Hyperbaric Oxygen Therapy, Explained Clearly.

Fertility · IVF · Male Fertility · HBOT Research · 8 Min Read HBOT & Fertility: What Does the Research Actually Show? Interest in Hyperbaric Oxygen Therapy and fertility is growing — but the most interesting development is not a broad claim that HBOT can simply “boost fertility”. Researchers are now studying HBOT in specific reproductive contexts, including resistant thin endometrium, poor ovarian response and male infertility. That gives us something much more useful to examine: what has actually happened in human fertility studies? Explore the Fertility Research ↓ In This Article Why oxygenation is being investigated Thin endometrium & IVF research Poor ovarian response research Male fertility research What does the evidence mean? How ReWell approaches fertility Accessing HBOT Common questions The Science Why Is Oxygenation Being Investigated in Fertility? Reproductive biology is complex. Fertility cannot be reduced to one hormone, one organ or one physiological process. What researchers do know is that reproductive tissues depend on blood supply, oxygen delivery, cellular energy and the surrounding tissue environment. HBOT changes oxygen availability in a distinctive way. The HBOT Effect Increased Atmospheric Pressure + Oxygen↓More Oxygen Dissolved in Blood Plasma↓Increased Oxygen Availability During Treatment↓A Physiological Environment Researchers Can Study in Reproductive Tissues This has led researchers to investigate whether repeated HBOT exposure could influence specific reproductive parameters rather than assuming it has one universal effect on fertility. Tissue Oxygenation Increased dissolved plasma oxygen creates a temporary increase in oxygen availability throughout the body. Blood Supply Vascular and tissue responses are particularly relevant when researchers are investigating endometrial development and implantation environments. Cellular Function Oxygen is central to cellular energy production, making metabolic responses another area of interest in reproductive research. These mechanisms explain why HBOT is worth investigating. The research tells us whether measurable reproductive outcomes have actually changed. The Human Research Thin Endometrium & Frozen Embryo Transfer One of the most interesting human studies looked at a very specific fertility challenge: resistant thin endometrium during frozen embryo transfer treatment. Thin endometrium can make embryo implantation more difficult and may lead to cancelled transfer cycles when adequate endometrial thickness cannot be achieved. 2023 Prospective Study · Resistant Thin Endometrium Endometrial Thickness Increased After HBOT The study involved women who had previously experienced at least one cancelled frozen embryo transfer cycle because their endometrium remained below 7 mm despite standard and additional therapies. Participants receiving HBOT underwent daily treatment for at least 10 days during the proliferative phase alongside their routine endometrial preparation. Following HBOT, average endometrial thickness increased from 5.76 mm to 6.57 mm, a statistically significant change. 5.76 → 6.57 mm Significant increase in endometrial thickness Fewer Cancellations Cycle cancellation rate decreased after HBOT Blastocyst Group Higher intrauterine pregnancy rate reported Among participants receiving blastocysts, the intrauterine pregnancy rate was 53.8% in the HBOT group compared with 18.2% in the concurrent control group. The same difference was not seen among participants receiving cleavage-stage embryos. This is an encouraging fertility-specific finding, particularly because the study investigated women with a defined clinical challenge rather than fertility in general. View the study on PubMed → 2025 Research What About Poor Ovarian Response? A different 2025 study investigated HBOT in women classified as poor ovarian responders — another specific challenge encountered during assisted reproduction. The pre-post cohort included 41 women aged 20–45 and compared ovarian stimulation outcomes before and after HBOT. Researchers reported increases in the number of oocytes retrieved, normally fertilised oocytes and available embryos after HBOT. They also reported improvements in measures including follicle output rate and the available embryo rate. Interestingly, their analysis suggested oocyte numbers increased after two HBOT sessions, plateaued around four to seven sessions and did not show further increases beyond eight sessions. This gives researchers a useful signal to investigate further — but because this was a pre-post cohort rather than a large randomised controlled trial, confirmation in stronger controlled studies is still needed. View the 2025 study on PubMed → Male Fertility HBOT Research Is Not Limited to Female Fertility Fertility is a shared picture, and research into HBOT has also examined male reproductive parameters. A 2025 systematic review and meta-analysis brought together randomised controlled trials investigating HBOT for male infertility. 