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New Study from Harvard Finds That the Thyroid Can Be Responsible for Infertility

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A new study from Harvard Medical School confirms what many doctors have suspected for some time. Low thyroid hormone levels do indeed affect a woman’s fertility and mildly low thyroid hormone levels can be responsible for infertility.


According to the CDC, published in the WomensHealth.gov, infertility affects approximately 10% of American women. However, unexplained infertility affects 10-30% of infertile couples.

Harvard Medical School released the results of a new study on the December 19th, 2017, in which they found that more than a quarter of the women who had unexplained infertility shared another factor: their thyroids were performing on the low end of the normal range as their TSH levels showed.

Thyroid stimulating hormone (TSH) is released by the pituitary to activate the thyroid to release more hormone. An elevated TSH is indicative of an underactive thyroid gland. The thyroid is situated near the base of the throat, and the endocrine gland resembles a butterfly’s outstretched wings in shape.

Underactive and Overactive Thyroids

Dr. Pouneh Fazeli, the study’s senior researcher, said that hypothyroidism affects irregular menstrual cycles which interfere with ovulation and conception. Women with Hashimoto’s Thyroiditis (underactive) and Grave’s Disease (overactive) have been reported to have a 50% increase of infertility rates. All women participants in the study had normal menstruation cycles.

The study was divided into two groups of participants. The first group was composed of 187 couples with unexplained fertility. The second control group was composed of 52 couples in which the male partners had extremely low sperm counts.

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Almost 27% of the unexplained fertility group had a TSH level of 2.5 or greater which is in the high-normal range. To put it into perspective, hypothyroid patients are diagnosed at a TSH of 4.5 or higher. Fazeli reported a comparison of only 13.5% of the women in the male-factor infertility group.

Dr. Alan Copperman, director of reproductive endocrinology and infertility at the Mount Sinai Health System in New York City, said doctors might need to focus on the health problems that are causing low thyroid levels because those might be the true culprit behind infertility. Dr. Copperman wasn’t involved in the study.

Infertility is a broad medical condition with a variety of causes, but this study may prove to be invaluable in showing the link between the thyroid and infertility. Fazeli said that the next step of research involves seeing whether giving women supplements to boost their thyroid hormone levels will make a difference.

Root Causes

Many researchers seek to understand the root cause of thyroid disorders. If you know a loved one with hypothyroidism or another thyroid disorder, I wholeheartedly recommend Dr. Datis Kharrazian’s book “Why Do I Still Have Thyroid Symptoms If My Thyroid Tests Are Normal?” and Dr. Isabella Wentz’s books.

I personally have Hashimoto’s Thyroiditis, and thus I am very excited to see new research being done to support the link between the thyroid and fertility. I believe thyroid disease is very common and prevalent today. We must tirelessly research and understand the thyroid in order to prevent the landslide of symptoms associated with thyroid disease from affecting more of the US population.

Check out these other great articles by EMaxHealth: Why Prenatal Vitamins are Necessary Support for Women, Choosing Fruits and Vegetables Wisely May Help Fertility , and Aggressive Support of Breastfeeding Is Encouraged.