January 22, 2026
Thyroid Disorders and Infertility: How Hormones Affect Fertility
Thyroid hormone imbalances, including hyperthyroidism and hypothyroidism, disrupt ovulation and increase miscarriage risk, directly impacting fertility. Dr. Jessica Selter explains that untreated thyroid conditions can hinder conception and recommends hormonal testing for unexplained infertility cases. Women over 35 with 6 months of infertility or two miscarriages should seek thyroid evaluation.
Key Takeaways
Hyperthyroidism and Hypothyroidism’s Impact on Fertility
Overactive (hyperthyroidism) or underactive (hypothyroidism) thyroid conditions create hormonal imbalances that interfere with ovulation and implantation. Research shows these disorders directly correlate with infertility rates due to disrupted metabolic processes and reproductive signaling.
Low Thyroid Hormones and Ovulation Failure
Inadequate thyroid hormone levels prevent egg release (ovulation), making conception impossible. Underactive thyroid also increases miscarriage risk by 30-40% compared to women with normal hormone levels, according to clinical studies cited in the article.
Thyroid Disorders & Unexplained Infertility Cases
Up to 15% of unexplained infertility cases may actually stem from undiagnosed thyroid conditions. SGF physicians recommend comprehensive thyroid testing for all fertility evaluations, including TSH and free T4 measurements.
Critical Signs to Seek Thyroid Evaluation
Schedule testing if experiencing irregular cycles, two or more miscarriages, or infertility lasting 12+ months (6+ months if age 35+). Family history of thyroid disease is also a key red flag for potential fertility impacts.
Treatment Pathways for Thyroid-Related Infertility
Medications like levothyroxine restore normal hormone levels in 85-90% of cases, often resolving fertility issues within 3-6 months. Persistent cases require consultation with a reproductive endocrinologist to explore additional infertility factors.
Source: Read full article