2025 Systematic Review & Meta-Analysis · 9 Trials Several Sperm Parameters Improved Nine eligible studies were included in the analysis. The researchers reported statistically significant improvements across several measures of sperm quality following HBOT, including: Motility Improvement reported Density Improvement reported Viability Improvement reported Morphology Improvement reported Normal Sperm Rate Improvement reported Clinical Pregnancy Higher rate reported HBOT was evaluated alongside conventional treatment rather than as a replacement for standard fertility care. The authors considered the findings promising, while also highlighting the relatively small number of available trials and the possibility of publication bias. View the systematic review on PubMed → The fertility research becomes much more useful when we stop asking whether HBOT simply “boosts fertility” and start asking which reproductive parameters researchers have actually measured. Understanding the Evidence Three Different Research Areas. Three Different Questions. These studies should not be bundled together into a claim that HBOT has been proven to improve fertility for everyone. What they show is more specific — and more interesting. In women with resistant thin endometrium, researchers have reported increased endometrial thickness and encouraging implantation findings in a blastocyst subgroup. In women with poor ovarian response, a recent cohort reported increases in oocyte yield and embryo-related measures. In male infertility, a meta-analysis of nine trials found improvements across multiple sperm parameters and clinical pregnancy rate when HBOT was combined with conventional treatment. Together, these studies give fertility-specific HBOT research a meaningful foundation. They also make it clear that the reason someone is considering HBOT matters. At ReWell HBOT Should Fit Around Your Fertility Journey There is no single fertility journey — and there should not be a single HBOT conversation either. Someone trying naturally has a different situation from someone preparing for IVF. Someone experiencing poor ovarian response has different questions from a couple investigating male-factor infertility. At ReWell, the starting point is understanding where you are in that journey and why you are considering HBOT. Trying Naturally Your wider fertility history, health and goals provide the context for any additional support being considered. Preparing for IVF HBOT should be considered around the timing and recommendations of the fertility treatment already underway. Specific Fertility Challenges Where thin endometrium, poor ovarian response or male-factor infertility is relevant, the research can be discussed in that specific context. If you are undergoing IVF, taking fertility medication or working with a fertility specialist, ReWell recommends discussing additional therapies and supplements with that team. Explore HBOT & Fertility at ReWell → Beyond HBOT Looking for Wider Fertility Support? ReWell's Fertility Support service is separate from HBOT and takes a wider look at your individual fertility journey. Depending on your circumstances, that may include personalised nutrition, lifestyle support, relevant testing and other supportive strategies around natural conception, IVF preparation or a longer fertility journey. Explore Personalised Fertility Support → HBOT Access Explore HBOT Around Your Fertility Plan Depending on where you live, the frequency being considered and your wider fertility plan, ReWell offers clinic, home rental and ownership options. Try Start With a Clinic Session New to HBOT? Experience an introductory session at ReWell in Naas, Co. Kildare and talk through what is involved. 60 minute session €85 incl. VAT Book an HBOT Session → Rent Regular HBOT at Home Research protocols frequently involve repeated sessions. Home rental can make regular access more practical by removing repeated travel to the clinic. From €1,229/month incl. VAT Explore Home HBOT Rental → Own Long-Term HBOT Access ReWell also supplies soft-shell and hard-shell hyperbaric chambers for people who want longer-term access at home. From €9,999 excl. VAT Explore HBOT Chambers → If you decide to purchase later, up to six months of eligible ReWell rental payments can be credited towards your chamber purchase. Personalised Guidance Talk Through Your HBOT Options With Davitt ReWell's HBOT programmes are guided by Davitt Meenaghan, IBUM-certified Hyperbaric Safety Officer. “With