Thyroid Health Negatively Affecting Fertility

When it comes to fertility, most people think about age or menstrual cycles, but your thyroid plays a huge role too. A precise national prevalence of thyroid disorders in India is not available, still research on infertile Indian women revealed a notable overlap, with hypothyroidism being present in roughly 28% of them and thyroid antibodies that may affect fertility in 8–30% of them.

Thyroid is a tiny butterfly-shaped endocrine gland in your neck that makes T3 and T4 hormones, which regulate your energy, growth, metabolism, and even reproductive factors.  Thyroid dysfunction equally affects fertility in both men and women.  The ability to conceive can be impacted by problems such as increased prolactin levels and irregular menstruation, which can be caused by either hyperthyroidism or hypothyroidism.

Importance of Thyroid hormones in fertility

Thyroid hormones are closely linked to reproductive hormones like estrogen, progesterone, and luteinizing hormone (LH). It influences the production of sex hormone-binding globulin (SHBG) and prolactin, which regulate menstrual and reproductive health. Elevated prolactin levels, often seen in hypothyroidism, can suppress ovulation and contribute to infertility.

In women, these hormones regulate the hypothalamic-pituitary-ovarian (HPO) axis, influencing the release of FSH and LH that control the menstrual cycle, imbalances in it can lead to irregular periods or amenorrhea, affecting ovulation. They also act directly on the ovaries, supporting follicular development and , while ensuring proper endometrial growth and receptivity for embryo implantation and maintaining the hormonal balance needed for a healthy pregnancy.

In men, thyroid hormones are vital for sperm production and testicular function, with hypothyroidism often linked to abnormal sperm morphology and reduced semen quality, ultimately affecting fertility potential.

Underactive Thyroid (Hypothyroidism) Versus Overactive Thyroid (Hyperthyroidism)

Hypothyroidism slows down the metabolism and can lead to irregular or absent periods, anovulation, elevated prolactin, and higher risks of miscarriage and preterm birth in women, while in men it may reduce libido and sperm quality. Hyperthyroidism accelerates metabolism and can cause lighter or infrequent periods, impaired ovarian function, and difficulties with embryo implantation in women, as well as reduced sperm count and motility in men.

Thyroid dysfunction affects the hypothalamic-pituitary-gonadal axis.

Thyroid tests that can help to diagnose

A simple blood test measuring TSH, T3, and T4 levels can reveal if your thyroid is out of balance. Though these tests are simple, it can be quite helpful to figure out solutions quickly.

How to manage thyroid for better fertility

Thyroid related issues can be manageable if detected on time and a proper routine is followed. Thyroid hormone replacement for hypothyroidism or anti-thyroid therapy for hyperthyroidism, are some treatments which can help to restore reproductive health and improve chances of conception. Here, are some ways to manage thyroid:

1. People with thyroid problems should continue their medications as advised by doctors. As it can help to regulate hormonal levels.
2. Following a healthy lifestyle which includes a balanced diet, exercise, and managing stress are crucial. People should avoid consuming certain vegetables and fruits that can negatively affect your thyroid.
3. Thyroid should be monitored regularly, so that they have a track of the levels. The thyroid hormones should be kept under optimal range before and during pregnancy.

(Dr. Priyanka Dilip Kumar, Consultant – Gynecologist, Obstetrician & Reproductive Medicine, Milann Fertility Hospital, Bengaluru)