Trying for a baby but not conceiving? Doctor explains how your thyroid could be playing a bigger role than you think

There are few things more emotionally exhausting than waiting for a pregnancy test to turn positive month after month. For many women, the answers are not always obvious. Sometimes the body gives subtle signs, fatigue that refuses to go away, sudden weight gain, hair fall, irregular periods, or feeling unusually cold. These symptoms are often ignored or blamed on stress. But in many cases, the thyroid gland may quietly be struggling.


As May 25 marks World Thyroid Day, fertility specialists say thyroid health deserves far more attention, especially among women trying to conceive.






The thyroid may be small, but it plays a powerful role in reproductive health. When the gland slows down, hormones that control ovulation and menstruation can become disrupted too. The result is often delayed conception, irregular cycles, or repeated fertility struggles that leave women confused and emotionally drained.


Dr. Alimileti Jhansi Rani, Fertility Specialist at Birla Fertility & IVF Hyderabad, says, “For women trying to conceive, thyroid function is one of the more frequently overlooked variables in the fertility picture.”


In India, thyroid disorders among women are becoming increasingly common. Government-backed research published through the Indian Council of Medical Research (ICMR) and studies indexed by the National Library of Medicine (NIH) have repeatedly highlighted the growing burden of hypothyroidism among women of reproductive age.

The thyroid affects fertility more deeply than most women realise

Many people think the thyroid only controls metabolism or body weight. But fertility specialists say its influence stretches much further.


“The thyroid’s influence on reproductive function runs deeper than most women expect,” says Dr Rani. “Hypothyroidism contributes to infertility by disrupting multiple reproductive processes, including follicular development, fertilisation, embryo implantation, and hormonal regulation.”


In simpler terms, the body may stop preparing healthy eggs properly. The ovaries may not receive the right hormonal signals. Ovulation can become delayed or absent entirely.


Dr Rani further explains, “Low thyroid hormone disrupts the hypothalamic-pituitary-ovarian axis, meaning the brain does not send the right signals to the ovaries.”


This is why many women with hypothyroidism experience longer cycles, unpredictable periods, or skipped menstruation. Even women who continue to menstruate every month may not be ovulating regularly.


And without ovulation, conception becomes difficult.


Research available through the National Center for Biotechnology Information (NCBI) has also linked untreated hypothyroidism with infertility, miscarriage risk, and pregnancy complications.

Why “normal” thyroid levels may still not be ideal for pregnancy

One of the biggest misconceptions around thyroid care is that “normal” reports always mean everything is fine.


For women trying to conceive, specialists often look for thyroid levels that are not just normal, but optimised for fertility.


“One of the more important clinical distinctions for women trying to conceive is the difference between a thyroid result that is normal by standard laboratory criteria and one that is optimised for fertility,” says Dr Rani.


According to her, many fertility specialists prefer keeping TSH levels below 2.5 mIU/L in women planning pregnancy because even slightly elevated levels can affect ovulation and implantation.


Dr Rani notes, “Women with known hypothyroidism treated with levothyroxine before conception should plan to increase their dosage by 25 to 50 percent in the first trimester.”


However, doctors stress that medication changes should never happen without medical supervision.

Fertility support begins with small but consistent changes

One of the most comforting things about thyroid-related fertility issues is that many women respond very well to treatment once the condition is identified properly.


“For women trying to conceive with a known hypothyroidism diagnosis, the most direct intervention is optimising TSH to the fertility-specific target under the guidance of an endocrinologist or fertility specialist,” says Dr Rani.


Alongside medication, daily lifestyle choices also shape hormonal health.


She explains, “Lifestyle factors including selenium-rich foods, adequate iodine intake, and managing chronic stress all support thyroid function.”


But specialists warn against blindly following social media trends around “thyroid healing.” Excess supplements, detoxes, or unverified herbal remedies can sometimes worsen the condition.

Instead, doctors usually encourage:

1. Taking thyroid medication regularly and on an empty stomach
2. Sleeping well to support hormone repair
3. Including iodine and selenium through balanced meals
4. Managing stress levels consistently
5. Avoiding smoking and excessive alcohol
6. Monitoring menstrual and ovulation patterns carefully

Thyroid antibodies can matter even when reports look fine

Some women continue facing miscarriages or fertility struggles despite having thyroid levels that appear normal on paper. In such cases, doctors may look beyond TSH and test for thyroid antibodies.


“Women with elevated thyroid peroxidase antibodies carry a higher risk of miscarriage and pregnancy complications even when TSH is within the normal range,” says Dr Rani.


These antibodies suggest an autoimmune thyroid condition where the immune system mistakenly attacks the thyroid gland.


Identifying this early can help doctors monitor pregnancy more closely and reduce complications later.

Knowing when to seek fertility help can save valuable time

Many women spend years trying naturally while assuming thyroid medication alone will solve the problem. But fertility experts say prolonged waiting may delay diagnosis of other underlying conditions.


“Women with hypothyroidism who have been trying to conceive for six months or more without success warrant a full fertility evaluation,” says Dr Rani.


She explains that thyroid disorders often coexist with conditions like PCOS, reduced ovarian reserve, or uterine abnormalities.


This is particularly important for women in their 30s, where fertility naturally begins to decline with age. Early intervention often improves outcomes and reduces emotional stress later.




Medical experts consulted

This article includes expert inputs shared with TOI Health by:

Dr Alimileti Jhansi Rani, Fertility Specialist, Birla Fertility & IVF, Hyderabad.

Inputs were used to explain how hypothyroidism can affect fertility in women and what steps may help improve the chances of conception through proper thyroid management and medical guidance.