Inflammation, Hidden Infections and Infertility

I’ve been learning something over the past few months that has changed the way I think about fertility. I want to share it with you while I’m still exploring it. I don’t have all the answers, but I think the questions are worth asking.

When I say “immune system,” you probably picture a runny nose, a sore throat and a week on the couch. That’s certainly part of it. But the more I learn, the more I’m realising how much bigger its role is.

Research is showing that the immune system is involved in ovulation, in making and protecting sperm, in preparing the lining of the uterus, and in whether an embryo is welcomed or turned away. It works hand in hand with the nervous system and hormones. When it’s well regulated, it seems to switch on when needed and back off when the job is done.

But what happens when it doesn’t switch off or when it’s too weak to fight? Researchers are finding that ongoing, low-grade inflammation is a common thread in unexplained infertility, failed implantation and recurrent miscarriage. That has me curious about what might be sitting underneath for some of the couples I see.

“everything looks good… so why aren’t we pregnant?”

This is a story I hear often. A couple has been doing everything right. They’ve worked with a naturopath for two years. I’ve treated them for two years too. The diet is clean, the supplements are dialled in, the bloods look good, and they feel good. And still no pregnancy.

That isn’t a failure on anyone’s part. But it does make me wonder: are there places we simply haven’t looked yet? Standard testing is designed to answer certain questions, and there may be some it doesn’t ask. One I keep coming back to is whether the immune system could be quietly fighting something that never fully left or isn’t responding strongly enough to clear it.

stealth pathogens: the guests who never left

Ideally, when we catch an infection, the body clears it and moves on. But it turns out some organisms are very good at staying:

Viruses that go quiet. The herpes family (including the virus behind glandular fever, EBV) can lie dormant for years and reactivate when we’re stressed or run down.
Bacteria that hide. Some live inside our cells. Others build a protective layer called a biofilm, a bit like cling film, that may shield them from the immune system and from antibiotics.
Infections that routine tests can miss. Organisms like chlamydia, mycoplasma and ureaplasma don’t show up on a standard bacterial culture and need a specific DNA-based test. It makes me wonder how many “all clear” results tell the whole story.

Researchers call these stealth pathogens. The thinking is that if they never fully leave, the immune system may never fully switch off. The inflammation that follows could affect egg quality, sperm, the uterine lining and implantation.

One example is chronic endometritis, a low-grade inflammation of the uterine lining, usually caused by bacteria. It often has no obvious symptoms. It’s thought to affect up to a third of women with infertility, and it’s been linked with repeated implantation failure and miscarriage. What gives me hope is that it appears to be very treatable once it’s found.

the chinese medicine view

What fascinates me is that Chinese medicine seems to have described this long before we had the lab tests. We call it a lingering or retained pathogen: something that entered the body, was never fully expelled, and settled deeper in. Over time it’s understood to create Toxic Heat (inflammation) together with Blood Stasis (poor circulation and stuck tissue), usually on top of some underlying depletion.

It might explain why some people say they’ve “never been the same” since a virus, or why a cycle can change after a bad infection. I find it reassuring when two very different systems seem to be pointing at the same thing.

the symptoms we might not connect to the immune system

One thing that makes immune imbalance hard to recognise is that it rarely looks like “being sick”. It can look like a collection of things that seem unrelated, or that you’ve been told are “just stress” or “just how you are.”

Signs that may be worth exploring:

Energy and mind

Fatigue that isn’t fixed by sleep
Brain fog, poor memory or concentration
Anxiety, feeling wired, or feeling that everything is “too much”
Low mood
Poor or unrefreshing sleep

Skin and sensitivity

Flushing or feeling hot for no reason
Hives, itchy skin, rashes, or rosacea flares
Big reactions to mosquito bites
Hay fever, allergies or sinus trouble
Sensitivity to fragrances, fumes or smoke

Gut and food

Bloating, reflux, nausea or irregular bowels
Food intolerances that keep growing
Feeling unwell for days after alcohol

