"Be Your Own Thyroid Advocate." Rachel Hill is the highly ranked and award-winning thyroid patient advocate, writer, blogger, speaker and author behind The Invisible Hypothyroidism.

As well as complications during pregnancy, some women with low thyroid levels may even struggle to fall pregnant at all.

Hormones TSH (thyroid stimulating hormone) and TRH (thyrotropin-releasing hormone) are ramped up when thyroid hormones such as Free T3 and Free T4 fall too low; TRH to stimulate the pituitary gland to release TSH, which instructs the thyroid gland to release more thyroid hormones T3 and T4.

I am also noticing more and more women with sex hormone issues such as oestrogen dominance, which can affect cycles and ovulation.

Since the thyroid, pituitary and ovaries are all part of the endocrine system, it’s not difficult to see why having problems with one of these, may also mean having issues with another.

It is therefore important to be aware of the effects of low thyroid hormone levels on an unborn child.