How thyroid imbalances can affect fertility in both men and women? Know about thyroid health for successful conception and pregnancy.
Thyroid health plays a role in fertility, as imbalances like hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can impact reproductive function. These thyroid conditions disrupt the balance of reproductive hormones, menstrual cycles, and ovulation, thereby affecting fertility. Often, women may not notice these disorders, but they can lead to infertility and repeated miscarriages. In India, approximately 20% of female infertility cases are due to thyroid issues, according to the Journal of Evidence-Based Medicine and Healthcare.
Thyroid problems not only affect weight, energy levels, and mood, but also the immune system. “The thyroid gland plays a role in the body’s hormone system. When thyroid levels are too high or too low, it doesn’t stay limited to one gland. Instead, it disrupts multiple hormones related to ovulation, menstrual regularity, sperm health, and overall fertility,” Dr Sonal Singhal, Obstetrician and Gynaecologist, Motherhood Hospital, Gurgaon, tells Health Shots. This is why untreated or poorly controlled thyroid imbalance is a common but often missed cause of fertility issues.
How do thyroid issues affect hormones?
The thyroid works closely with the brain, ovaries, testes, pancreas, and adrenal glands. “When thyroid hormones are imbalanced, the brain sends confused signals to other hormone-producing organs. Hence, one of the first hormones affected is prolactin,” says the obstetrician. Low thyroid levels can increase prolactin, which may block ovulation in women and reduce sperm production in men.
High prolactin can also cause irregular periods or missed cycles and impact fertility. Hence, women will find it difficult to conceive. “Then, even estrogen and progesterone, the key female reproductive hormones, are affected due to thyroid imbalance”, says the gynaecologist. Thyroid imbalance can lead to estrogen dominance or low progesterone.
This results in irregular periods, heavy bleeding, difficulty in ovulation, and problems with implantation, making pregnancy harder to achieve and sustain. Insulin is also affected by thyroid health. “A thyroid imbalance can increase insulin resistance, leading to higher blood sugar levels”, says Dr Singhal. This hormonal disturbance can worsen insulin resistance and contribute to conditions like PCOS, which is a cause of infertility in young women across the country.
How does cortisol affect thyroid hormones?
Even cortisol, a stress hormone, plays an important role in thyroid dysfunction, which can put stress on the body and raise cortisol levels. “High cortisol interferes with ovulation, reduces egg quality, lowers sperm count, and affects libido,” says the expert. So, stress further worsens thyroid imbalance, creating a vicious cycle.
- Fertility health is compromised: Because of this hormonal chain reaction, couples may struggle with delayed conception, repeated miscarriages, irregular cycles, low sperm count, or poor embryo quality. “Many individuals tend to appear healthy on the outside but have underlying hormonal disruptions driven by thyroid imbalance that can become a matter of concern and lead to difficulties while conceiving”, says the doctor.
- Why early testing and treatment matter: Do blood tests to detect thyroid dysfunction early. “Following the doctor’s treatment plan, managing stress with yoga and meditation, sleeping well for 8-9 hours nightly, maintaining a balanced diet, and addressing insulin resistance can help restore hormonal balance and fulfil the dream of pregnancy” shares the expert. Many individuals are told their thyroid levels are “normal,” yet for fertility, optimal TSH levels are often lower. Even a mild thyroid imbalance can interfere with conception and pregnancy outcomes. So, prioritise your thyroid health and prevent fertility issues.
- Thyroid imbalance affects men too: it can reduce the sperm count, motility and testosterone levels, contributing to unexplained male infertility. Fertility, overall, is rarely about a single hormone; it’s about balance. “Since the thyroid sits at the centre of this hormonal network, even subtle imbalances can create widespread disruptions”, explains the doctor. Early testing, personalised treatment, stress management and metabolic correction can help restore hormonal harmony and improve fertility outcomes. Prioritising thyroid health is not optional-it is essential for those planning a family.
