Infections and Fertility

Infections can impact fertility in a number of ways. They can:

• Inflame the reproductive organs, making it difficult for sperm to reach the egg or for the egg to implant in the uterus.
• Damage the reproductive organs, making it impossible to conceive or carry a pregnancy to term.
• Increase the risk of miscarriage.
• Cause birth defects.

Some of the most common infections that can impact fertility include:

Pelvic inflammatory disease (PID):

In the UK, about 200,000 people are diagnosed with Pelvic Inflammatory Disease each year. PID is more common in young women, especially those who are sexually active.

PID is an infection of the female reproductive organs, including the uterus, fallopian tubes, and ovaries. PID can cause scarring and damage to the fallopian tubes, which can make it difficult to conceive.

It is most commonly caused by sexually transmitted infections (STIs), such as chlamydia, which accounts for around 35% of cases according to NICE (source), and gonorrhoea. PID can also be caused by bacteria that enter the reproductive organs from the vagina or cervix with other causative organisms including Neisseria gonorrhoeae (2–3% of cases), Mycoplasma genitalium, and organisms in normal vaginal flora (such as anaerobes). You can test the health of your vaginal microbiome through at-home test kits such as Daye’s Vaginal Microbiome Screening.

PID can cause a number of symptoms, including:

• Pain in the lower abdomen
• Fever
• Pain during sex
• Abnormal vaginal discharge
• Bleeding between periods
• Nausea and vomiting
• Painful urination

If you are experiencing any of these symptoms, it is important to see a doctor right away. PID can be a serious condition, but it is usually treatable with antibiotics.

How Infections Affect Male Fertility

When we discuss infections and fertility, most attention is directed towards women. However, male reproductive health can also be compromised. Infections such as mumps orchitis, chlamydia, or prostatitis can reduce sperm quality, impair motility, or even block the sperm ducts. In some cases, infections may alter the DNA within sperm, increasing the risk of miscarriage or congenital abnormalities. Early testing and treatment are essential, as prolonged inflammation can cause permanent damage.

👉 In partnership with DAYE, we also support access to innovative at-home vaginal health tests that help you understand your microbiome and take early steps to protect fertility.

Urinary tract infection (UTI):

A UTI is an infection of the urinary tract, which includes the bladder and kidneys. UTIs can be caused by bacteria that enter the urinary tract through the urethra. If a UTI is not treated, it can spread to the kidneys and cause serious health problems. UTIs can also increase the risk of miscarriage.

The good news is that with adequate management it is possible to minimise complications. Available evidence prompts the recommendation of routine screening for asymptomatic bacteriuria (ASB) in early pregnancy to minimise complications and identify those women at significant risk for preterm delivery. This is available through Plan Your Baby. Speak to our fertility experts to find out more.

Bacterial vaginosis (BV):

Bacterial Vaginosis is a common vaginal infection, but is not sexually transmitted infection (STI), instead it is caused by an imbalance of the normal bacteria in the vagina. It is characterised by an overgrowth of predominantly anaerobic organisms and a loss of lactobacilli. The vagina loses its normal acidity, and its pH increases to greater than 4.5.BV can cause vaginal discharge, odour, and itching. BV can also increase the risk of preterm birth and infection of the newborn.

According to the National Institute for Health and Care Excellence (source), about 1 in 3 women in the UK will experience BV at some point in their lives. About 1 in 5 women will experience BV at least once a year. Approximately 50% of women with BV are asymptomatic.

To diagnose BV, your doctor, or chosen specialist such as those fertility specialists at Plan Your Baby, will likely perform a pelvic exam. During a pelvic exam, your doctor will insert two fingers into your vagina while pressing on your abdomen with the other hand to check your pelvic organs for signs of infection. Your doctor may also take a sample of vaginal secretions to test for BV.

BV is treated with antibiotics. The most common antibiotics used to treat BV are metronidazole (Flagyl) and clindamycin (Cleocin). Antibiotics are usually taken by mouth for 5-7 days

Silent Infections: Why You May Not Notice a Problem

Not every infection announces itself with pain or discharge. Some, like chlamydia or BV, can remain completely asymptomatic in up to 70% of cases. This “silent” course means they may only be detected when fertility investigations begin. The difficulty is that scarring or tubal blockage can occur even without obvious warning signs. This is why routine screening, particularly for individuals planning pregnancy, is an evidence-based safeguard against unexpected fertility challenges.

