Hormonal Changes throughout your cycle.
The vaginal microbiome changes throughout the menstrual cycle and becomes a very different environment just before the menstrual bleed.
The main reason for this is the fluctuation in sex hormones, namely oestrogen. Oestrogen reaches its highest concentration just before ovulation, about halfway through the cycle.
Oestrogen increases glycogen (a storage form of glucose) in the cervical fluid, making it more sticky and alkaline and therefore, a more suitable environment for yeast and bacteria to thrive.
This is when we are most prone to vaginal infections, especially if you are already prone to something like thrush or BV.
Menstrual changes to the microbial environment.
If you manage to avoid a vaginal infection during the luteal phase, menstruation brings its own challenges.
During the bleed, the vaginal microbiota is most vulnerable to bacterial changes, as menstrual blood moving through the vaginal canal brings different species of microorganisms with it, which may throw out the balance of beneficial bacteria.
Changes toVaginal Ph.
Menstrual blood also has a higher pH level, of about 7.4, which raises the pH level of the vagina again, causing more alkalinity.
If you are prone to vaginal infections around your period, it may be useful to track your pH throughout your cycle to gain a better idea of how your hormones may be affecting the microbial environment of your vagina!.