Reoccurring Miscarriages: Can Progesterone Be To Blame?

Progesterone and estrogen work in ratio of each other, and one influences another. There is a lot of information out there about estrogen balance, and what this means for your health, but progesterone levels are broadly overlooked in general reading. 

Estrogen dominance is not always due to high estrogen, it can very well be because of low progesterone (hence leaving estrogen as “dominant”). Believe it or not, I actually see low progesterone in lab test results in 90% of women in my private practice! Low progesterone means that your sex hormones are imbalanced, and when you have low progesterone it is more difficult to conceive. This is not just an issue when you are trying for a baby; if you have low progesterone during pregnancy, you are more likely to experience a miscarriage. 


Do you track your menstrual cycle? Your sex hormones regulate your menstrual cycle, but this does not mean that they are at consistent levels throughout the cycle. For example, progesterone rises after ovulation and should stay elevated throughout your luteal phase. This should last about 8 days (but everyone is different) after optimal fertility. Progesterone rises after ovulation, reaching a peak around Day 21 of a 28-day cycle and that is why I ask my female clients to run their comprehensive hormonal test between days 19-21.

Progesterone rises so that it makes the uterine lining ‘sticky’, to optimise implantation. Whilst doing so, it provides nutrients to the uterine lining, so that the environment is optimal for the embryo to thrive. 

If you have low progesterone, the uterine lining is not stabilised and will be a less ‘welcoming’ environment for implantation. This makes conceiving harder.


The corpus luteum maintains the production of progesterone into the first trimester. Between week 7 and 10, the placenta will start to produce progesterone. This production is important to provide nutrients to the foetus. When progesterone is low, there may not be enough nutrients delivered to the growing baby and miscarriage can occur. 

Progesterone is also responsible for delivering oxygen to the foetus, if this is not optimal it can be incredibly damaging to the growth and development of the baby. When progesterone is very low, the baby will not get enough oxygen to survive and the mother will miscarry. 



Women with PCOS tend to have higher androgens, which can prevent ovulation and make it difficult to have regular menstrual cycles. The follicles grow but the eggs do not get released. As a result, ovulation does not occur, thus preventing your body from producing progesterone adequately. 


When the adrenals become depleted (aka adrenal fatigue) from chronic stress, the body is desperate to increase cortisol levels and so begins ‘stealing’ sex hormones, especially progesterone, to produce it (progesterone is a pre-cursor to cortisol). This leads to an estrogen dominant state because there isn’t enough progesterone on-board. 


Progesterone and thyroid hormones have a reciprocal relationship; the body needs adequate amounts of thyroid hormone for the ovaries to make progesterone, but it also needs adequate amount of progesterone for optimal thyroid function.


If the body is not balanced because it’s either under- or overweight, progesterone levels are likely to drop. Why? Well, the body is very smart, if the environment on the inside is not appropriate and healthy for a baby, it will simply not allow for reproduction.


Are bioidentical hormones the solution? Of course not. As I always say, you need to work out WHY you have low progesterone levels in the first place. There are lots of ways that people try to balance their hormones: seed cycling, supplements, diet. But if you don’t know what is really going on within, your attempts may have no effect, or could even cause more damage! 

At-home functional lab tests will indicate your hormone levels, and their ratio to each other andlook at adrenal issues, toxins and nutrient deficiencies. Once you have identified the underlying root cause for your low progesterone levels, you can start a specific protocol to help you heal and rebalance. 




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