Cycle and reproductive health

Painful periods, pain with sex, or pelvic, hip or lower back pain
Diagnosed or suspected endometriosis or adenomyosis
Fibroids or polyps that keep coming back
Headaches, skin flares or allergies that shift with your cycle
Recurrent thrush, BV or urinary tract infections
Recurrent cold sores
Unexplained infertility, failed implantation or miscarriage

Body and recovery

Dizziness on standing, or low blood pressure
Aching muscles or joints without a clear cause
Taking weeks to recover from a cold, or never seeming to get sick at all
Feeling “never the same since” a virus or illness
Stubborn weight around the middle or sugar cravings (inflammation and blood sugar seem to drive each other)
Reacting to everything: foods, supplements, weather, even gentle treatments

One or two of these on their own aren’t cause for alarm. But when several cluster together, I think it’s worth getting curious.

it takes two: what about his health?

This is one of the areas that are consistently overlooked.

Research suggests up to a third of men with fertility problems may have an infection in the reproductive tract, often with no symptoms at all. These infections appear to affect sperm in several ways:

Direct damage. Some bacteria seem to stop sperm from swimming and damage their energy centres.
Oxidative stress. The immune cells sent to fight infection release chemicals that may damage sperm too.
Antisperm antibodies. Some bacteria look similar to sperm, so antibodies made against them may end up attacking sperm as well. These antibodies can remain for years after the infection has been treated.

What surprised me most is that a standard semen analysis doesn’t measure any of this. In one study of men with chlamydia and mycoplasma infections, nearly three-quarters had completely normal standard results. Yet a third of their sperm carried broken DNA, around three times the rate in fertile men. Sperm with damaged DNA can still fertilise an egg, but the embryo may struggle to implant or continue to grow.

Couples also share a microbiome. If only one partner is treated, could the infection simply pass back again? That question is why I want to look at both of you together.

why this matters: it’s not just about falling pregnant

When you’ve been trying for a long time, it’s natural for everything to narrow down to one goal: getting pregnant. I understand that completely.

But I keep coming back to a bigger question: what if we’re also working towards a healthy pregnancy, a healthy birth, and the best possible start for your child?

The egg and sperm that may become your baby are developing right now. An egg takes around 100 days to mature, and sperm take around 70 to 90 days. I find myself wondering how much the environment they grow in (inflammation, oxidative stress, hidden infections) might shape them.

Some infections are known to affect pregnancy. A group that includes toxoplasmosis, CMV and herpes (HSV) can pass from mother to baby, which is why some are screened for. Often, though, they’re only looked at once a pregnancy is underway. An active herpes virus may also affect how an embryo develops in its earliest days. It makes me wonder: why not look before conception, when there’s time to calm things down?

Health going in seems to shape the pregnancy. Research suggests that thyroid health, blood sugar and inflammation before pregnancy influence the risk of miscarriage, gestational diabetes and preterm birth. One study found that thyroid levels within the “normal” range, but not optimal, were still linked to higher rates of pregnancy loss.

It’s a family picture. Many of these infections seem to be shared between partners, and sometimes with children already in the home. Caring for everyone’s health may help protect the little one yet to arrive.

Especially important in your late 30s and 40s. The longer we’ve lived, the more viruses, infections and stress our immune system has met. When time feels precious, making sure each attempt has its best chance feels even more important.

what we don’t know yet

There’s still so much science hasn’t worked out. We don’t fully understand how many of these conditions affect a pregnancy or a child’s long-term health. We also don’t know what effect they may have already had on your fertility journey.

I don’t share any of this to worry you. If you’re already pregnant, or already a parent, please know that none of this is about blame. I didn’t know this before I had my girls. So many of these things are invisible, common, and rarely tested for.

But where there’s a chance to prepare, I think it’s worth considering. To me, this is generational health: caring for your own body now so you can pass on the strongest foundation you can.

a gentler order: nervous system, immune system, then hormones

One idea that now looks so very clear is that the order of care matters as much as the care itself.

