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How Vaginal Microbiota Can Impact Fertility

For women of reproductive age, achieving a successful pregnancy is dependent on the normal function of endocrine hormones (thyroid, adrenal glands and sex hormones) and the health of the reproductive tract environment.

Having balanced sex hormones plays a pivotal role in promoting egg development, regulating cycles and maintaining fertility.

Meanwhile, a healthy reproductive tract (which includes every part of a woman's reproductive organs from the vagina and cervix up to the fallopian tubes and ovaries) promotes successful embryo implantation and supports a full term pregnancy.

female sexual health

Did you know our vaginal microbiome changes throughout a woman’s life?

The composition of the vaginal microbiota is in constant flux and will vary throughout a woman's life. It is greatly impacted by hormonal shifts such as puberty, pregnancy, post-partum and menopause.

During a woman's reproductive years, the hormones that dictate our menstrual cycles, oestrogen and progesterone, have a significant influence on the vaginal microbiome. The levels of these hormones will directly affect components of the female genital tract and defensive barriers, including mucous (discharge) viscosity which changes throughout the month (see our blog on Fertility & Conception for more info), endometrial thickness (the lining of the uterus which sheds each month during a period), immune cells and normal vaginal bacteria. When these hormones are out of sync, it can lead to an imbalance in our ‘good’ bacteria.

The importance of having the right bacteria in the vagina

The vaginal ecosystem has its own very distinct bacterial microbiome. The composition of this is extremely important to our overall health and often gets overlooked when it comes to fertility.

Dysbiosis (an imbalance of healthy bacteria) within the vaginal microbiome can play an integral role in infertility, frequent miscarriage, endometriosis, pre-term birth, frequent urinary tract infections and bacterial vaginosis so its important to know if your microbiome is healthy, especially if you are struggling to conceive.

What makes up a healthy vaginal microbiome?

A healthy ecosystem is mainly dominated by a bacteria called Lactobacillus, which feeds off glycogen (essentially a natural sugar food source) produced by vaginal wall cells. This then produces lactic acid and this acid creates a low pH environment that enables beneficial bacteria to thrive, limiting pathogenic strains (bacteria which can cause infertility) from becoming dominant.

Having a healthy balance of bacteria in the endometrium is fundamental for successful implantation, and low levels can reduce chances of conception.

IMPORTANT FACT! Up to 30% of infertile women have links to pathogenic bacteria in their vaginal tract.

What are the benefits of having a healthy vaginal microbiome dominated by lactobacillus?

- Enhances fertility

- Reduces antisperm immunity (an immune system that attacks sperm)

- Reduces the risk of STI’s

- Protects against UTI’s

- Protects against cervical cancer

vaginal dysbiosis

Common causes of vaginal dysbiosis (which can impact fertility)

Infections are a leading cause of vaginal dysbiosis. Upper genital tract infections can affect areas of the reproductive tract, such as the endometrium, fallopian tubes, ovaries and pelvic cavity.

Lower genital tract infections (vagina, vulva, cervix), most commonly caused by STI’s and can increase the risk of pelvic inflammatory disease (PID).

The most common factors that can displace beneficial vaginal microbes include:

- Antibiotic use

- Spermicides

- Excessive vaginal washing

- Hormonal shifts

- Multiple sexual partners

- Increased frequency of intercourse

- Smoking

- Use of a diaphragm

- Recurrent UTI’s

- Candida (thrush)

- Bacterial Vaginosis

- Group B Strep

How do I know if I have an imbalance in the vaginal microbiome?

Going off any symptoms you may be experiencing will be a good starting point. Are you experiencing any itching or burning, is there a fishy odour or change in discharge smell or colour?

Note that not all bacterial imbalance will have obvious symptoms so as a nutritionist, we will encourage our fertility clients to do a comprehensive vaginal microbiome swab test to check all the levels of good and bad bacteria in the vaginal tract.

Some ‘bad’ bacteria in the vagina can prevent sperm from reaching the egg and overgrowth of pathogenic strains of bacteria such as E-Coli may lead to urinary tract infections which can cause infertility.

What can be done to improve my vagina microbiome if there is an imbalance?

Depending on the exact balance and pH of your microbiome, we are able to use a blend of nutritional support, natural supplements, probiotics and pH balancing products to rebalance the bacteria levels.

It is also quite common that women who have gut issues (such as IBS) likely have an imbalance in their gut microbiome, which means they are more susceptible to UTIs and vaginal infections such as BV & thrush. Therefore it is always important to work from the top down looking at the other microbiomes in the body first (oral and gut) and rebalance those.

If you are experiencing any gut issues then I would highly recommend speaking to a nutritional therapist to rectify this at the same time. A comprehensive stool analysis may also be highly beneficial here too.

If you have been struggling to conceive, exploring in-depth testing of your vaginal microbiome and pH levels could be the missing piece of the puzzle. Sometimes it’s just a case of treating an underlying infection, or rebalancing the microbiota via pre and probiotics through diet and supplementation.

Fortunately there are many natural interventions which can be used to improve fertility so please do get in touch if you are having trouble conceiving.

Do you want support in your fertility and pregnancy journey? Book a free consultation with Gail to find out more.


Gail Madalena

Registered Nutritional Therapist


Gail Madalena is a registered nutritional therapist specialising in fertility, pregnancy and women’s health. Her expertise lies in hormonal imbalances, such as irregular cycles, debilitating PMS, PCOS, endometriosis, thyroid issues and sub-optimal fertility. Her goal is to reduce hormonal side effects and symptoms by addressing the root cause of the issue. Gail helps couples optimise your nutrition and lifestyle choices, supporting you on your journey to achieving a healthy pregnancy.

I am not attempting to prevent, treat or cure any physical, mental or emotional issues. Do not disregard medical advice or delay seeking medical advice because of information you have read on this website. Do not start or stop taking any medications without speaking to your primary health care provider.


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