Thyroid and Fertility: How Thyroid Affects Chances of Conceiving?

Komal Chaudhary
May 15
2 min read

Your thyroid— a small butterfly-shaped gland in your neck—controls much more than your metabolism. It plays a crucial role in your reproductive health. Both hypothyroidism (underactive thyroid) and hyperthyroidism (overactive thyroid) can interfere with ovulation, menstrual cycles, and even increase the risk of miscarriage.

Thyroid Hormones and Pregnancy:

TSH (Thyroid Stimulating Hormone): High TSH levels can affect the release of eggs (ovulation).
T3 & T4 (thyroid hormones): Imbalances in these hormones can lead to irregular cycles, hormonal imbalance, or luteal phase defects.

Signs Your Thyroid May Be Affecting Your Fertility

Unexplained weight gain or loss
Irregular or absent periods
Feeling tired or sluggish
Cold hands/feet
Anxiety or mood swings
Hair thinning

If you're experiencing these symptoms while trying to conceive (TTC), it's essential to get your thyroid levels tested.

How Thyroid Affects Pregnancy?

An untreated thyroid disorder can lead to difficulty conceiving, higher risk of miscarriage, preterm birth, and developmental delays in the baby. That’s why checking thyroid levels (TSH, T3, T4) is part of most fertility assessments today.

Before Pregnancy

Hypothyroidism, where your thyroid doesn’t produce enough hormones—can disrupt ovulation entirely or lead to irregular egg release. This happens because low levels of thyroxine (T4) and high thyroid-releasing hormone (TRH) increase prolactin levels. Elevated prolactin can prevent ovulation or shorten the second half of your menstrual cycle, reducing the chances of successful implantation.

Other fertility challenges linked to hypothyroidism include:

Low basal body temperature
Presence of thyroid peroxidase (TPO) antibodies
Ovarian cysts
These issues may result in difficulty conceiving or early pregnancy loss.
Monitor These Before You Conceive

If you’ve had a miscarriage, already have low thyroid hormone levels, or have a family history of thyroid or autoimmune diseases, get your TSH and T4 levels checked before planning a pregnancy. Identifying and managing hypothyroidism early can dramatically improve fertility outcomes

Postpartum Thyroid Issues

Many women develop postpartum thyroiditis within 3–6 months after delivery, especially those with autoimmune thyroid disorders or high TPO antibodies during pregnancy.

It often presents in two phases:

Phase 1:

Irritability
Anxiety
Rapid heartbeat
Sudden weight loss
Heat sensitivity
Insomnia

Phase 2:

Cold intolerance
Fatigue
Constipation
Dry skin
Mental fog Every woman’s experience is different. While postpartum thyroiditis can affect milk supply, the issue usually resolves with hormone therapy.

When to Get Tested

If you've been trying to conceive for over 6 months without success, or if you have irregular periods, a simple blood test for TSH and thyroid hormones can give you answers.

Your fertility is a complex puzzle, and the thyroid is one of its key pieces. If you're unsure whether your thyroid is affecting your chances of getting pregnant, we're here to help.

Kind Fertility offers essential fertility hormone testing—including TSH, Prolactin and AMH right from the comfort of your home and take control of your reproductive health.