Likewise, the current guidelines for detection and management of hypothyroidism both in pregnancy and in women with infertility are complex, confusing and conflicting.
There are three types of thyroid disorder:
- Hyperthyroidism – hyper activity of the thyroid gland
- Hypothyroidism – underactivity of the thyroid gland
- Thyroid autoimmunity (TAI)
Signs and Symptoms in each of these cases:
| Hypothyroidism | Hyperthyroidism |
| Hair Loss | Hair Loss |
| Dullness | Exophthalmos |
| Goiter | Goiter |
| Reduced heart rate | Palpitations |
| Fatigue | Tremors |
| Cold insensitivity | Heat Intolerance |
| Dry Skin | Sleep Disturbances |
| Weight Gain | Weight Loss |
| Memory problems | Shortness of Breath |
| Constipation | Diarrhoea |
| Irregular menses | Increased Appetite |
| Depression | Irregular Menstruation |
| Mood Swings | Muscle Weakness |
| Sweating | |
| Anxiety / Nervousness |
Hypothyroidism in Male Infertility
- Increase in SHBG
- Total and free estradiol concentration often elevated
- Increase in total testosterone
- Metabolic clearance rate is decreased
- Free testosterone to free E2 ratio is lower
- Contributes to the increased incidence of gynecomastia with decreased libido
Note: Less common in men than in women. Effects on reproductive function not well delineated.
Clinical Manifestation related to Fertility
- Erectile dysfunction incidence up to 70%, correctable after correction of thyrotoxicosis
- Spermatogenic abnormalities
- Low total sperm count 43%
- Lineal motility defects 86%
- Progressive motility abnormal 62%
Radioiodine (RI) remains the mainstay of treatment. Reproductive performance remains normal in men after RI therapy.
Thyroid Cancer and Fertility
The different types of thyroid cancer and treatment modalities are beyond the scope of this chapter. However, the effect of prior thyroid cancer and treatment on fertility is a matter of concern.
RAI treatment in cancer has its effects on reproduction. RAI causes transient amenorrhea in up to 27% of women and slightly earlier menopause. In men, RAI causes transient increase in FSH and reduction of normokinetic sperms.
Thyroid Autoimmunity
- The prevalence of TAI is 5-10 times higher in females than males, and this is due to various factors like genetic factors, oestrogen related effects, and chromosome X abnormalities. It is most common autoimmune disorder in women, affecting 5-20% in women of reproductive age group.
- Most studies so far have showed a higher prevalence of TAI in women visiting fertility clinics, specially so among infertility women with endometriosis, polycystic ovarian syndrome and premature ovarian failure.
- An increased prevalence of TAI is reported in women with recurrent pregnancy loss and subfertility and associated with lower anti mullerian hormone (AMH) levels.
Results?
- Female hypothyroidism is a very common condition and management of the same is ever evolving, hence updating evidence is very critical.
- Thyroid disorders tend to be silent and vouge, routine testing is as per guidelines and correction of thyroid function is vital for good fertility outcome.
- Further robust studies are required to elucidate the relevance of thyroid autoimmunity and its management in euthyroid women and in SCH.
Key points addressed in the article:
- Three common thyroid disorders that can have an effect on female and male fertility are hypothyroidism, hyperthyroidism and TAI.
- Menstrual irregularities are common in both hypothyroidism and hyperthyroidism.
- Most hyperthyroidism women tend to have ovulatory cycles.
- Clinical hypo and hyperthyroidism require to be corrected.
- SCH is defined as TSH values above 2.5 mlU/L and normal FT4 levels with TAI, treatment needs to be started with LT4 when aiming for pregnancy.
- The ETA 2021 guidelines suggest that euthyroid women with TAI undergoing IVF/ ICSI should be treated systematically with LT4.
- Hyperthyroidism in men is associated with erectile dysfunction in up to 70%, which is reversible posttreatment.
- The most common parameter of semen analysis is affected with hyperthyroidism is linear motility (86%)
- Hypothyroidism in men is associated with decreased libido or impotence.
- Hypothyroidism can have an adverse effect on human gametogenesis with possibly sperm morphology being affected the most.
Thyroid disorders plays an important role in reproductive health, affecting both male and female fertility. Conditions like hypothyroidism, hyperthyroidism, and thyroid autoimmunity (TAI) can lead to menstrual loopholes, ovulation difficulties, erectile dysfunction, and poor sperm quality. Given the increasing frequency of thyroid abnormalities, their diagnosis and management are crucial for improving fertility outcomes. This is particularly relevant for reproductive medicine specialists, who need to stay updated on evolving guidelines for thyroid screening and treatment in infertility cases.
The Hybrid Fellowship in Reproductive Medicine offered by Medline Academics in Bangalore provides complete training for clinicians focusing in fertility treatment. This program trains mentees with the up-to-date knowledge and hands-on experience in managing multifaceted cases, including those related to thyroid disorders and infertility.
The curriculum for Fellowship in Reproductive Medicine in India is designed to link academic learning with clinical practice, ensuring that specialists are well-prepared to handle conditions like hypothyroidism, hyperthyroidism, and TAI in patients undergoing fertility treatments such as IVF and ICSI. With mentorship from top faculties and access to advanced reproductive skills, this FRM program enhances the skills of aspiring reproductive medicine practitioners, ultimately improving patient care and fertility success rates.