medical assistance and potentially prevent future losses.
Recurrent miscarriage, also known as recurrent pregnancy loss (RPL), is defined as the loss of three or more pregnancies before 20 weeks of gestation. It affects approximately 1-2% of couples trying to conceive. While a single miscarriage is relatively common, recurrent miscarriages can signal underlying health issues that need to be addressed.
One of the most common reasons for miscarriage is genetic abnormalities in the embryo. Approximately 50-60% of all first trimester miscarriages are due to chromosomal abnormalities in the fetus. These abnormalities can occur randomly during the formation of the egg or sperm or may be inherited from one or both parents. However, this is a less common cause when the miscarriages become recurrent.
While most chromosomal abnormalities result in a single miscarriage, certain genetic conditions like balanced translocation (where parts of chromosomes have switched places) can increase the risk of recurrent losses. Genetic testing on both partners and possibly on fetal tissue after a miscarriage can help identify if this is the cause.
Structural problems with a woman’s uterus or cervix can also lead to recurrent pregnancy loss. Conditions such as uterine fibroids, congenital uterine anomalies (like a septate uterus), or an incompetent cervix that cannot stay closed as the fetus grows may contribute to repeated losses.
These conditions often require surgical intervention or other treatments to correct them before a successful pregnancy can occur. A thorough evaluation by an gynecologist may be necessary to identify these issues.
Hormones play a crucial role in maintaining a healthy pregnancy. Imbalances or deficiencies in certain hormones, particularly progesterone and thyroid hormones, can lead to miscarriage. Progesterone is essential for preparing the uterus for pregnancy and supporting the early embryo.
Thyroid disorders, both hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid), have been linked to increased risk of miscarriage. Women with polycystic ovary syndrome (PCOS), a condition characterized by hormonal imbalances and irregular periods, also have a higher risk of miscarriage.
A Tommy’s study recently concluded that having lower levels of lactobacillus (good bacteria) in the vagina carries an increased risk of first trimester miscarriage. They also concluded that imbalances with the gut microbiome carry a higher chance of first trimester miscarriage due to higher inflammation levels.
Certain immunological disorders can also be reasons for recurrent miscarriage. Antiphospholipid syndrome (APS), an autoimmune disorder where the body mistakenly attacks normal proteins in the blood, is one such condition that significantly increases the risk of recurrent pregnancy loss.
In addition, some women may have an unusually high level of natural killer cells in their endometrium (the lining of the uterus). These cells are part of the body’s immune system and can potentially attack the embryo if their levels are too high.
While not as common as other causes, certain lifestyle factors can contribute to repeated miscarriages. These include smoking, excessive alcohol consumption, use of recreational drugs, high caffeine intake, obesity, and extreme levels of stress.
The reasons for recurrent miscarriage are varied and often complex. However, with appropriate testing and treatment, many couples with a history of recurrent losses can go on to have successful pregnancies. If you’ve experienced two or more consecutive miscarriages, it’s important to seek help from a healthcare provider who specialises in reproductive medicine. They can guide you through the process of identifying potential causes and developing a treatment plan tailored to your specific needs.
Often the NHS support for recurrent loss is lacking and testing can be limited due to poor resources. At The Fertility Suite we offer 1:1 Fertility and Miscarriage assessments to talk you through the range of testing and treatments available for you and support you in getting the answer you need.
Remember that while experiencing recurrent miscarriages can be incredibly painful and frustrating, you’re not alone. Many resources and support groups can provide emotional support and guidance during this challenging time such as The Worst Girl Gang Ever and Tommy’s.