1300 21 44 25

How your Thyroid Function can impact Fertility

How your Thyroid Function can impact Fertility

Have you been trying unsuccessfully to have a baby for some time?
It might be a good idea, along with other standard preconception tests, to have a comprehensive thyroid test done to check and ensure that it is functioning at its best.

Good thyroid function is necessary for both male and female fertility, the ability to conceive and to maintain a pregnancy and for the health of the baby. Unfortunately, many GPs and fertility specialists rarely include comprehensive thyroid testing as part of a preconception assessment.

An under or over functioning thyroid can prevent you from falling pregnant. While there are many reasons for infertility, suboptimal thyroid function may be that “missing link” especially for those with no specific reproductive problems and have been diagnosed as having “unexplained infertility”.

What Does the Thyroid Gland Do?

The thyroid is a small butterfly shaped gland located near the front of the throat. The purpose of the thyroid gland is to take iodine from foods that we eat and convert them into thyroid hormones: thyroxine (T4) and triiodothyronine (T3). The thyroid combines iodine and the amino acid tyrosine to make T4 and T3. T4 and T3, once released into the blood stream control our metabolism.

The thyroid is also responsible for regulation of blood calcium levels, energy production, fat metabolism, balance of hormones, the gastrointestinal system, and weight management.

How Does Poor Thyroid Health Affect Fertility?

Poor thyroid function upsets your body’s natural balance of reproductive hormones.

For Women

Thyroid problems can lead to irregular menstrual cycles or even the absence of menstruation altogether (amenorrhoea). Some cycles you may not ovulate because of the effect of thyroid hormones on reproductive hormones. If no egg is released, then pregnancy is not possible.

If the second half of your menstrual cycle is too short due to insufficient response of luteinising hormone with thyroid hormone there will not be enough progesterone production meaning that a fertilised egg wont securely implant and will be miscarried.

Low thyroid function will also result in a low basal body temperature. The rapidly dividing cells of the body and of a little embryo require a specific temperature range for that division to take place. If your basal body temperature is too low, the embryo may be unable to continue to grow which increases the risk of miscarriage.

Low levels of thyroid hormones can also result in an excess of prolactin (normally produced to promote lactation) which will have a negative effect on fertility and can prevent ovulation or result in irregular or absent periods.

Other hormonal imbalances, due to thyroid dysfunction, such as oestrogen dominance and progesterone deficiency can interfere with proper reproductive hormone balance. Oestrogen dominance can suppress thyroid function.

For Men

It is equally important for men to prepare for a healthy pregnancy as it is for women. The importance of thyroid function for male fertility can’t be underestimated. The thyroid directly affects sperm production as there are many thyroid hormone receptors on the steroli cells. This directly influences sperm production and motility.

Poor thyroid function can also result in reduced testosterone production, a lower libido, erectile dysfunction, poor testicular function, as well as reduced sperm numbers and motility. It can also lead to increased levels of oxidative stress which can have an impact on DNA integrity and the form of the sperm.

Pregnancy risks

If the thyroid problems are undiagnosed and untreated this can lead to a worsening of pregnancy problems such as increased risk of miscarriage, morning sickness, fatigue, depression, hair loss, inter uterine growth retardation, and pre-term labour.

For your baby, poor thyroid function in the mum can put the baby at risk of impaired growth and development of the sex organs and cognitive problems and brain development in the baby.

What Factors Can Impact Thyroid Health?

The following factors can impact your thyroid health.
• High perceived levels of stress
• Nutrient deficiencies
• Infections
• Autoimmune disorders
• Genetic predisposition
• Exposure to environmental toxins – electromagnetic radiation, chemicals, pesticides, heavy metals e.g. mercury & fluoride (e.g. in water supply or toothpaste)
• Other hormone imbalances e.g. oestrogen dominance, high prolactin levels

So, what can you do to reduce the impact on your thyroid health?

Reduce your consumption of refined grains and simple sugars, soy products, caffeine, cigarette smoke and alcohol. Reduce your exposure to heavy metals e.g. mercury (amalgam fillings) and fluoride (water supply, toothpaste) as well as bisphenols in plastics as these may also be detrimental to thyroid health.

Managing your perceived levels of stress is crucial. Stress results in elevated levels of cortisol, the main hormone released by the adrenal glands. Increased cortisol will inhibit the conversion of T4 to the active T3 hormone and will stop the active T3 entering cells sufficiently.

Exercise is extremely beneficial as it will stimulate thyroid hormone secretion and increases tissue sensitivity to thyroid hormones.

Treating and supporting the thyroid function is one piece in the complex puzzle of fertility issues.


Nicole Haak is an experienced Melbourne Naturopath whose gentle approach and warm nature enable her to be an empathetic and supportive practitioner who takes a genuine interest in her clients’ needs. She has a deep passion for what she does. This is evident by her holistic approach to helping her patients find solutions to their health concerns and improve their quality of life.

0 comments

Leave a comment