Unexplained infertility is one of the categories of infertility diagnoses that I have had great success in the clinic. Did you know that the modern medical term “Unexplained Infertility” is applied to women who are often misdiagnosed? If all of your tests have come back normal so far, the missing pieces have simply not yet been discovered. This where a change of perspective is helpful to examine other areas that may be impeding your fertility.
This article will outline some of the more common causes of ‘unexplained infertility’, and a brief description of each, along with how to test or assess. Although there are still some cases that remain unexplained, I have found that the following list of possibilities has resulted in many pregnancies.
- Hidden hypothyroidism or borderline thyroid function: In many cases, hypothyroidism, or low thyroid function is improperly diagnosed, especially if only a TSH level is measured. A borderline-high TSH level, poor conversion of free T4 to free T3, or the presence of thyroid antibodies alone can result in difficulty conceiving or miscarriage.
- Endometriosis: This is the most common cause of unexplained infertility, and in some cases endometriosis is suspected based on typical symptoms, such as very painful menstruation, pain leading up to menstruation, painful intercourse and diarrhea with the period; but in other cases it is quite hidden with very few symptoms. Endometriosis causes significant pelvic inflammation which can affect fertility from a structural perspective with scarring and adhesions, but can also affect implantation because of immune system factors and inflammation.
- Atypical polycystic ovarian syndrome: Most people are aware of the fertility struggles of women with typical polycystic ovarian syndrome, but there are atypical cases where, for example a thin women with slightly irregular periods, and moderate acne has many other markers of polycystic ovarian syndrome, but the diagnosis is missed simply based on a normal body weight. Polycystic ovarian syndrome can cause difficulty conceiving not only due to irregular ovulation, but also due to other factors such as a thickened outer layer (zone pellucida) of her eggs, a tendency for associated thyroid imbalance, and higher likelihood of methylation problems (read below).
- Autoimmune causes: In women with autoimmune disorders, the immune system is dysregulated, and can result in immune issues related to fertility also. If the immune system is over-active, it may affect the body’s response to sperm or even an implanted embryo, causing rejection. If there is a family history of autoimmune disorders (including thyroid disorders), presence of allergies / eczema / asthma, or a person history of autoimmune disorders, treating the immune system and lowering inflammation through diet and with supplements is necessary to improve fertility.
- Luteal phase defect or low progesterone: Luteal phase defect refers to either a short luteal phase (10 or less days after ovulation), or low / unstable progesterone in the luteal phase. In both cases, implantation of the embryo into the uterine lining is impaired. Progesterone can be tested with a simple blood test mid-luteal phase to check that it is in an optimal range; and luteal phase stability is best seen through basal body temperature charting, where fluctuations in temperature can indicate fluctuations in progesterone.
- Egg quality issues: We are accustomed to seeing egg quality issues in women over 40, but in some cases the quality of the eggs changes prematurely. This may show up as abnormalities in bloodwork: a slightly high day 3 FSH, or a low AMH (marker of ovarian reserve). I have seen frequent x-rays (even in early childhood) and radiation exposure through frequent travel as possible causes. Mild egg quality issues can be addressed however with high-dose antioxidant supplements, along with Chinese herbs and acupuncture.
- Stress hormone imbalance: Stress alone is rarely a stand-alone cause of infertility, but it can amplify anything else that is out of balance. For example, high stress hormones (cortisol and DHEA) can worsen PCOS symptoms; and on the other end of the spectrum, low stress hormones due to prolonged high stress can accelerate egg-quality decline in the late 30’s and early 40’s. Stress hormones can be tested through both saliva and blood tests.
- Blood clotting disorders: Blood clotting disorders can be either genetic or autoimmune, and are associated with an increased risk of forming blood clots that can interfere with pregnancy, or more commonly cause miscarriage. Common genetic disorders are “factor V Leiden” and “prothrombin mutations”, and autoimmune causes can include Lupus anticoagulants, which are antibodies that attack substances that the body normally produces to prevent blood clotting. These can be tested for with specialized blood tests, and are indicated in cases where there is a family history of blood clots, and also in cases of frequent miscarriage.
- Problems with methylation: Methylation is a chemical process that occurs in the body to repair DNA, detoxify, reduce inflammation and lower homocysteine levels. One key fact about methylation is that we require B-vitamins, and specific forms of B-vitamins to methylate properly. The problem is that some people do not methylate properly, as 20% or more of the population carry a genetic flaw affecting methylation. Other causes of poor methylation include: poor diet, poor digestion, smoking, low stomach acid, and certain medications which affect B vitamin absorption. There is testing for the genetic causes of poor methylation, especially for “MTHFR” gene mutation. The relevance for fertility is methylation disorders are associated with infertility, miscarriage, neural tube defects in babies and pre-eclampsia.
- Cervical mucous incompatibility / hostility: The quality of cervical fluid is also essential for fertility, and can be affected by infection, stress, immune system. hormone balance and nutrition. The first step in optimizing cervical fluid quality, is testing for and treating infections – even chronic yeast infections can affect cervical fluid quality.
This article was intended as a quick overview of some of the issues I am looking for and assessing in cases of unexplained infertility. I hope that this acts as a starting point for further investigation and treatment for you, if you have received this frustrating diagnosis. There is often so much that can be done to support fertility once we understand what is blocking it.