When people talk about female fertility and reproductive health, it’s often in the context of reproductive ‘ill-health’ and how to improve it. For many, the advice they’re given comes in the form of making some lifestyle changes, such as improving diet and activity levels and reducing stress. But how do these lifestyle changes actually impact reproductive function and whether or not you regularly ovulate? How is it that improving nutritional health and reducing stress impact what’s happening in your ovaries?
While your ovaries are indeed important when it comes to reproductive function and are the home of both hormone production (i.e. oestrogens and progesterone) and egg development, they are nevertheless at the tail end of the reproductive ‘chain of command’. Reproductive function is in fact governed by the brain. The brain coordinates the release of hormone pulses, and the rhythm of these hormone pulses ultimately directs ovarian function. Therefore, improving reproductive health often means improving the brain’s coordinated release of these hormone pulses, and to do that, we need to understand what impacts their release.
Even though reproductive function is critical for species survival, under certain environmental, physiological or psychological conditions, suppressing reproduction becomes an adaptive survival response. For example, when there isn’t sufficient energy available to support the high demands of pregnancy, lactation and child-rearing, reproductive function will be suppressed to conserve energy for vital functions. Similarly, reproductive function will be suppressed during times of high perceived stress or psychological trauma, or when immune stress is high, which also indicates it’s an inopportune time to reproduce. This means that signals related to nutritional status, environmental conditions, physical and emotional wellbeing, etc. need to be communicated to the reproductive ‘control centre’ in the brain to ensure reproduction only occurs when conditions are favourable.
Evolutionarily, this meant reproductive function was suppressed during times of famine, or war, or illness—it was a perfectly adaptive response to the unfavourable conditions. Today, the infertility associated with this type of reproductive suppression often appears to be maladaptive. Our modern perceived stresses are often psychosocial stresses, like work and relationship stress, or even the stress of infertility itself. And our modern metabolic stress is often not starvation, but rather obesity. While it doesn’t appear helpful for these modern day ‘stressors’ to suppress our fertility, their physiological signatures in the brain are no different from the more threatening stressors that we would want to cause reproductive suppression. Therefore, optimising wellbeing, minimising stress and balancing metabolism is often the first line of treatment for individuals presenting with menstrual dysfunction or infertility.
Polycystic ovary syndrome (PCOS), despite what the name suggests, also involves the reproductive control centres of the brain. Research suggests that the normal communication of signals to the brain’s reproductive control centres are impaired in PCOS. In women with PCOS, impaired fertility is usually not a result of adaptive fertility suppression, but due to other underlying causes and unknown aetiologies. Trying to understand these origins and mechanisms of PCOS remains an active area of research.
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