It’s tempting to go straight to hormones. But if the body is still busy with inflammation or infection, pushing hormones may not help much, and oestrogen may even feed some of these pathogens. So this is the order I’m now exploring:

Nervous system first. It seems the body needs to feel safe before it can heal. A nervous system stuck in fight-or-flight may keep the immune system on high alert.
Immune system second. Gently calming inflammation, looking into what might be lingering, and helping the immune system regulate rather than simply boosting or suppressing it.
Hormones last. Once the ground is clearer, hormones may respond far better, often to much gentler support.

how i’m approaching fertility assessments now: The Search

All of this has changed how I begin working with you, whether you’re coming as a couple or on your own. I call this process The Search: a fertility assessment designed to look at the whole picture.

Step 1: Preliminary testing. I’ll ask you, and your partner if you have one, to complete a set of bloods, so we have a baseline understanding of your overall health. I’ll also gather any investigations you’ve already had, including IVF cycle summaries and naturopathic or functional medicine reports.

Step 2: The sit-down. Both partners together, where applicable. A thorough head-to-toe health history alongside a Chinese medicine assessment and immune health questionnaires to get the fullest picture we can.

Step 3: Your report and plan. I’ll write up what we find in a clear report with a plan. This may look like further testing. This may look like acupuncture for fertility support. Sometimes it may be kinder to restore health first, so your body feels ready to conceive and carry.

exploring the immune system together

I’ve started looking more closely at testing for the immune system, inflammation and the kinds of hidden infections I’ve described here. I want to be honest: this is new territory for me, and I’m still learning. I’m lucky to have a wonderful mentor, Naava Carman from The Fertility Support Company, who has been doing this work in London for years and now uses this framework to support a range of chronic health conditions too. I have a feeling it could be a missing piece for some couples, and I want to take the time to understand it well.

who this might be for

This may suit women or couples who feel they’ve tried everything and are still searching for answers. That might be you if:

you’ve had repeated failed IVF cycles or recurrent implantation failure
you’ve had recurrent miscarriage
you’ve been told you have poor-quality embryos, or your partner has high sperm DNA fragmentation
nothing you’ve done to improve your health or fertility seems to have made a difference
you know you carry a lingering virus, such as herpes (HSV, including cold sores), glandular fever (EBV) or CMV
you’ve had infections such as chlamydia, mycoplasma, ureaplasma, recurrent UTIs, BV or thrush, even if they were treated years ago
you’ve had parasites, or tick bites or suspected Lyme disease
you’ve lived or worked in a mouldy or water-damaged building
you’ve never felt the same since a virus, including COVID or glandular fever
you have endometriosis, adenomyosis or an autoimmune condition
you react to everything: foods, smells, supplements, medications

It may be especially worth exploring if you’re in your late 30s or 40s.

timing matters

Because this work involves exploring first, then calming the immune system before focusing on hormones and conception, it’s best suited to you if you’re:

not actively trying to conceive right now
not pregnant or breastfeeding
not about to start an IVF cycle
at least a month on from your last IVF cycle (so the medications don’t cloud the picture)

I know pressing pause can feel hard. But I wonder whether, for some, this groundwork could be what helps the next step count.

curious about testing?

If so, please get in touch. Once I’ve put together a clear process to help us learn more, I’ll email you with the details.

acupuncture on its own is not the answer

Acupuncture can be powerful, but it won’t fix all of this on its own. What I’m building is a network of practitioners around you, with me as your guide. I’m beginning training in micro-immunotherapy, a gentle approach that aims to help the immune system regulate itself. I work alongside a trusted herbalist, and I’ll coordinate with your GP, fertility clinic and other practitioners as needed.

I’d love to save you the running around, the repeated explanations and the exhausting self-advocacy. You bring your story, and we’ll explore the path together.

This article is for general education and isn’t a substitute for individual medical advice.

I’m not a trained writer, so I use AI to help translate my ideas into something clear and easy to read — the thinking, the story, and the editing are still mine. I’d rather spend my time learning better ways to treat you and help families become healthier, and I’m grateful for the help.