This article is part of the HBOT Radar series, where we summarize the latest published hyperbaric oxygen therapy research.
Fresh Science, Clearly Explained — Brought to you by Brain Spa Hyperbaric
Disclaimer: This article is intended for educational and informational purposes only. It summarizes published medical research conducted in clinical settings and does not evaluate Brain Spa Hyperbaric products. The hyperbaric chambers offered on this website are non-medical wellness devices and are not intended to diagnose, treat, cure, or prevent any disease. Do not make medical decisions based on this article — consult a qualified healthcare professional.
📌 She Wasn't Producing Enough Eggs for IVF. Then Her Doctor Added Oxygen.
🔍 What this study explored
If you've been through IVF, you know the drill: hormone injections for days, monitoring ultrasounds, egg retrieval — and then the anxious wait to see how many eggs were collected and how many fertilized properly. For most women, this process is stressful but functional. But what if your doctor suggested adding sessions in a hyperbaric chamber to the mix?
For poor ovarian responders, it's devastating.
Poor ovarian response (POR) means your ovaries don't respond well to the stimulation hormones. Instead of producing multiple eggs, you get very few — often three or fewer. The embryo quality tends to be lower. Cycle cancellation rates are high. And with each failed cycle, the emotional and financial toll mounts.
POR affects somewhere between 6% and 35% of women undergoing IVF, and it's becoming more common as the average age of first IVF attempt rises. Current treatments — growth hormone, CoQ10, DHEA — have been tried, but the evidence for any of them is inconsistent at best. A 2024 randomized trial in Human Reproduction even called growth hormone in IVF "useless."
So a fertility team at Beijing Chao-Yang Hospital — one of China's leading reproductive medicine centers — tried something different: they added HBOT sessions during the ovarian stimulation cycle. And they didn't just measure whether it helped — they figured out exactly how many sessions were optimal.
🌬️ HBOT protocol used in this study
- Design: Pre-post cohort study (same women compared before and after HBOT)
- Patients: 41 women aged 20-45 diagnosed with POR (Bologna criteria)
- Protocol: 100% oxygen at 2.0 ATA. Total session duration 120 minutes — including 25-30 minutes of pressurization, 60 minutes of pure oxygen breathing at stable pressure, and 30 minutes of decompression. Conducted in multiplace hyperbaric chambers.
- Timing: HBOT started on day 3 of menstruation (the beginning of the ovarian stimulation cycle) and was administered daily or every other day up to the day before the trigger injection
- Comparison: Each woman served as her own control — her IVF outcomes before HBOT vs after HBOT
- Statistical methods: Paired analysis, restricted cubic spline regression (to find the dose-response curve), and generalized estimating equation models
- Funding: National Key Technology Research and Development Program of China
This study was conducted in a clinical hospital setting under medical supervision. Results from clinical research cannot be directly applied to other settings or devices — always consult a healthcare professional.
📊 Key findings
More eggs, better eggs, more embryos
The paired analysis — comparing each woman's results with and without HBOT — showed significant improvements across the board:
- Number of oocytes retrieved: significantly increased after HBOT
- Follicle output rate (FORT): significantly increased — meaning a higher percentage of antral follicles actually produced mature eggs
- Follicle-to-oocyte index (FOI): significantly increased — more follicles converting to retrievable oocytes
- Normal fertilization rate: significantly increased — more eggs fertilized correctly (two-pronuclear stage)
- Available embryos: significantly increased
- Available embryo rate: significantly increased
In plain language: after adding HBOT, these women produced more eggs, more of those eggs fertilized normally, and more resulted in usable embryos. For women who had previously struggled to produce even three eggs per cycle, this is a meaningful shift.
The sweet spot: 4-7 sessions
This is what elevates this study beyond a simple "it works" finding. Using restricted cubic spline regression — a statistical method that maps non-linear dose-response curves — the researchers found a clear pattern:
- After 2 sessions, oocyte numbers began to rise significantly
- Between 4 and 7 sessions, the effect plateaued — maximum benefit
- Beyond 8 sessions, there was no further increase
The relationship was statistically non-linear (P = 0.016), and it tells a practical story: you don't need dozens of sessions. Four to seven HBOT sessions during the stimulation cycle appears to be the sweet spot. More doesn't seem to help.
This kind of dose-optimization data is rare in HBOT research. Most studies test one protocol and report whether it worked. This study mapped the curve — which is far more useful for clinical decision-making.
🧠 Why this study matters
Fertility is one of the most emotionally charged areas in medicine. For women with POR, every IVF cycle represents thousands of dollars, weeks of physical discomfort, and enormous emotional investment — often with disappointing results. The idea that something as non-invasive as a few oxygen sessions could meaningfully improve egg yield and embryo quality is, if confirmed, genuinely significant.
The biological rationale is solid. The ovary depends heavily on angiogenesis — the growth of new blood vessels — to supply follicles with oxygen and nutrients during their rapid growth phase. Hyperbaric oxygen therapy is known to stimulate VEGF (vascular endothelial growth factor) and promote angiogenesis. It also reduces oxidative stress, which is considered one of the key mechanisms behind poor ovarian response, especially in older women. And it triggers the hyperoxic-hypoxic paradox — where intermittent high-oxygen exposure actually improves the body's ability to handle oxidative stress.
The honest caveats:
- Pre-post design with no separate control group. Each woman was compared against herself, which eliminates between-person variability — but it doesn't control for other changes between cycles (different hormone protocols, time effects, clinic learning curve).
- 41 patients is a modest sample. Enough to detect the observed effects, but a larger randomized controlled trial is needed to confirm.
- No pregnancy or live birth rate data. The study measured eggs and embryos — the intermediate outcomes. We don't know whether the improved embryo quality translated into more pregnancies or babies. This is the outcome that ultimately matters.
- Single center in Beijing. Replication in other populations and settings would strengthen confidence.
Despite these limitations, the dose-response curve — showing a clear plateau at 4-7 sessions — adds credibility. Random noise doesn't produce clean non-linear dose-response patterns. Something real appears to be happening.
📌 Takeaway for the community
- 41 women with poor ovarian response showed significantly more eggs, higher fertilization rates, and more usable embryos after adding HBOT to their IVF stimulation cycle
- The dose-response curve identified 4-7 sessions as optimal — beyond 8 sessions, no further benefit was observed
- This is one of the first studies to combine HBOT with IVF specifically for poor responders, from one of China's top reproductive medicine centers
- Without a separate control group or pregnancy outcome data, the results are promising but preliminary — a randomized trial with live birth rates is the next step needed
- This study was conducted in a clinical hospital setting under medical supervision — results cannot be directly applied to other settings or devices
Source: https://rbej.biomedcentral.com/articles/10.1186/s12958-025-01475-z
Meng W, Zhu W, Song Z, Pan Y, Xing X, Guo J, Pang L, Meng F, Zhang Z, Li J, Yang J, Lu Q. Hyperbaric oxygen therapy improves oocyte yield and embryo quality in poor ovarian responders: a pre-post cohort study. Reprod Biol Endocrinol. 2025;23:142. doi: 10.1186/s12958-025-01475-z.
Educational disclaimer
This content summarizes findings from published medical research for educational purposes only.
The hyperbaric chambers sold on this website are non-medical wellness devices and are not intended to diagnose, treat, cure, or prevent any disease.
The studies discussed here were conducted in clinical medical settings using medical-grade interventions. The inclusion of research summaries does not imply that similar outcomes can be achieved using non-medical wellness devices.