Genital herpes:

Genital herpes is a sexually transmitted infection caused by the herpes simplex virus. It can cause painful blisters or sores on the genitals. Genital herpes can increase the risk of miscarriage and birth defects.

According to the UK’s National Health Service (NHS), around 1 in 5 people in the UK aged 16-49 have genital herpes. This means that there are around 5.6 million people in the UK with genital herpes, of which around 2.8 million are women.

The symptoms of genital herpes can vary from person to person. Some people may have no symptoms at all, while others may experience mild or severe symptoms. The most common symptoms include:

• Painful blisters or sores in the genital area
• Itching or burning in the genital area
• Pain during urination
• Fever
• Chills
• Swollen lymph nodes in the groin

The symptoms of genital herpes usually go away on their own within a few weeks. However, the virus can remain dormant in the body and reactivate at any time. Reactivation can be triggered by stress, illness, or hormonal changes.

There is no cure for genital herpes, but there are treatments that can help to reduce the symptoms and the risk of transmission.

Long-Term Consequences of Untreated Infections

An infection that is not promptly diagnosed and treated may have long-standing repercussions. Chronic pelvic pain, ectopic pregnancy, and recurrent miscarriage are recognised sequelae. Beyond fertility, there are also general health risks such as sepsis or kidney damage. The implication is clear: while antibiotics or antivirals can often resolve acute infections, the earlier they are started, the better the chance of preserving reproductive potential.

The Role of the Vaginal Microbiome in Fertility

We now understand that the vaginal microbiome – the balance of bacteria that naturally protect the reproductive tract – plays a critical role in conception and pregnancy. A lactobacillus-dominant environment is considered protective, reducing the likelihood of infections such as BV or PID. Conversely, disruption of this balance may predispose to inflammation, poor implantation, or even early miscarriage. Simple at-home tests can provide insight into your vaginal health, empowering you to act before complications arise.

👉 To learn more, watch our video Your Vaginal Microbiome: The Hidden Key to Fertility on YouTube.

Partner Screening and Joint Care

Fertility is rarely an individual issue – infections can be transmitted between partners. Treating one partner without assessing the other often results in reinfection. Both men and women should be screened, particularly for STIs. This dual approach not only prevents recurrence but also strengthens the couple’s shared commitment to a healthy fertility journey. At Plan Your Baby, consultations include advice for couples, recognising that joint care leads to better outcomes.

Treatment Options

The treatment for an infection that is impacting your fertility will depend on the type of infection you have. Some common treatment options include:

• Antibiotics: Antibiotics are used to treat bacterial infections.
• Antifungals: Antifungals are used to treat fungal infections.
• Antivirals: Antivirals are used to treat viral infections.
• Surgery: Surgery may be necessary to treat infections that have caused scarring or damage to the reproductive organs.

Prevention

There are a number of things you can do to help prevent infections that can impact fertility, including:

• Practise safe sex: Use condoms to protect yourself from sexually transmitted infections.
• Get vaccinated: Get vaccinated against STIs, such as chlamydia and gonorrhoea.
• Wash your hands often: Wash your hands with soap and water for at least 20 seconds, especially after using the bathroom, before eating, and after changing a diaper.
• Avoid sharing personal items: Do not share personal items, such as towels, razors, and toothbrushes, with others.
• Drink plenty of fluids: Drinking plenty of fluids helps to keep your urinary tract healthy.
• Eat a healthy diet: Eating a healthy diet helps to keep your immune system strong.

If you are experiencing any of the symptoms of an infection, it is important to see a doctor right away. Early treatment can help prevent serious health problems and protect your fertility.

Emotional Wellbeing and Infection-Related Infertility

The diagnosis of an infection that impacts fertility can feel distressing and unfair. Many patients report feelings of guilt, frustration, or anxiety, especially when delays in treatment have already affected their reproductive options. It is important to remember that infections are common and treatable. Compassionate counselling, clear communication, and access to early intervention can make this journey less isolating.

At Plan Your Baby, we offer screening for all the above infections as part of our fertility screening packages. So there is no need to wait and wonder whether these infections or others could be impacting your fertility journey. With Plan Your Baby you will receive same day results and online consultations with top fertility experts. Find out more here

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