If you have been diagnosed with uterine fibroids and you are trying to conceive, the short answer is yes, fibroids can cause infertility. But the more important question, and the one most conventional providers don’t have an answer for, is why your body grew them in the first place.
Fibroids are the most common benign tumors in women of reproductive age, and they show up disproportionately in women dealing with unexplained infertility, recurrent pregnancy loss, and failed IVF cycles. Removing a fibroid surgically without addressing the root cause often leads to recurrence, because you are still left with the same internal terrain that allowed it to form.
Here is what fibroids actually do to fertility, why they grow, and what a functional medicine approach looks like for women over 35.
How Fibroids Affect Fertility
Whether a fibroid impacts conception depends on three factors: location, size, and number.
Submucosal fibroids grow inside the uterine cavity and directly interfere with embryo implantation. These are the most likely to cause infertility, and surgical removal generally improves outcomes.
Intramural fibroids grow within the muscular wall of the uterus. Evidence suggests they can reduce fertility, particularly when they distort the cavity. One synthesis showed a 21 percent reduction in IVF live birth rates with non-cavity-distorting intramural fibroids.
Subserosal fibroids grow on the outer wall and rarely affect fertility unless they become very large or block a fallopian tube.
The mechanisms include altered endometrial receptivity, disrupted uterine peristalsis, changes in implantation gene expression (HOXA10), reduced blood flow to the endometrium, and physical obstruction.
Why Fibroids Grow: The Root Cause Conversation
Conventional medicine calls fibroid causes “largely unknown.” From a functional medicine perspective, that is incomplete. Fibroids are a downstream symptom of identifiable patterns.
Estrogen dominance is the central driver. Fibroids are exquisitely sensitive to estrogen. This is rarely about your ovaries making too much. More often, your liver and gut are failing to clear what is already there.
Impaired liver detoxification. The liver processes estrogen through Phase I and Phase II pathways. When overburdened by toxins, alcohol, medications, or chronic infections, estrogen metabolism slows and circulating estrogen rises.
Gut dysbiosis. Elevated beta-glucuronidase activity unbinds estrogen that was packaged for elimination and sends it back into circulation.
Environmental toxins, including xenoestrogens from plastics, pesticides, personal care products, and mold mycotoxins, mimic estrogen and amplify estrogenic signaling.
Insulin resistance and inflammation promote fibroid growth through elevated growth factors like IGF-1 and chronic cytokine signaling.
Nutrient deficiencies, particularly vitamin D, magnesium, and iodine, are strongly associated with fibroid formation.
The Mold Connection Most Doctors Miss
The conversation almost no provider has had with you is the mold conversation. When I see a woman with fibroids who also has unexplained fatigue, brain fog, sinus issues, fragrance sensitivity, or a history of living in a water damaged building, I always ask about mold.
Mold growing in damp materials produces compounds called mycotoxins. These are fat soluble and persistent. They store in fat tissue, brain, and detox organs. And several of them, including zearalenone, have a chemical structure that closely resembles estrogen.
Zearalenone and estrogen receptors. Produced by Fusarium species commonly found in water damaged buildings, zearalenone binds directly to estrogen receptors. The body cannot tell the difference between its own estrogen and the zearalenone it is exposed to. Both activate estrogen signaling. This is one mechanism behind the rise in estrogen sensitive conditions, including fibroids, endometriosis, and certain hormone driven cancers.
Indirect estrogen burden. Ochratoxin A and trichothecenes burden the liver. When the liver is occupied processing biotoxins, it has less capacity to clear endogenous estrogen. Detoxification slows. Estrogen recirculates. Fibroids have the environment they need to grow.
Inflammation. Mycotoxins activate mast cells, drive cytokine release, and disrupt immune regulation. That low grade inflammation supports fibroid growth and affects egg quality, implantation, and immune tolerance during early pregnancy.
Testing. Mycotoxin testing is done through a urine panel; I most often use Vibrant Wellness’ Toxin Zoomer. Alongside that, ERMI-Plus (with Fusarium spp. add on) dust testing identifies the mold species in your home or workplace. I
If you have fibroids, unexplained fertility challenges, and any of the symptoms above, the mold conversation is worth having.
