Relationship of Menstrual Cycle, Lifestyle, Contraception and Vaginal Microbiome

Vaginal microenvironment plays a vital role in a healthy woman’s sexual and reproductive wellbeing. Often, the alteration and depletion of certain vaginal microbiome such as Lactobacillus spp can be associated with vaginal infections such as recurring yeast infection or bacterial vaginosis. A stable and less diversified microflora with Lactobacillus spp predominance ensures healthy long term vaginal health.

Have you ever wonder why some ladies are more predisposed towards vaginal microflora changes? Even within a same woman, the vaginal microflora can fluctuate with time. Here, we explore on the effects of female hormones, sex, lifestyle, contraception choices on the vaginal microenvironment.

**Vaginal Microbiome Lactobacillus spp During Reproductive Age**

The healthy colonization of vaginal microbiome can be personalized and differs from one another. It is a self-sustaining ‘micro-ecosystem’ that self-regulates, self-cleans, and dynamically change over time due to external factors such as hormone, lifestyle, sex, infections, medications etc. Not unusually, the healthy bacteria that colonizes the vagina can change even over a matter of days.

From the time of puberty into and through adulthood, a healthy vaginal microbiome is predominated by Lactobacillus spp. Furthermore, the amount of Lactobacillus spp increases during pregnancy.

Lactobacillus spp create a low pH microenvironment by production of lactic acid, making the vagina unsuitable for various pathogens and infection. Hence, Lactobacillus spp acts as a vagina defense mechanism against infections. It is currently known that the depletion of lactobacillus spp in the vagina can lead to bacterial vaginosis infections, increases the risk of contracting STDs such as HIV, herpes, chlamydial infections and etc.

Menstrual Cycle Alters Vaginal Microenvironment

Lactobacillus spp typically thrives under the influence of estrogen hormone. During menstruation, due to a cyclical drop of estrogen and rise of progesterone hormones, the amount of Lactobacilus spp decreases and the vaginal microflora becomes diversified leading to increase opportunity of various vaginal bad bacterial colonization, predisposing one towards abnormal vaginal symptoms such as vaginal itch, unusual discharge, discomfort.

Intriguingly, some women’s vaginal microbiome remains stable throughout menstrual cycle, while others may experience temporal and transient shift of the microbiome flora during menses, and bacterial population returns back to normal after period. This is why some women (not all) may experience vaginal infections peri-menstrual period.

Impact Of Irregular Menstruation On The Vaginal Microenvironment

Irregular period, due to conditions such as PCOS (polycystic ovarian syndrome) can be associated with vaginal microbiome disruption with reduced lactobacillus spp and overgrowth of bad bacteria such as gardnerella spp, mycoplasma spp and streptococcus spp. While the underlying cause remains elucidated, it is believed the abnormal amount/ratio of the sex (estrogen-progesterone) hormones, increase in testosterone in PCOS altered the normal vaginal pH and microenvironment leading to depletion of lactobacillus spp.

Menstrual blood, with the presence of iron can increase the vaginal pH leading to decrease in lactobacillus amount, resulting in dysbiosis of the vaginal microenvironment and bacterial vaginosis symptoms.

Further Impact Of Sex During Menstruation On Vaginal Microenvironment

Sex activities during menstruation can affect the vaginal microbiome. The vaginal environment is unstable during period with depletion of lactobacillus spp. Sexual intercourse without barrier contraception can further disrupt the vaginal microenvironment and increase susceptibility of contracting infections including STDs and bacterial vaginosis.

Effect Of Contraceptives On Vaginal Microbiome

Due to the increasing use of contraceptive methods to prevent pregnancy, understanding the effect of contraceptives on the vaginal microenvironment is important.

Use of spermicides can result in alternation of vaginal microflora. Similarly, physical barrier contraceptives such as condom and cervical cap may be coated with a layer of lubricant/ chemicals or spermicides- have potentials to disrupt the vaginal environment, causing inflammation. Consequently, the vaginal flora can be diversified with lesser amount of lactobacillus spp, and more amount of pathogenic bacteria such as E. coli, Enterococcus spp.

Copper IUD may affect the vaginal microbiome due to long-term presence of a foreign object leading to increase colonization of bacterial vaginosis-related bacteria and decrease in lactobacillus spp.

The clinical literature on the impact of hormonal contraceptives are contradicting although most are favorable towards a stable vaginal microbiome without tempering the amount of vaginal lactobacillus spp. Having said that, it is known that contraceptive hormones can be associated with vaginal yeast infection (candidiasis).

Contraceptive method should be chosen following a patient-physician shared decision after factoring in a person’s health background/ risk, lifestyle and desire for effective birth control and etc.

Effect Of Lifestyle On Vaginal Microbiome

A stressful lifestyle generally puts the body under inflammation. Stress hormones such as cortisol, adrenaline can cause vaginal microbiome dysbiosis by reduction of lactobacillus spp and increase risk of vaginal infections such as bacterial vaginosis or even contracting STDs.

Lifestyle such as douching is a clinically proven cause of vaginal microbiome disruption. Douching is associated with increase vaginal pH, lesser lactobacillus spp and high association with vaginal infections such as bacterial vaginosis.

Is The Vaginal Microbiome Stable After Menopause?

Menopause is a physiological state where a woman has completed her reproductive career. There is a significant reduction in reproductive hormones including estrogen. As a result, in postmenopausal woman, there is significant reduction in amount of lactobacillus spp, and increase in diversity of the vaginal microbiome and anaerobic bacteria including vaginosis-related bacteria such as gardnerella spp and others.

What Should I Do If I Experience Abnormal Vaginal Symptoms Suggestive Of Altered Vaginal Microbiome?

If you have symptoms as below, you should consult your doctor that you are comfortable with.

Vaginal itch
Vaginal abnormal discharge- unusual color, excessive volume, abnormal consistencies
Vaginal odor
Vaginal or lower pelvic pain
Fever
Urinary discomfort

Your doctor will physically examine you and prescribe medications accordingly to treat underlying vaginal infections. Vaginal swab tests or urine tests may be offered depending on your symptoms and condition. Blood tests and ultrasound imaging can be offered if underlying hormone or menstrual disorders are suspected.

Take home message…

Understanding the association between hormonal changes and vaginal microbiome fluctuation allows one to be mindful of lifestyle and potential co-triggers throughout the menstrual cycle.
Understanding and managing underlying menstrual disorders can facilitate a healthy stable vaginal microenvironment thereafter avoid opportunistic vaginal infections.
When considering contraception choices, aside from personal choices, lifestyles and compliance, effect of contraception on vaginal health should be considered to reduce risk of vaginal infections.

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Song SD, Acharya KD, Zhu JE, Deveney CM, Walther- Antonio MRS, Tetel MJ, Chia N. Daily Vaginal Microbiota Fluctuations Associated with Natural Hormonal Cycle, Contraceptives, Diet, and Exercise. mSphere. 2020 Jul 8;5(4):e00593-20.
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