fertility, context matters. We want to understand where you are in your journey, what treatment or support is already in place and why you are considering HBOT before talking about how it could fit.” Davitt can talk you through the research, screening, chamber options, pressure, practical access and how HBOT may fit around your wider fertility plan. Talk to Davitt — Book a Free Discovery Call → Keep Exploring Fertility, Research & ReWell HBOT & Fertility Explore how HBOT is being researched around fertility, IVF and reproductive health. Explore HBOT & Fertility → Fertility Support Explore ReWell's separate personalised service covering nutrition, lifestyle and wider fertility support. Explore Fertility Support → HBOT Research Hub Explore published research across fertility, recovery, neurological health, chronic pain and other areas. Visit the Research Hub → Common Questions HBOT & Fertility FAQs Has HBOT actually been studied for fertility? Yes. Human research has examined HBOT in several specific fertility contexts, including resistant thin endometrium during frozen embryo transfer, poor ovarian response and male infertility. The evidence base is still developing, but it now includes prospective clinical research, cohort studies and a systematic review and meta-analysis of male infertility trials. Can HBOT improve endometrial thickness? A 2023 prospective study involving women with resistant thin endometrium reported a statistically significant increase in average endometrial thickness after HBOT, from 5.76 mm to 6.57 mm. The study also reported fewer cancelled cycles. Has HBOT been studied during IVF? Yes. Research has investigated HBOT in specific assisted-reproduction settings, including resistant thin endometrium during frozen embryo transfer and poor ovarian response during controlled ovarian stimulation. These findings should be interpreted in the context of the specific patient groups studied rather than applied to every IVF cycle. Does HBOT improve egg quality? It is more accurate to describe what the research measured rather than make a general claim about “egg quality”. A 2025 pre-post study in poor ovarian responders reported increases in oocyte numbers, normally fertilised oocytes and available embryos, along with improvements in several ovarian-response and embryo-related measures. Larger controlled studies are needed to confirm these findings. Has HBOT been studied for male infertility? Yes. A 2025 systematic review and meta-analysis of nine trials reported improvements in sperm viability, density, morphology, normal sperm rates and motility, as well as an increased clinical pregnancy rate when HBOT was combined with conventional treatment. Can HBOT replace IVF or fertility treatment? No. The studies discussed here investigate HBOT in specific reproductive settings, often alongside conventional fertility treatment. HBOT does not replace appropriate fertility assessment, IVF, medication or specialist reproductive care. Should I tell my fertility clinic if I am considering HBOT? Yes. If you are undergoing IVF, using fertility medication or receiving specialist fertility care, ReWell recommends discussing additional therapies and supplements with your fertility team so that your wider plan remains coordinated. The Bottom Line The Fertility Research Is Becoming More Specific — and That Matters The strongest reason to pay attention to HBOT and fertility is not because oxygen sounds intuitively “good for fertility”. It is because researchers are beginning to test HBOT against specific reproductive challenges and measurable outcomes. We now have human research examining resistant thin endometrium, ovarian response, oocyte and embryo measures, sperm parameters and clinical pregnancy outcomes. These are encouraging areas of investigation. They are also different clinical questions, and the research is at different stages of development. The useful question is not “Does HBOT boost fertility?” It is “What part of the fertility journey are we trying to understand — and what does the research show there?” Explore Your Options Could HBOT Have a Place in Your Fertility Journey? Explore the fertility-specific research, learn more about HBOT at ReWell or talk with Davitt about your circumstances and the practical options for accessing HBOT. Explore HBOT & Fertility Fertility Support Talk to Davitt This article is for general educational purposes and does not constitute medical or fertility advice. HBOT is not a replacement for fertility assessment, IVF, medication or specialist reproductive care. If you are undergoing fertility treatment, discuss additional therapies with your fertility team. HBOT may not be suitable for everyone, and screening and individual suitability matter before treatment.