Why This Matters More After 35
If you are over 35 and trying to conceive, you do not have time to ignore the upstream picture. Fibroids tend to grow during the perimenopausal years when hormonal shifts amplify estrogen dominance. At the same time, egg quality is declining and your fertility window is narrowing. Addressing fibroids in isolation leaves too much on the table.
What a Root Cause Approach Looks Like
When a woman with fibroids comes to me, the first thing I want to understand is the body the fibroid is growing in. Here is what a thorough workup looks like.
Comprehensive hormone testing. I use Vibrant Wellness’ Hormone Zoomer to see how your body makes, metabolizes, and clears estrogen. Standard blood work shows one snapshot. The Hormone Zoomer shows whether your estrogen moves down the protective or inflammatory pathway, how you methylate metabolites, and whether you have enough progesterone to balance.
Gut and estrobolome assessment. Vibrant’s Gut Zoomer shows your gut bacteria, beta-glucuronidase activity, intestinal inflammation, and pathogens. When beta-glucuronidase is elevated, you have chronic estrogen recirculation that liver support alone will not address.
Environmental toxin and mycotoxin testing. Given how often mold shows up with fibroids, I almost always include mycotoxin testing in an initial workup. I also look at glyphosate, phthalates, bisphenols, and heavy metals when relevant.
Nutrient status. Vitamin D, magnesium, iodine, iron, and methylation cofactors (B12, folate, B6) through serum testing and, when relevant, organic acids testing to see how your body is actually using nutrients.
Inflammatory and metabolic markers. Fasting insulin, hemoglobin A1c, hs-CRP, and a full thyroid panel including reverse T3 and antibodies. Subclinical insulin resistance and undiagnosed thyroid dysfunction are two of the most common patterns I find in women whose fibroids keep returning. These are all included in the Comprehensive Blood Panel.
Drainage capacity. Before any aggressive protocol, I want your bowels moving daily, lymph flowing, liver and kidneys functioning, and nervous system regulated. Drainage first – always.
From there, the protocol is personalized to what your testing actually shows. It might include targeted liver support, binders for mycotoxins, microbiome work, vitamin D and magnesium repletion, DIM or calcium d-glucarate for estrogen clearance, and nervous system regulation. The goal is not to attack the fibroid. The goal is to change the environment so it no longer has what it needs to grow.
Meaningful change typically takes six to twelve months. For women over 35 with a tightening fertility window, that is the conversation worth having now.
Frequently Asked Questions About Fibroids and Fertility
Can fibroids cause miscarriage?
Yes. Submucosal fibroids that distort the uterine cavity and large intramural fibroids that interfere with endometrial blood flow both increase miscarriage risk. Many women with smaller or differently located fibroids carry healthy pregnancies. The conversation worth having is not just whether you have fibroids, but where they sit, how large they are, and whether your cavity is distorted.
Do fibroids always need to be surgically removed?
No. Submucosal fibroids that distort the cavity typically benefit from removal if you are trying to conceive. Subserosal fibroids on the outer wall often do not need removal unless they are very large or causing symptoms. What rarely gets addressed in conventional consultations is that if the underlying drivers are not addressed, fibroids return. Surgery is a reset, not a cure.
Can fibroids shrink naturally?
In some cases, yes. Fibroids are estrogen sensitive, so shifts in estrogen metabolism, liver detoxification, and gut health can influence size. Meaningful change typically takes six to twelve months of consistent work. For women over 35 with a tight fertility window, this is worth discussing with a practitioner who can help you weigh the timeline.
Will fibroids come back after surgery?
Often. Within five years of myomectomy, somewhere between 25 and 50 percent of women develop new fibroids. Surgery removes the fibroid but does not change the internal environment that grew it. This is why fibroid management has to include root cause work.
Can I get pregnant with fibroids?
Yes. Many women conceive and carry healthy pregnancies with fibroids present. The question is whether your specific fibroids, in your specific body, are creating obstacles that need to be addressed first. A submucosal fibroid distorting your cavity is a different conversation than a small subserosal one.
