Overview

Thyroid hormones profoundly affect reproductive health. Both hypothyroidism and hyperthyroidism can disrupt menstrual cycles, impair ovulation, and increase miscarriage risk. Thyroid disorders are among the most common and most easily treated causes of fertility problems.

Symptoms

Hypothyroidism: Fatigue, feeling cold, weight gain, heavy or irregular periods, constipation, dry skin, hair loss, depression, brain fog, elevated prolactin causing anovulation.
Hyperthyroidism: Unexplained weight loss, palpitations, heat intolerance, light or absent periods, anxiety, tremor, insomnia.

Fertility & Pregnancy Complications

• Anovulation — disrupts the hormonal axis controlling ovulation
• Recurrent miscarriage — even subclinical hypothyroidism raises risk
• Preterm birth and placental problems
• Impaired foetal neurodevelopment
• Preeclampsia and gestational hypertension

Diagnosis

• TSH — most sensitive test; should be below 2.5 mIU/L when planning pregnancy
• Free T4 and Free T3
• Anti-TPO antibodies — identify autoimmune thyroid disease
• Thyroid ultrasound

Treatment

• Levothyroxine — for hypothyroidism; dose adjusted carefully in fertility treatment and pregnancy
• Antithyroid medications (carbimazole, PTU) — for hyperthyroidism
• Close monitoring during pregnancy — requirements increase significantly in the first trimester

Not sure if your thyroid is affecting your fertility? Book a consultation today